Project "Ultimate 1983 Rabbit GTI"
Index of Project web pages
Project Overview, Goals & Initial design specs
Project car initial condition
Bodywork & Paint
Suspension, Wheels, Tires & Braking System
Engine & Transmission
Electrical & Fuel System
VW Vortex Thread on this project
My original 1983 Rabbit GTI (owned 1983-1987)
I am documenting my whole project on video here, beginning to end:
Part 1 (intro) - February 1, 2013
Part 2 (building a frame to flip the car) - February 8, 2013
Part 3 (engine development at Mark's VW Service, Amity, Oregon) - February 15, 2013
Part 4 (a review of the exterior seam sealer removal process/rust inspection) - February 22, 2013
Part 5 (a review of the interior seam sealer removal process/rust inspection) - March 14, 2013
Part 6 (showing the rolling chassis stand, the test mounting of the aftermarket inner & outter fenders, and the initial engine bay smoothing process) - April 6, 2013
Part 7 (showing the process to clean up the original OEM fenders, given that the aftermarket ones were poor fitting and could not be used) - April 10, 2013
Part 8 (showing the process of welding in the upper/inner fenders and relating metalwork in the front engine bay area, as well as the initiation of the engine bay smoothing task) - May 4, 2013
Part 9 (Completing the metalwork in the front engine bay area, the completion of the engine bay smoothing task, and the initiation of the front-to-rear frame connector welding process) - May 19, 2013
Part 10 (Completing the welding of the front-to-rear frame connectors, floor pans, additional OEM floor pan bracing, and new 'lift points') - June 9, 2013
Part 11 (Having a look at the beautiful and extremely light weight carbon fibre body panels and bumpers made by LWS Design for this project. I am super impressed with their customer service as they hand delivered everything to me at the London Heathrow airport before 7am at no charge! The full set of scratch resistance polycarbonate windows will ship separately later this summer) - June 19, 2013 ...
Part 12 (Any time you try and MIG weld thin sheet metal you risk 'blow-thru' and this is especially true with older vehicle sheet metal where there has been some rust. I wanted to try my hand at MIG 'brazing' using the same modern European techniques that are required when working with thin boron doped high strength steel panels and/or zinc plated panels - in either case MIG welding puts too much heat into the base metal and both weakens it and vaporizes the protective Zinc coating. So I managed to source some 0.035" diameter MIG brazing wire and adjusted the settings on my welder to lower the wire feed speed but keep the voltage/temperature setting the same as for my 0.023" dia mild steel wire. It worked! The bronze flowed into the gaps and in between the overlapped metal on the lower rear quarter panel patch and I did not once blow-thru the base metal. Highly recommended for sheet metal restoration work) - June 24, 2013 ...
Part 13 (After doing quite a bit of MIG brazing I am more impressed with its capabilities and versatility than ever. This video covers some of that brazing work plus it covers the fabrication and installation of the remaining interior chassis stiffening components) - July 10, 2013 ...
Part 14 (Finally! Chassis welding is completed and I managed to get the under carriage epoxy primed today) - August 10, 2013 ...
Part 15 (Since August 10th (above) I applied body filler to all of the under carriage welding seams, sanded it down, and then applied more 2 part epoxy primer, then applied seam sealer only to the areas where there were actual gaps in the seams/metalwork (seam sealer can promote rusting if water can get behind it so it is better to avoid over doing it), then I applied rubberized undercoating in the rear wheel wells and the very back corners of the under carriage where the wheels will throw up rocks and dirt, which will eventually be painted silver aka OEM look, but again, I won't apply under coating anywhere else (I will use some interior sound deadening material under the carpets to control road noise rather than mess up a lot of nice clean sheet metal). I will now work on the rest of the chassis and then when everywhere else is up to this level I will re-apply epoxy, then 2K high build primer, then block sand where appropriate, then epoxy as a sealer, then silver base coat and then clear coats, in that order) - August 18, 2013 ...
Part 16 (I have managed to get 2 coats of epoxy primer on the front end with final body filler/smoothing applied/sanded between coats. This is a huge milestone for me as I can now clearly see the car coming together. It is rewarding to see how well the engine bay smoothing turned out too) - August 29, 2013 ...
Part 17 (And now the first coat of epoxy primer is applied to the interior sheet metal with body filler on the welded seems coming next) - September 1, 2013 ..
Part 18 (The interior sheet metal areas were treated to some body filler on the welded seems and then it was shot with some reduced grey color epoxy primer acting as a sealer and then some base and clear coats to complete the interior) - September 14, 2013 ..
Part 19 (With the interior done I carefully masked off the whole car, including all interior to exterior holes and got ready to start the bodywork on the exterior panels, starting with the lower sills which were pretty badly abused by the prior owners, so I had to start by using a block of wood and a hammer to straighten out the underside area running beside my 1.5x1" subframe, and then block sanding and filling until everything was straight [still a work in progress]) - September 22, 2013 ...
Part 20 (Well, I finished the drivers side lower sills and flipped the car around and started working on the passenger side sills. After 4-6 hours of work they are almost straight now and getting close to the finishing putty stage. I have a full week of travel in front of me starting Wednesday so won't get this finished for another 2 weeks though - October 14, 2013 ...
After a few more passes of putty I sprayed on some high build primer and found that pretty much everything was straight and clean except for a small area at the back of the door edge that I had over sanded along the crease, hence the additional putty in that spot. I have also managed to get 4 passes of filler and putty on the rear passenger lower corner where I had braised in a new panel) - October 29, 2013 ...
Part 21 (I have made good progress on the welded area in and around the fuel filler cap, the rear passenger fender lip, smoothing out and correcting a curvature issue around the side signal light, finishing the lower rear passenger corner where I had previously braised in a new panel, and cleaning up the area around the rear license plate lights) - November 5, 2013 ...
Part 22 (I have now completed the bodywork on the passenger side and have block sanded a number of times, sprayed epoxy twice with touch-up putty applications in-between and now it is ready for 2K high build primer) - November 20, 2013 ..
Part 23 (I put in about 15 hours this weekend doing a final epoxy primer sanding to the passenger side, then applying 2 coats of 2K high build primer (but I got some nasty runs in the paint because I put on too much - but it sanded out easily later ...), then I waited overnight to block and detail sand out the high build primer (which turned out great - really smooth and flat), and then I dropped the car down onto the roller frame, unbolted the rear bumper, sanded down the old paint on the rear, and then got the first coat of filler and block sanding done on the rear before dinner time) - November 24, 2013 ..
Part 24 (I have spent quite a bit of time on the rear drivers side getting the panel absolutely correct. There was a soft dent in the area and after a lot of careful layer by layer buildup of filler I found that I had to go wider and wider to acheive the perfect curvature that was required. It is 90% now and so I decided to epoxy prime it at the same time as I did the initial priming of the rear this weekend so that I can see the reflections on the surface when I complete this task. i am very happy with the way the rear turned out as there is only minor touchup that will be required. I hope to get those minor things addressed tomorrow so that I can finish the weekend with a 2K high build primer application) - November 30, 2013 ...
Part 25 (I got the 2K high build primer applied to the rear at the end of the weekend, sanded it down yesterday, did some minor putty touch-up today, shot those areas with a bit more epoxy, and then moved on to the drivers side. I sanded it down today and shot it with an initial coat of epoxy so I can lay on some filler and putty starting tomorrow) - December 3, 2013 ...
Part 26 (Over the past week I managed to get several passes of filler on the drivers side and another coat of epoxy, then more filler and sanding, then some touch-up epoxy on the areas that I cut thru to the base metal, and a lot of work getting the depth and profile on the edges of the molding crease at the back of the car (using a near little metal tool I shaped to create the correct depth and shape), then today managed to get the high build primer on (and after some block sanding once it dries I will move on the engine bay for the final touch up filler, etc and then the roof)) - December 8, 2013 ...
Part 27 (I spent the past week working on the engine bay, completing the final smoothing filling and sanding process, spraying epoxy when I needed to see how close I was getting, and eventually I got to the point of completing the high build primer application and started on the final block sanding of all of the surfaces prior to the base/clear painting process which I will tackle in January. I also got the critical front window frame areas all completed which is very satisfying ... and thanks to Kevin Young, a fellow VW Vortex member, I had access to one of his mint NOS GTI badges to get a correct colour reference to compare both my original faded badges as well as the aftermarket Mk1autohaus replicas - it turns out that the repro rear badge wasn't even close but the front was) - December 18, 2013 ...
Part 28 (The Christmas holiday period was focused on family and nursing a bad cold. It was only in the last few days that I had the time and energy to get back into the GTI project in full force. I put time into dialing in the front, especially the uneven factory spot welding area below the bumper. With the high build primer sanded today it all looks great. I then moved on to the roof and sunroof area and got it DA sanded, etc. and then cleaned up the inside sunroof channel area and sprayed everything with 2 thick coats of epoxy (time for a new epoxy gun as it was not the smoothest application). High build primer will go on later this week after some more sanding of the epoxy) - January 12, 2014 ...
Part 29 (The roof/sun-roof area got a couple of coats of high build primer on it this week and then got block sanded and is now ready for final paint. I then pulled out the fenders and set to work finishing the process of stripping them down to bare metal as well as carefully banging them into the correct shape. It took several attempts with some nasty chemical stripper to get the critical areas looking perfect, then it was on to some final sanding and then water-born cleaner before 2 coats of epoxy primer were applied today. I will now start the process of filling and block sanding to get them straight/correct) - January 17, 2014 ...
Part 30 (I finished the front fenders on Thursday with some more sanding/filling/epoxy and then 3 coats of high build primer and then sanding them out to 600 grit, and then rubberizing the insides - I am really pleased with the results. So Friday it was on to the doors, first stripping them down and then cleaning them out (boy they were filthy inside). Only today did I finally get to the point of prepping them for initial epoxy priming. The biggest challenge I ran into was a frozen passenger side mirror which would not rotate (cast aluminum oxidization) so I could not access the screw heads. In the end it was a long tiring job using a dremel tool to grind down the screws from inside the door and drilling them out. Now I need to weld up the holes and re-tap them. Oh well, no pain, no gain, right?) - January 26, 2014
Part 31 (While I wait for the new door hinge pins from vwheritage, as well as the tools to replace them, I completed the cleaning/prep/sanding of the doors and managed to get them epoxy primed over the past few days. The doors are large and heavy and there is simply no way to paint them end-to-end in one go so the process of completing the painting will be x2 slower than for the fenders - side 1, then wait 24hrs and then side 2, etc.) - January 30, 2014 ...
Part 32 (I got the doors finished a few days ago and I am really pleased about it all - they are straight and clean end to end after putting in a ton of work on them. So it is on to the final 2 body panels: the sunroof and the front spoiler. Other than the somewhat intricate sunroof dissassembly, the sunroof painting is very simple - I will have it completed tomorrow after the application of high build primer and some blocking out. The spoiler is a more complex process that involved removing the metal bracing, and sanding everything down to the original primer and/or bare urethane, and then filling in the dents and holes that were drilled by the former owner with flexible 3M filler, and then more sanding, the application of 'plastic kote', then epoxy, and then high build primer mixed with flex agent - which I will get done tomorrow. I did manage to fabricate an aluminum brace for the lower lip and also used a heat gun to straighten the spoiler to its original shape) - February 9, 2014 ...
Part 33 (Today was the big day: time to mount the primed spoiler to the front of the chassis, align it such that the curve at the lip of the spoiler was perfectly balanced all the way across, and then remove the protective covering of the 3M double sided adhesive/tape that was attached to the aluminum brace I fabricated, and then clamp it into position. I was nervous that I wouldn't get it all aligned correctly but it worked out fine - especially the additional aluminum supports that help attach the lower lip to the body. I then got the high build primer on both the sunroof and the spoiler. This was my first time using Flex Agent and I was really impressed with the results: the normally thick paint which likes to clog up the fine holes in my spray guns flowed super smoothly and went on like melted butter. Wow. It looks so good I almost don't want to sand it - but I will tomorrow after I let everything cure for a full 24 hours) - February 10, 2014 ...
Part 34 (I got the sunroof and spoiler sanded out today. The spoiler was a thing of beauty when I was done as the flex agent seems to enhance the smoothness of the high build paint. The sunroof still had some low spots so I hit it with more high build primer and then blocked it again and finally it was mint.
I then started on prepping the carbon fiber hood for primer and found only a few low spots so I started to get excited about how quick this phase of the project was going to be. Ha! I was badly wrong. I said to myself 'Gee, you haven't test fitted this thing to the body. What if the alignment of the front end is off, or this aftermarket hood is dimensionally different?' Well, good thing I went to all of the effort to re-mount the fenders, install the grill, tune everything until it was 'final' and then I bolted on the hood and found that it had an interference fit to the rain tray lip. Not a huge issue in and of itself - the brace which runs across the back of the hood needs to be cut down by around 3/8" in some areas and re-glassed. Then I said to myself, I never really liked the huge OEM hood gaps and now is the time to do something about that: so I will also extend the sides and back by around 1/8" so that the gaps are the same as for the rest of the body panels on the car. Lots of work but this way I get the alignment and gaps on the front of the car looking really 'high end') - February 11, 2014
Part 35 (The last 2 nights have been carbon fiber hood clearancing (cutting up expensive stuff) and panel gap analysis and preliminary fitting. After filling the garage full of fine carbon dust and getting the hood to sit correctly I was better able to determine next steps with panel gap setting and/or hood width/length/height modifications. In the end I realized that I needed to get everything else to be in its final position before going any further with the hood and that meant hanging the doors and then getting the fenders true to the door gaps. I managed to hang the doors without help from anyone else which was a bit of gymnastics and once done I could see that I was already pretty close on the fitment - it looks like all I will need to do is adjust/blend in the height of the hood against the fenders and then I should be pretty much OK - I decided after hanging the doors that the OEM 1/4" gaps are std everywhere on the car and it wouldn't be smart to setup the hood for a narrower gap fitment (I am very close to 1/4" gaps on the hood on all sides already and only need to adjust the fenders in about 1/16" on each side)) - February 13, 2014 ...
Part 36 (This weekend has been focused on getting the panel gaps perfect everywhere and then starting the process of leveling up the hood. Setting the gaps is an exercise in compromises: first you have to set the fender-to-door gaps such that the doors will just barely clear the fenders when opening/closing, plus the fender height needs to be such that the side moldings and creases all align, and finally, that the hood gaps are equal and approx 1/4" each: the front plastic grill also acts as an absolute reference, determining the left/right position of the fenders at the front (the grill edge and the fender edge should be the same).
My problem is that with everything set correctly the fenders stick out at the front/bottom about 1/16" so when I get 0.020" shim washers I will attempt to reduce the door-to-fender gaps a slight amount, hoping to get the fenders to align a bit closer at the front (even though this misalignment is pretty much hidden/covered by the spoiler, the bumper and the grill which sticks out and blocks the view of it).
I put lots of passes of Evercoat Rage Extreme filler on the hood edges, and then got the first few passes of finishing putty on and all blocked to align the edges precisely with the top of the fenders, and finally, I fabricated an aluminum channel to better support the center-rear area of the hood where I had to cut away the supports to clear the edge of the rain tray - I will fiberglass that channel into place once I finish the edge profiling and absolutely true up the center-rear hood to the body) - February 16, 2014 ...
Part 37 (After getting the hood perfectly level relative to the fenders and cowl I temporarily glued a supporting truss across the back of the hood in order to 'hold' the shape until I could fiberglass in a support next to the rain tray on the underside. I also extended the front lip of the hood down 3/16" with short strand fiberglass and then rounded it nicely to match the OEM hood profile more closely. Finally I finished off the hood with epoxy primer and high build primer/block sanding, etc. I am now ready for the rear hatch which I also test fit to the car this week (and yes, it needs lots of work to fit perfectly - at least I am now an 'expert' with the hood work last week under my belt)) - February 23, 2014 ...
Part 38 (I am now deep into the rear hatch fitting process and it is turning out to be another exercise in almost completely assembling the rear of the car to get everything in alignment - the tail lights themselves have proven to be a challenge on several fronts: first of all it became clear that the driver side rear corner metalwork (all OEM from the factory) isn't the right shape and lacks the dual V taper into the lower edge of the hatch which the passenger side correctly has. It isn't a disaster as we are only talking about 3/16" but it impacts the interface with the hatch and the tail light such that both the hatch and light will have to be re-shaped to follow the metalwork 'as is' (it is simply not a reasonable alternative to try and reshape the body metalwork).
I mounted the hatch first, then realized that I needed to mount the lights, then I further found that I needed to install the hatch seal which pushes the bottom of the hatch lip out a bit, etc. After some grunting and groaning and some careful slotting of holes and a bit of grinding, everything started to come into their final resting positions. I then started to cut, sand and fill the hatch areas as required. This process will take several more days as there is a fair amount of tuning to do - I also need to get the hatch latch installed before I go any further in the tuning process but from this point onwards I think it is a well understood path that is similar to the hood work last week) - February 26, 2014 ...
Part 39 (The rear hatch is now finished and ready for final paint. It took more time than expected to get everything dial in. First there was the tricky and exacting process of taping up and extending the edges to maintain the target 3/16" gaps on the top and sides and 1/4" on the bottom, and then there was incremental work to make both the inside surfaces and edges look OEM (fiberglass and carbon panels are never finished nicely on delivery - there is always fitting and finishing work - the surfaces aren't totally flat and the edges are rough cut, etc). Anyway, I decided to do a nice job as this was the last panel and it is something that I will be staring at inside and out over and over again once the project is complete) - March 5, 2014
Part 40 (The early mk1 style carbon fiber bumpers are the last items to prepare for final paint. It took a week to get them dialed in due to the requirement to fiberglass in the front turn signal openings as I wanted to have the more delicate look of the thinner early mk1 bumpers but with the 1983/84 model look (black, no turn signals). After the fiberglassing there was a lot of fussing to get the surfaces perfectly flat and contoured. And since the bumper material was so thin/flimsy they required a fair amount of filling and block sanding to get nice and flat on the tops and bottoms. Mission complete/major milestone, after I pick up my engine, trans and SS exhaust from Techtonics Tuning/Josh tomorrow I will start to clean out the garage and get it dust free and setup for the critical final panel painting process) - March 11, 2014
Part 41 (I drove from Vancouver, Canada to Techtonics and Josh's engine shop in Sheridan & Amity, Oregon over the past 2 days and picked up the completed 2092cc 9A/ABF engine, 020 transmission, SS exhaust system, 100mm axles/Hubs/spindles, and lots of other parts and drove them back home in the back of my Prius late at night! Josh really pushed to get the engine completed for me and I am very thankful for his late nights and careful work. He did an excellent job of profiling the combustion chambers to match the piston domes and ended up with a compression ratio of 11.8:1 which should run on 94 octane pump gas without octane boost when the weather isn't too hot (the sport cams have enough duration and overlap that they bleed off some of the compression at lower engine rpms). We will dyno it and expect 240hp at 8000rpm with the 288 degree TT solid lifter sport cams with DLC coated lifters. We will also add 60hp with a dry flow progressive nitrous system for a total of 300hp. This should add up to 6lbs/hp in the car if it weighs in at the expected 1800lbs. What a beautiful engine ...) - March 14, 2014
Part 42 (I haven't been snoozing over the past month. The opposite is true:
I have designed and ordered all of the electronics components for the engine management, sensors/senders, a custom serpentine system for the water pump and alternator, a custom Denso style racing alternator, billet pulleys, brackets, and more. There are a lot of things ongoing in regards to sourcing and designing the custom cooling system, hoses and brackets as well that I have been deeply involved in. Photos and videos of all of that cool stuff will be posted soon.
I completely cleaned up/out my garage, loaded up my car and took most of the stuff that wasn't immediately necessary to my expanded storage locker, and started to get ready for final paint. Along the way I got a little carried away and sold my drill press, MIG welder and plasma cutter, and replaced them with a digital TIG welder, a milling machine and a lathe - so I am now ready for aluminum and stainless steel welding, and lots of fabrication of custom brackets to help finish off this project with nice touches everywhere.
I decided to get the seats completed and also get the rear trailing arm suspension unit completed - all before final paint. The main reason is that spring is now here and the painting weather is getting better and better each day and I just don't want to have to fight the cold and the moisture during the critical final paint phase.
I busted my butt scraping, grinding, sanding and acid etching the rear trailing arm suspension over the past week. It was pretty rusty and therefore I took a lot of time to fill all of the pitting and smoothing all of the parts before painting with multiple coats of epoxy. I am waiting for some SPI black epoxy which I will use for the final coats. I will also press in the Delrin bushings soon.
I have a great seat guy that has already cut all of the GTI midnight blue fabric and sewn in the 1/4" foam on the backs of each of the 'panels' while I have been welding up the seat frames where they are weak and tend to flex and crack around the tops of the front seat frames. I also custom cut some extra firm foam for the seat bottoms - a tough, delicate process when shaping the side bolsters. I will finish painting the seat frames when my black SPI epoxy arrives and then my seat guy will finish them off. BTW, I was able to purchase new plastic replacement parts from VW Air Heads and will color match them soon.) - April 14, 2014
Part 43 (I got the 'paint booth' properly setup for final paint with 3M Dust control fabric on the walls of my garage, 3M static dust spray on the concrete floor, and 2 double-filtered fans pulling clean air into the garage (providing a positive pressure environment). I then set about spraying base/clear on the sunroof and the insides of the fenders, and also shot final black epoxy on the bumpers and rear beam axle and completed pressing in the Delrin bushings.
I also picked up the complete ECU system (sourced from Kinsler Injection) - boy there are a lot of wires that will need to be connected. I also picked up the remaining engine sensors and plumbing components from Techtonics) - May 4, 2014
Part 44 (I got Greens Automotive in Richmond, BC to carefully re-straighten, re-weld, re-machine (inside and out) and paint these 14x6 OEM Snowflakes and then mount super sticky Dunlop Direzza ZII track/sport tires. The look I am after is old school - not the current fad of using 8" rims and stretched 195 tires, but never-the-less, with serious performance capabilities) - May 9, 2014
Part 45 (EAA Engineering's Serpentine Belt System, Fluidamper, and Denso Racing Alternator (all put together with clear anodized billet aluminum CNC mounts) - a must use system to clear the ITBs, plus the NOS Wizards Quadranoid, dry flow injectors and small ID plastic tubing. Note, in this video I mis-spoke by saying the stock crank to alternator pulley ratio is 2:1 - I meant 3:1, and therefore changing to a custom 2.5:1 ratio was required due to my higher rpm limit and the 20,000 rpm alternator limit) - May 9, 2014
Part 46 (After successfully completing the final painting of the fenders and rear hatch, the hood turned out to my greatest painting challenge to date: a few spots of dark colored dust contaminated the first clear coat and in the end I had to sand back down and redo the base coats and re-clear but as of tonight it is all looking good. I am especially fond of the carbon fiber underside treatment (with the idea being that the exterior of the car and the interior are totally stock looking but under the hood it is all 'business')) - May 14, 2014
Part 47 (After getting final paint on the front spoiler earlier this week, it was finally time to remove the doors from the chassis and then dive into the process of fabricating brass bushings and shims for the lower door hinges and then hammering the pins into place, test mounting to make sure the hinges are 'good to go' and then getting the final paint on the 1st door. Mission success, now it is on to door #2 tomorrow) - May 19, 2014
Part 48 (I got the hinges done on door #2 with an even better press-fit than door #1 and then got the door based and cleared properly so I was able to flip the chassis on its side and get epoxy sealer, base and clear done on the underside, wheel wells and most of the engine bay area. I will turn the chassis upright tomorrow and finish the engine bay area off and then will move to the rear, top and sides over the next week) - May 25, 2014
Part 49 (Final paint complete. What more can I say? Major project milestone in the can. Yes! When I get back from a trip next weekend I will start wet sanding and polishing the clear (once it is good and firm). And I am already planning out the braking system and fuel system routing under the chassis so that I can use the chassis flipping system one last time before dismantling it and mounting the suspension/wheels) - May 30, 2014
Part 50 (Final paint has now been wet sanded/polished. It took a full month part time to go thru the process of 1500/2000/3000 grit wet sanding of all surfaces and panels, then 3M PerfectIt rubbing compound and then polishing compound using a variable speed Makita orbital polisher. But it is done and the results are A1. I have a some 'craters' in the clear on some of the surfaces that I have filled with additional clear with a tiny paint brush and will finish sanding them out later this week and then I will start to assemble the car) - July 6, 2014
Part 51 (After I pushed the completed chassis out of the garage and into the bright summer sunshine 1 week ago I could see that I had some quite noticeable fine sanding scratches showing thru the basecoat on the roof line edges and I also noticed on the passenger rear quarter panel that the basecoat was not perfectly consistent - a bit of a halo was showing above the fender where I had gone over the area one last time and left a slightly dry edge to the silver basecoat up above that point. So I took a cold shower, swore a few times, and then decided to wet sand the roof, sides and back of the car and re-spray it. And for good measure I sanded down the driver door as the clearcoat was quite thin after all of my sanding and I wanted to have it perfect. BTW, bright silver is considered one of the toughest colors to work with and I have now learned that you need to finish the primer stage with at least 1000 grit, not 600 grit.
All of this re-painting effort got me to thinking how much my paint compressor setup sucks. I have a very small garage and simply can't fit in a 60 gallon 5hp compressor so I have beem trying to make do with a 15 gallon 1.5hp compressor. On smaller panels with my Eastwood HVLP guns I can get by OK, but on bigger jobs like the roof and sides/rear chassis I run down my compressor and have to pause to let it catch up which risks paint drying and losing my wet edges. I also had some problems with moisture in the line, some dirt in the paint, and not enough pressure to the gun so I changed my whole setup: I put a plywood box around my compressor housing with a fan to do a better job of keeping it cool while making less noise pollution; I ran new lines and fittings with less restrictions; I soldered up a 25' copper air cooler/drier; I bought a 30 gallon tank to give me more air reserve; and finally I bought a professional air filter/drier system. And I tested it out this week (still waiting on the 30 gallon tank though) and my guns have all of the air pressure they need, plus the air is totally clean and dry now. Yes!!! With the 30 gallon tank coming, I'll now have 3x total air supply before running low even though my compressor will may need to catch up occasionally.
My rear seats are done now and they look 100% OEM new. Wow. My front seats are 80% done but we ran out of the vinyl that I had dyed Midnight Blue so I had to produce more of it this weekend so we can now get the front seats completed. I managed to get all new plastic parts for the seats too and dye them the correct color so I am really excited about seeing the final results in the next short while.
I am also working on the brake system: I have a combination of SAE double flare and metric bubble flare fittings because of the Wilwood proportioning valve so I have been practicing my flaring technique which is now pretty solid so I will start to bend and flare/assemble the whole brake system soon. I also need to make up a custom bracket to mount the proportioning valve immediately below the master cylinder.
I am also 90% done the design of the fuel system and have almost all of the components in hand. I am in the process of epoxy coating the fuel tank so that I can mount it and start to run the lines, pump, filters, etc.) - July 20, 2014
Part 52 (The front seats are now complete. Sweet indeed! I am also about 30% finished repainting the chassis) - August 5, 2014
Part 53 (With the final painting complete I can now get on with planning and executing the fuel and brake system installation. With the fuel tank temporarily mounted I was able to fabricate a stainless bracket to mount the fuel filters and pump between the rear axle and spare tire well. I also mounted the brake booster and new aluminum 22mm master cylinder with a stainless bracket holding the Wilwood proportioning valve. Now that I have ordered the Davies Craig electric water pump and digital controller it was time to prepare the OEM water pump by cutting off the impeller, aux water return ports (which will be tapped and plugged), and smoothing the interior for its new function as a passive entry way into the block from the outlet of the EWP) - August 17, 2014
Part 54 (I have now setup and started using my Caswell Zinc-Cadnium plating system so I now have a nice looking steering rack again after re-plating the h/w and epoxy painting the housing (but before the installation of the new Quaife close ratio gear set which I am picking up in the UK on Sept 16th).
It was a tight sqeeze but I managed to route the fuel tank breathers together such that I can now install a rollover valve in the fuel filler neck area of the wheel well. I got the pump and filters final-mounted and the hoses routed as well. The Techtonics SS 2.25" exhaust system installation has also started but I was very frustrated with a few things that are only partially resolved at this moment: a serious interference fit with the driver side tank strap which required that I fabricate a bracket to allow the removal of the strap, plus I can't get the resonator to sit in the middle of the tunnel without an interference fit with the front hanger on the side of the tunnel (I think I will end up cutting and rewelding some pipe to solve this). The bottom line is that all of the really hard problems with the fuel system are now behind me and the exhaust system issues are on the way to being solved. I will need to mount the engine and exhaust racing header before making any final decisions on the exhaust system though) - September 1, 2014
Part 55 (Rough positioning of the Techtonics stainless custom 1-3/4" headers and 2-1/4" exhaust system plumbing (note, we are keeping the pipe size at 2-1/4" because this is the size that TT says has proven to produce the most power in normally aspirated cars: 2-1/2" is only suitable for turbo engines, plus a comparison of the old (OEM) and new (Borgeson) steering U joint assemblies, and the new lower steering column bearing and bearing support bracket) - September 8, 2014
After testing out the Borgeson u-joints I found that they did not have enough range of motion for the vw mk1 application. I am now sourcing mk3 u joints (one end has the 11/16" diameter 40 spine u joint so I hope to use them) - October 31, 2014
Part 56 (After a lot of machining and fiddling around I managed to complete the custom front cylinder head coolant outlet flange that is required to clear the ITBs and associated linkage, nitrous and vacuum lines, etc.
After speaking with Techtonics about the exhaust system clearance issues I cut off all of the tunnel flanges and bolts, filled, sanded, primed and painted it all so now there will be nothing hitting the pipes. I also sourced a really nice and small Vibrant stainless resonator that will be welded onto the back of the flex coupling: this way I will havee 2 resonators plus a muffler so that I can make 'quiet power' which is my goal.
The shifter housing has also been cleaned iup and epoxy painted and I have zinc/cad plated all of the hood and hatch brackets, hinges and mounting h/w - plus I now have the ability to chromate as a final step so these parts, plus the steering rack brackets, and many more items are all looking nice (I will post photos and a video of these items and the plating process I am using later on).
I completed the rear axle Delrin bushing/bearing setup/installation with the brass and stainless steel sleaves to take up all excess 'slack' in the system but realized, after speaking with Lella Motorsport who make the bushing,s that I went over-board. I have decided to remove the stainless sleaves I made that are only 0.2mm thick and placed between the 12mm bolt and the Delrin steel bearing insert surfaces so allow for a bit more movement so that the axle will pivot around the 12mm bolt without the potential for binding.
Finally, I have been running the 3/16" (4.75mm) brake lines all over the car this week but I ended up making some crappy looking flares with the manual flaring tool that I had sourced so I have now ordered a MasterCool hydraulic flaring tool to allow me to make OEM quality flares every time. There is nothing more annoying than spending 1/2 an hour making the perfect brake line and then messing it up with a poor flare end - I do not want crappy looking flares and really don't want leaks in my brake lines either) - September 14, 2014
Part 57 (I have been busy using my Caswell Zinc/Copy Cad plating system to rescue all kinds of brackets and bolts since I have not been able to complete my brake lines until the MasterCool flaring tool arrives (ETA tomorrow). I plated the metal objects that were OEM plated and stopped there but for those parts that were originally painted black I first stripped them down, acid etched, plated and chromated them to provide an extra measure of protection before painting) - September 23, 2014
Part 58 (This has been a big week with lots of progress. I completed plating/painting of the headlight housings, the various motor mounts and shift linkages, and the heat shielding applied to the underside of the chassis. My brake line flaring problems were solved with my new Mastercool hydraulic flaring tool and my brake lines are now complete (and wrapped in plastic to protect them from chassis rubbing). I also got the Quaife quick ratio steering rack installed, complete with a new bushing to provide zero play in the system) - September 28, 2014
Part 59 (The rear end is complete and torqued to spec, the steering rack and shifter linkage is now mounted in the front and now I am getting ready to flip the chassis upright for the last time ... and the 020 2Y German Transaxle of America transmission with Quaife LSD is sitting here, waiting for the custom clutch/pressure plate which Josh says will ship to me later this week ...) - October 6, 2014
Part 60 (I got the steering wheel back from Custom Craft today: they re-wrapped the wheel with 1mm of foam and then soft leather. I am very pleased with the end result: a very nice feel to it, not too soft, not too firm, just the right diameter, with the stitching where my fingers want to engage it. I will treat the leather to match the soft gloss of the vinyl center section) - October 8, 2014
Part 61 (With the help of my wife I moved the engine, stand and hoist from my office to my garage last weekend so the GTI is now happily sitting next to the motor and trans. Josh is shipping the clutch tomorrow so I will have everything in hand to install the engine/trans this weekend! I will lift the chassis up using my come-alongs one last time, roll the engine/trans together under it, lower the chassis one last time onto jack stands, use the hoist to lift the engine/trans into place, bolt it up, and then mount the front suspension, brakes, steering, etc. mount the wheels, and then roll the car out of the garage so that I can dis-assemble the lifting frame to make room for the rest of the final assembly. In another week things should start to get pretty exciting.
I also finished machining the new cam hall sensor housing and it is all perfect except for the fact that the hall sensor itself seems to be dead for some reason (a new unit, go figure). So I have ordered another sensor and when I get it later this week hopefully I will be able to test it out and then mount it on the cam/engine ...
There have been so many other small things that I got done over the past week: removing and re-installing a lot of engine accessories, putting the gaskets in place, applying sealant, threat locker, washers, etc into place and torquing things up so that I now am close to being ready to install the engine with all of the accessories already 'final' mounted this weekend) - October 21, 2014
Part 62 (Major Project Milestone: Today was the big day - getting the clutch setup done, and then assembling the engine and transaxle, rolling it under the chassis and then hoisting it into place. Everything went well except for the fact that I had to remove the rear engine/trans mount to get the side mounts to line up first which is a lesson learned, and I also discovered to my dread that I will have to mandrel bend the intake runners another 20 degrees or so to clear the hood) - October 25, 2014
Part 63 (With the engine/trans installed everything else is coming together quickly now. I got the front suspension, front and rear brakes, CV/axles, test fitted, and sorted out missing h/w and such. I also worked on the exhaust system, starting to weld up a header support bracket and otherwise test fitting everything, and fiddled a lot with the steering system, realizing that the Borgeson u joints will not work so I am in the middle of attempting to fit some mk3 parts into place over the next week or so. If all goes well I should have all of the major mechanical systems completed by mid-Nov. I also got the fuel system lines final installed,which required the fabrication of some stainless brackets, and more -6AN SS lines/fittings. I am still waiting on a few hose ends but otherwise the fuel system is basically complete now. I am building a structural support brace for the race header that connects the lower end of the header back to the base of engine block to keep the stress levels on the flanges to a minimum. I am also in the middle of planning on how to bend my intake runners using some structural epoxy molding equipment and some low melting point metal to act as a 'mandrel' internal tube support when I put the bending forces on the tubes - this process will take most of the month to sort out as I don't want to screw it up and will have to practice a bit ...) - November 2, 2014
Part 64 (The completed structural support brace for the race header was electrocleaned and the header itself was ported and polished and has now been sent out for internal ceramic thermal barrier coating. After accidentally throwing out the old rear drum brake mounting h/w I had to source the hard to find M16x1.0 axle nuts and retaining washers again (from Jim Ellis VW), plus I sourced nicer/stronger class 12.9 mounting bolts so the rear disks are now complete. I will put on the wheels and measure clearance to the fenders, measure camber and toe, and then order custom axle/wheel spacers from Lella AutoSport to get the desired offset, camber and toe settings) - November 11, 2014
Part 65 (When I upgraded to the larger 22mm master cylinder (to provide the additional volume of stroke required for the rear disk brakes) I needed to pair it with a later model brake servo/vacuum unit - the problem is that the later model servo has a different rod end. The original 83 GTI servo rod end is longer and has a fixed clevis. It is nicer to have an adjustable clevis so I am going to cut off the original clevis, thread it M10x1.5 and use a coupling M10 nut to mount it to the later model servo.
I completed the exhaust system this week. The V-band clamping system I have used allows me to quickly swap the cat converter in/out in favour of a high performance resonator that will keep noise levels down to where I want them (a total of 3 'straight-thru' resonators make up the entire system). I polished all of the components, and finally the 2.5" tip now sticks out the back end and says 'we mean business' ) - November 23, 2014
Part 66 (I finished the design of the custom aluminum radiator, drew up the drawings and specs, and sent it off to Ron Davis Custom Radiators in AZ. It will be 11"x30"x2", tucked under the front cross member, with ORB o-ring type bungs that mate to ORB-to-AN fittings and then the lines (-20 for the water pump inlet, -16 and -12 for the cylinder head outlets, -10 for the heater core return, -6 for the expansion tank, plus a temperature sensor bung for the electric water pump) and I will be using 2 SPAL 10" medium performance fans with a puller shroud. I have mounting tabs on the top and ears on the sides of the bottom corners - it should work out nicely and provide lots and lots of cooling. I also have a Mocal inline oil-to-water heat exchanger with -20 water fittings and -8 oil fittings - I could not use the factory setup due to conflicts with the ITBs and this system is higher performance and also included a 200 degree F oil thermostat.
I did get the 1989 cab servo modded to accept the 83 GTI servo clevis by cutting off the GTI clevis end, turning it down on the lathe to 10mm diameter and then threading it. With the coupling nut I can now vary the length of the shaft to get the ideal pedal position. I also worked on assembling the clutch/brake/accel pedal assembly and decided that some nice 0.2mm thick 16mm ID 24mm OD stainless shims would remove the factory slop in the pedal assembly, removing the ability for the pedals to shift side to side. The plastic bushings were fine. I also sourced a brake pedal return spring from an 89 cab, complete with a nice plastic/rubber donut sleeve that slips over the 83 GTI pedal shaft and drilled a few holes for a bolt that allows me to adjust the spring tension to suit my tastes - there was no return spring in my car when I took it apart but the manual shows one and I feel that it is probably a smart idea to have one installed - and I do like the idea of being able to adjust the brake pedal spring ...
I have also been noodling away on solving my problem of the ITB intake runners being too high. This problem was caused by not remembering that the ABA block is a lot taller than the earlier mk1 and mk2 blocks. In fact my second injector fuel rail is close to hitting the hood as well! Anyway, I sourced high strength molding epoxy and built a cardboard mold in the shape of the runner OD to allow me to create upper and lower molds of the runners, which are 45mm ID, 48mm OD. I then mounted the epoxy molds onto steel plates and use threaded rods to allow me to apply bending pressure to increase the bend another 10 degrees or so - but after all that work it failed so I have ordered 48mm T304 tubing mandrel bent at 30 degrees from the UK and new inlet/outlet collars from AT Power that I will glue on after cutting to the right length.
I have also been farting around with the shifter linkage. I sourced adjustable end-link components but realized that the vertical shift lever in the engine bay was mounted in a way that hit the other shifter bracket beside it and the only way to solve that problem was to rebuild the clamp on the bottom (where it was hitting) 90 degrees rotated - so I took it apart, ground and reshaped it, and re-plated it so ... tonight I got the shifter linkage installed and all dialed in using the Techtonics shifter kit plus the 4crawler adjustable steel end links which allowed me to get the 1-2 gate positioned exactly where I wanted it (just to the right of the reverse lockout). I will get the brake system/pedal assembly done this weekend ...) - December 9, 2014
Part 67 (I should have all of the new intake runner components by Jan 1 so in the mean time I have been getting a lot of other things done:
I realized that once I have installed the brake servo I will no longer have access to the drivers side of of the steering rack so I took off the steering rack boots one last time, carefully centered the rack and then adjusted the tie-rods to the factory spec, and double checked that I had equal lock-to-lock distance with the steering wheel, etc. - good thing I check again as I was off by about 5mm on the tie-rod positions.
With the 16x24mm shims in hand I was able to shim out the pedal cluster and get it rock solid. With the 1/2x20 jam nuts I was able to use the brake pedal switch to align the brake pedal with the clutch pedal (which has fixed stops and therefore acts at the reference position). Once the servo was installed with the pedal cluster I used my new brake clevis adjustment coupling nut to maximum advantage and got the clevis to the exact position to not move the brake pedal out of alignment with the clutch pedal - awesome.
I then put in all of the final hardware and torqued down the servo, master cylinder and prop valve, and connected all of the brake lines. Since I had never completed the hard lines to the rear disks I fabricated those, and got the rear brake system completed as well. I will pick up my Castrol SRF Racing brake fluid this week and will then flush the lines and get the brake system completed next weekend ...
I also got shims for the accelerator pedal so that it was rock solid as well, and then measured and cut the new AT Power accelerator cable, and grafted on all of the required OEM parts to make the connection thru the firewall to the pedal (I ditched the foam grommet in the center of the accel pedal in favor of a hole in the top of the pedal with the accelerator cable running directly to it for a more positive feel/responsiveness.
Finally, I got the clutch cable installed. Boy that racing clutch is pretty stout feeling. Manageable, I think. I estimate that it is 30% stiffer than the brake pedal feels without brake fluid in the lines pressing on the servo diaphragm.
So the pedals and the shifter all work now. Pretty cool to be able to press all of the pedals and play with the shifter, moving into all of the gear positions. Vroom, vroom ... - December 15, 2014
Part 68 (I received my shipment from Any-Exhaust-Part of the UK for the 48mm T304 intake tubes today and so I could not resist cutting them up immediately and test fitting them to the throttle bodies. Success! I now have the right angle and length to avoid hitting the hood, leaving enough room for the radiator/shroud/fans and the proper geometry for an efficient cold air intake box. I will still have to wait for AT Power to ship me the new collars as it is a real bitch to unglue the ones on the existing intake runners (and then I have to machine the collar IDs about 1mm to fit the new tubes once they arrive)) - December 17, 2014
Part 69 (While I patiently wait for the new custom radiator and intake runner collars I have started to rebuild the heater box with a new heater core, blower, foam pads and seals - again, I must wait for the parts to arrive before being able to re-assemble it so I am going to have to find other things to do for the next week) - January 8, 2015
Part 70 (I wire brushed, acid etched and plated the metal h/w for the heater/blower box, and dove into the door assembly/finishing tasks, starting with the reconditioning of the window channel guides which were rotted out on the bottoms and required TIG braising in new metal, filling, sanding and painting, and also got the design for the 2 way component speaker system that will be installed in the doors sorted out (a high end Hertz HSK 165 system with a 6.5" woofer and 1" tweeter - I will also use hertz coax speakers in the stock front/rear locations, plus a Hertz Sub box in the rear that I can remove along with the sub amp when I want less weight for racing, etc). I also got the metal side plates for the front spoiler stripped, acid etched and primed, plus got the mirror bases acid etched and the whole assemblies partially cleaned up prior to painting) - January 12, 2015
Part 71 (I bit the bullet and upgraded from the Holley HP EFI system to the full Holley Dominator EFI system with its endless # of inputs and outputs. In the end I needed to control more things like 2 PWM fan outputs, a PWM water pump output, and more sensor monitoring (e.g. a second water temperature sensor in the radiator allows me to monitor the difference between the rad and block temperatures and adjust pump flow rates and/or put a restrictor plate into the system to avoid 'block shock'). I am also going to use the Racepak UDX LCD console which communicates with the Holley EFI ECU via can-bus.
I got the prep and painting of the front window channels, front spoiler side plates, and mirrors completed this weekend. It all turned out very well but I think I will wet sand and polish the black epoxy paint parts as those parts ended up being a bit too shiny for me - I want a semi-gloss look and when you wet sand and polish black epoxy it comes out pretty much exactly semi-gloss (soft gloss).
With the new ITB intake runner collars now in my hands I was able to get the intake system completed: I previously sourced new 48mm stainless tubing that was pre-bent at a 30 degree angle, cut them to the right length, ordered new collars, machined them to match the tubing exactly, made up the back plate for the air intake box, glued the collars onto the runners, assembled quickly, aligned, and will let sit overnight to cure. Now I can start to fabricate the rest of the air intake box. No more interference with the hood!) - January 18, 2015
Part 72 (I made satisfying progress this week on the fabrication of the intake vacuum plenum, related sensor mounting, and all of the machining and tapping of the various connectors, including the nitrous solenoid. I was missing a 1/16 NPT tap in my tool chest and there was no supplier open today with the part I needed so I have ordered it from Amazon and will finish the tapping of the 4 ITB vacuum lines later this coming week. I also made an important decision to make the air box out of clear Lexan and put 2 of 2.75"x2.6"x12" K&N air filter elements (they provide 50 sq. inches of pleated filter element per unit) between the top of my custom radiator and the cross member, creating a Lexan funnel into the filters in front of the radiator, and then having a straight shot into the air box, rather than trying to create a long indirect 3 or 4" tube to pull in cold air from under the car (I am really excited about this new idea and think it will work out perfectly)) - January 24, 2015
Part 73 (Over the past few days I managed to work on the cooling system after receiving some of the key parts - unfortunately, the Davies Craig electric water pump -20AN fittings weren't properly machined so I will not be able to finish this until new fittings are sourced. I also had another delay with the completion of the custom radiator - in fact we are starting over with a 1" narrower radiator core so that the side tanks are a full 2" wide to allow for the proper mounting of the -20 ORB fitting and other fittings. The new core will be in the hands of the fabricator Tuesday and with any luck I will have the completed rad in my hands in another week ... I also got the 1/16"NPT tap for the ITB vacuum lines so made more progress on the intake system, plus I got the K&N air filters, the speedo electronic speed sensor for the 020 trans, and a few other items. Finally, I ordered all of the components for the nitrous 'push' system which I will cover in a future video: it consists of a 4500psi air tank, a high pressure solenoid controlled by an adjustable pressure switch, and a normal nitrous tank: the pressure switch is set to 950psi and opens when-ever the nitrous pressure drops, allowing high pressure air to 'push' into the nitrous tank and keep a consistent pressure at all times, regardless of nitrous level or temperature. This is a much more involved system than a bottle warmer and obviously reacts instantly to keep the pressure constant as the nitrous is flowing ... stay tuned for more info) - February 1, 2015
Part 74 (After zinc plating the h/w and cleaning out the heater box, I reassembled the unit with a new heater core, new fan/motor, and new gaskets/seals and tested it out. I also finished drilling the intake air box backing plate for the purge solenoid and mounting h/w, wet sanded all of the aluminum parts up to 2000 grit to prep for anodizing. Best news yet is that my custom radiator shipped out to me Fedex on Friday so I should have it Wed latest and can then complete the cooling system and intake system which are all interrelated. I also received the replacement -20AN fittings from Davis Craig by overnight Fedex (they paid the shipping - 2 thumbs up!) from Australia, no less) - February 8, 2015
Part 75 (Fedex delivered my shiny new custom radiator from http://www.bsandbradiator.com/ today. A quick test fit confirmed a proper fit under the hood and so I was able to order all of the remaining hose end fittings and start to plan out the fabrication of some stainless brackets to support the water pump and coolant-to-oil intercooler. Tomorrow I will pick up a lot of goodies including the remaining air box components, nitrous system components, etc.) - February 11, 2015
Part 76 (I got the Hella 20A solid state relays from Summit Racing and connected them to a signal generator, a battery and the radiator fans and tested out the variable speed control that will be managed by the Holley Dominator ECU - it all worked nicely with 30-40Hz being a good frequency choice, and 20% being a reliable starting point for low speed use - anything more than 80% duty cycle made the fans run close to 100% speed so the range is 20-80% that I will program for. I also realized that I needed to rebuild the wiper motor internals before re-mounting the wiper assembly. I was going to also mount the heater box but it will block my ability to put sound dampening material on the firewall so that will have to come first and I need warmer temperatures in the garage for that - otherwise the material won't adhere fully and won't conform easily to the uneven metal surfaces so I'll do it in a month or so.
I am about to head off on a 2 week trip so won't get much done between now and March 1st ...) - February 15, 2015
Part 77 (After a number weeks of business travel I managed to make some GTI project progress this weekend, first installing the re-built wiper motor assembly with new rubber grommets, and then test fitting some new coolant hose-ends in preparation for this week's task of putting together the remainder of the air intake system, fuel system and coolant system. I also got a chance to run some more air flow testing on the low profile SPAL radiator fans (yes, they flow a lot of air when mounted to the rad, more than enough). I also brought back my new Lexan Margard windows from the UK last week. AWC Motorsports Plastics in Bristol made them and they are perfect with nicely beveled edges (unlike the rough cut Lexan windows that LWS Design in the UK made for me in 2013 - that were made from the wrong material and for a mk2). And I finally sourced all of the fittings required to create a 'push' compressed air nitrous system (4500psi carbon air bottle with a 2900psi output regulator, a 3000psi solenoid, a 550-1250psi adjustable nitrous pressure switch, and the tricky NTP to BSPP adapter required to connect the air quick-disconnect fitting)) - March 8, 2015
Part 78 (This last week I got the custom radiator mounted properly, sorted out more of the coolant fittings, discovered a major interference issue with the -16 upper hose running into the vacuum plenum, built a number of Lexan air boxes (a few fails and then a successful one), and ended the weekend feeling pretty happy that things were coming together as (almost) planned. I also got my nitrous bottles filled and played around with the system a bit more: I will be doing PWM calibration testing on it this coming week) - March 15, 2015
Part 79 (Over the weekend I setup the nitrous system properly on the bench with the custom high pressure air 'push system' and ran a series of linearity tests while pulse width modulating the trick new Quadranoid solenoid (from NOS Wizards in the UK). I consumed 20lbs of nitrous doing all of the tests and learned a lot about the optimum settings for that solenoid. I don't want to run a lot of nitrous in my car as it could hurt my beautiful engine with its ultra precise tolerances (nitrous rapidly increases the combustion temperatures and in turn causes the pistons to expand, etc.). I only want a range of 15-60hp under computer control, not 100hp+.
When I initially installed the 20hp jets, instead of seeing 20/40/60/80hp at 25/50/75/100% duty cycle, I got a range of 80-110hp using a frequency of 35Hz. It turned out that while the Quadranoid is rated to 50Hz, it needs to have the plunger adjusted (a unique NOS Wizards feature) to a minimum height so the range of motion is dramatically reduced, and then it can be accurately controlled at high frequencies. With the seat height at the stock full open setting the plunger just floats when modulated at anything more than 15-20Hz and that is too low of a frequency for my application (intake valves open and close 60 times a second at 8000rpm). While 35Hz, which is the limit for my Holley Dominator ECU, is below the rate of intake valve opening at max rpm, I am feeding the modulated nitrous into a small chamber in the base of the Quadranoid, and then thru the distribution block/jets and then thru tubing to the intake runners: by the time the PWM controlled nitrous comes out the end of the tubes it is almost flowing smoothy - it has a slight pulsing to it but not a ton.
I found that even with the seat height set fairly low the Quadranoid still flowed a ton of nitrous so I switched to the 15hp jets and set the seat height even lower - almost off. And then I got the #s I was looking for: 15/30/45/60hp at 25/50/75/100% duty cycle. One thing I am really interested in is seeing if the 15hp setting will actually produce more like 25hp due to the cooling effect that nitrous has on the intake charge. Nitrous provides additional O2 but it also cools as it vaporizes so even really small amounts of nitrous can add significant power. I am not interested just in peak hp, I want to use the nitrous at the mid-range to tame the 288 degree cams and add back in some of the mid-range torque that is lost due to excessive cam duration ...) - March 24, 2015
Part 80 (After realizing that the new custom radiator had a nasty interference fit between the upper -16 hose and the intake system vacuum plenum log I got busy and ordered up another -16 ORB bung, cut a hole at the bottom of the tank (too bad, it would have been better to have the hot coolant enter at the top) and got my buddy Danny Beaudry of Pro Gas Engineering to weld it in (I am not up to par on tricky aluminum TIG welding like this when it involves a combination of thick and thin materials plus when it has to be leak proof). I then mounted the radiator coolant recovery tank on the side of the fender and started to make up the coolant hoses (a job I will finish in the next week) ...) - March 24, 2015
Part 81 (I got all of the cooland hoses complete, plus the remaining fuel system hoses, and the bracket fabricated to mount the coolant-oil intercooler - it turns out that there is no need to make up another electric water pump supporting bracket as the -20AN coupler to the radiator plus the -20AN short hose connection to the coolant-oil intercooler supports the EWP extremely well. I had trouble making up the -4AN vacuum lines that run between the vacuum plenum and each throttle body but I ended up ordering a Kool Tools stainless braided line funnel tool and cutting shears that should make the task of threading the cut hose into the hose ends for these really small -4AN hoses less of a torture session, complete with blood all over everything ...) - April 4, 2015
Part 82 (I got the plastic nitrous injector lines cut, heated/shaped and installed, plus a number of other intake system plumbing jobs like finishing the assembly of the -4AN hose ends for the vacuum lines, plus sorted out a new approach to my oil-to-coolant intercooler mounting which was to machine a block of aluminum to allow the lower oil fitting to stick out sideways rather than straight down (designed but not yet machined), and the big job for the week was the installation of the GTMAT 110 sound damping material on the interior of the chassis (to reduce panel vibration from the engine and exhaust areas)) - April 12, 2015
Part 83 (After Joey on YouTube suggested I try a banjo type hose end fitting for the oil line that connects to the bottom of the oil-to-coolant intercooler, I got to thinking that a banjo type fitting wouldn't likely flow as well as another similar idea: machining a block of aluminum to allow a right-angle mounting of the -8AN fitting off the side of the housing. I got to work today in my machine shop and now it is all together and the oil line is now slightly above the bottom lip of the chassis so I no longer risk hitting a critical oil line on a block of concrete or road hazard) - April 13, 2015
Part 84 (The oil-to-coolant intercooler mounted up nicely with its new painted bracket, plus the oil lines were done and routed cleanly without rubbing against any painted surfaces (I did cutoff an unused bracket extension from the side of the starter motor to provide more clearance). With this job complete I have finished making all of the Stainless AN lines so I removed all of them from the engine and washed and blow-dried the lines so I can now install them permanently later this week when I will also install the heater core and air box inside the passenger compartment) - April 20, 2015
Part 85 (After fighting with the old heater valve cable for about 2 hours (trying to lubricate it so that it would slide smoothly and open/close the heater valve) I gave up and found a replacement Gemo p/n 161819837 on ebay that looks like it will work fine in my mk1 application. I then fitted up the remaining cables that were in perfect working condition and mounted the heater/HVAC box in the chassis with its new gaskets. I was then able to hook up and complete the coolant system lines in the engine bay and pressure test the complete system to 15psi - success! I was also able to install many of the engine sensors and started to design a mounting bracket for the Holley Dominator ECU and ignition coils that will be placed in the rain tray on the passenger side (it is all weather proof but won't really see any water where it will be placed)) - April 25, 2015
Part 86 (I am starting to lay out the wiring harnesses and plan my connectors (a combination of metripack and weatherpack connectors). I had to cut away all of the electrical tape on the main ECU wiring harness as Holley had placed the fuel pump & injector relay and fuse in a crappy location for my project, same with the main power fuse.
I semi-finished my ECU/ignition system mounting system/plate, ordered and wired up the custom Magnecore KV85 silicon ignition wires and fabricated a wiring loom to hold the wires to the back of the cylinder head. I am pretty happy with how they look.
I sorted out the remaining engine sensors and tested/modified them to suit my project. The cam and crank sensors have given me the most challenges. I had to basically build a custom cam sensor earlier on in the project, and for the crank sensor I adapted a late model Bosch hall effect sensor that didn't quite fit the VW ABA block so I had to grind away at it a lot and also solder up a custom connector that would not hit the block but in the end I was rewarded with a high quality digital output to the ECU. For the cam sensor I got it setup properly to trigger at 180 degrees before Cyl #1 TDC which is what the ECU wants to see. Just prior to firing up the engine for the 1st time I will test all of the ignition timing with the injector harness disconnected.
Here is a list of the main engine sensors (email me if you need the p/ns for the mating connectors):
Bosch KS-R knock sensor, p/n 0 261 231 047 (analog peizo output, ECU set to monitor at 7.2kHz)
Bosch Hall-Effect Speed Sensor HA-P, p/n 0 232 103 037 (requires 1k pullup output resistor)
BBHME2000 Hall- Effect Cam Sensor (requires 1k pullup output resistor)
I sourced some very sticky Hoosier A7 tires in 205/50-15 size (the A7s run 'out of the box' at lower temperatures than the A6s which need quite a bit of heat to work properly. Since I will be drag racing and auto slaloming my GTI the A7s are a better choice for me). THe A7s are mounted on Enkei racing rims (rims weigh 9.9lbs and the total wheel/tire combination weighs 27.3lbs vs 33.5lbs for the VW snowflakes and 185/60-14 tires). The total tire width of the A7s is almost 2" greater than the 185/60-14s and they barely fit with only 1/8" inside clearance to the shocks/springs/struts front/rear. I will use these tires at the track and to test the ultimate performance envelope of the GTI when it is completed. My suspension is a race setup with Bilstein race struts and shocks (p/n V36-0059 & B46-0657-H1) and H&R race springs (400lbs/in front and 285lbs/in rear) and it will be setup with only a moderate ride height drop in comparison to stock as I like 3/4" gaps to the wheel wells - and this will also allow me to fit these wide A7 tires without rubbing too much.
What a heart breaker: After searching endlessly on the internet I finally located NOS VW front windshield glass at VW Parts Place Inc in Michigan ('genuine VW glass' is what they list on their web site) but they would not ship it to me on the west coast - in store pickup only. So I ended up paying them $400 in shipping to get it loaded onto a pallet in a huge box and trucked it out. Buggers! It is Chinese glass and it has a non-stock tint bar across the top which would definitely identify my GTI as a non-stock car (besides the fact that I would hate staring out the window at that tint stripe all day). When I called them they said 'What is the problem? The glass will work fine'. They are a small business and I was the one who pushed them to hard to ship it to me so I will take responsibility for this mistake. So I have now taken the additional step of ordering 3/16" Lexan Margard and will cut it to the same shape and will tint it like all of the other Lexan Margard windows with the super trick 3M CR90 Crystalline film which will give the windows a very OEM look. Who knows if the Margard will stand up to wipers on the surface - I'll have to be very careful not to drive the car in bad weather. I'll keep the chinese glass just in case) - May 12, 2015
Part 87 (I managed to get the intake system 'final assembled' and get all of the fluids into the engine/trans: the coolant, and I tested the system with electrical water pump; the transmission fluid; the engine break-in oil, and I made up an oil pump drive tool to prime and test the system (using a VW p/n 027115027 oil pump drive gear from a 16V ABA motor, machining off the gears, and then TIG welding on a 1/4" socket); and finally the fuel in the tank and testing of the fuel system. And yes, there were lots of false starts, dripping fluids, and some new injector o-rings are now on order) - May 19, 2015
Part 88 (The past 10 days have involved a lot of electrical parts sourcing and planning as I have come to the realization that it is simply not practical to just wire up the engine ECU and fire up the engine without planning and executing the foundational electrical system before hand. Something as simple as routing a wire thru the firewall requires that the location of the wiring harness be pre-determined and also that any gaskets already be in place (and the gaskets are sometimes hard to source). I also made the tough call to bail on using part of the stock wiring harness and instead will completely rewire the GTI end to end so I have made up a nice flip-down wiring panel under the glove compartment that will hold all of the distribution panels/fuses, and relays. I also determined that a 20AH Lithium Pros Battery would be my power source (Lithium batteries have a very flat discharge curve and can be deep discharged making a 20AH capacity battery equal to a 30AH lead-acid battery and it weighs 7.5lbs vs 30lbs) so I ordered one. I plan on running 1/0 flexible welding wire from the trunk to the wiring panel, passing thru a remote/wireless controlled 150amp disconnect switch and a 200amp current shunt (to allow the ECU to monitor the charge/discharge rate of the battery), then controlling the switched +12V via a traditional 150amp continous duty solenoid which will then feed all of the fuse panels and relays. All mechanical switches will be replaced by ECU/Digital display touch panel controlled virtual switches, including things like the emergency flashers, various lights, seat heats (continously variable heat control by computer) etc. Even the old turn signals and driving lights will be controlled via the virtual switches by feeding the dash/stalk switch outputs to the ECU inputs and then the ECU outputs will drive the 50% duty cycle relay controlled turn signal outputs, etc. - all using the Holley Digital Dash unit (by using the Dominator ECU I have tons of assignable I/O pins so I might as well take advantage of the same technologies used in software controlled cars like the Tesla). I also sourced a Kicker IQ1000.5 1200W RMS amp for the audio system which is all software programmable and streamed to by bluetooth) - May 28, 2015
Part 89 (Major score today! I was wandering around the local automotive parts store looking for some electrical supplies and out of the corner of my eye I spotted what looked like a VW mk1 US spec light bulb holder on the rack of GM connectors. On closer examination I located what looked like all of the major bulb holders for my Rabbit GTI and took them home to verify that indeed these were the correct replacement parts. This makes total sense as the US VW engineers would have had to meet US DOT lighting requirements so why not dive into the local Detroit parts bins and borrow a few things? Here are the part #s:
Front turn signal bulb holders: GM 88860442
Rear side turn signal bulb holders: GM6298892
Rear 2 circuit bulb holders (2 required): GM 12003758
Rear 3 circuit bulb holders (6 required): GM 12003759
All of the bulbs for these holders can be sourced in LED format which is what I have done, with an eye on keeping the same level of brightness as the original bulbs (you have to be careful as most LED replacement bulbs are lower brightness) - June 2, 2015
Part 90 (I got all of the fuse blocks, regular and micro relay blocks arranged on the panel that will mount under the glove box and will drill holes and start to mount everything this weekend. I also got the LED lights mounted in the housings with the new GM bulb holders and tested out their brightness (they modestly exceed the brightness of the OEM bulbs but require a dimmer 47 ohm resistor for the dual brightness settings to match the stock look). There are also a few minor clearancing issues with the LED bulbs that require a bit of work with a dremel to allow them to fit in a few of the holders. Here's the info on the bulbs I used which were ordered from LEDlight.com:
Product ID: 25454
Product Name: S25 27 SMD 5730 10-30V AC-DC
Attributes: Color - Warm White 3000K Base Type - 1156 Single Circuit
Product ID: 25454
Product Name: S25 27 SMD 5730 10-30V AC-DC
Attributes: Color - Warm White 3000K Base Type - 1157 Dual Circuit
Product ID: 45689
Product Name: T10 Wedge 5 Ultra Bright SMD LED Bulb 1.5W W5W 12 VDC T3 1/4
Attributes: T10 Color - Super White
- June 5, 2015
Part 91 (I was tired of smelling raw gas in the garage and did some research on what racers do to safely and properly vent their gas tanks without the loss of fuel vapour and the answer turned out to be a trick invention from a UK company that makes a bi-directional fuel tank vent valve that releases pressure inwardly at 0.05psi (for when the fuel pump is sucking and needs air intake) and outwardly at 0.7psi for when the temperature of the fuel tank as warmed up substantially and excess pressure needs to be released. This keeps the tank vent closed in normal use and nicely eliminates the smell of fuel vapour in the garage. I did also find that the fuel level sender gasket wasn't sealing perfectly so I added some silicon sealant to it and that solved that problem. Finally, I added thin -6AN aircraft crush washers to all of the engine compartment -6AN fuel fittings to ensure that they were absolutely sealed - the problem of sealing AN fuel fittings seems to come from combining fittings from different manufacturers - just a precautionary measure.
I put a ton of time into wiring the ECU harness and installing it into the chassis. I think it will take another 2 weeks to complete all of the chassis/engine/ECU wiring and then it will be time to finally fire up the engine) - June 15, 2015
Part 92 (The fuse/relay panel was finished and installed in the car - now the wiring looms need to be terminated and attached to the relays and fuse blocks. I sourced original AM/FM cassette decks for the car as well: A Blaupunkt Denver SQL26 which looks very close to the OEM cassette deck (does anyone have a hi res photo of the original one?), and a mint condition Concord HPL-130/dBx AM/FM cassette deck (this is the model I installed in my GTI in 1983). I also got more wiring done on the chassis) - June 29, 2015
Part 93 (As part of my engine ECU wiring I had to run the low voltage and high voltage wires next to each other for a short distance so I did a careful job of shielding them fully.
I had been fighting the computer and sensors for the past several days but finally have it running now. Boy, it starts with authority and has a serious exhaust note to it (not really loud at all at idle but when the throttle opens it gets serious in a hurry). With the 288 race cams it will idle roughly at 900rpm but prefers to be closer to 1050rpm for smooth idle. I was expected worse ... seems that the ITBs saved the day.
I had fabricated a hall effect sensor for the crank position 60-2 wheel from a late model mercedes but it turned out to not like the tooth width/depth and would give the computer erratic timing info at anything past 200-300 cranking rpm. I had to go back to the ABA inductive sensor (analog output) that the Holley dominator ECU accepted. Once that was out of the way I got correct timing for the ignition/firing of all plugs, and all other sensors were operational. But then it would fire and immediately die after transitioning from the cranking parameters to the running parameters. Turns out that Holley means zero fuel enrichment when programmed for 100% - I had it set to 'zero' and that means 'kill the fuel injectors'. Go figure. Anyway, I have lots of programming left to do as the AFR learning is limited to modifying the parameters a fixed % beyond the base tables, not learning all of the fuel tables from scratch. My tables aren't close enough yet to allow the engine to run beyond 2000 rpm without leaning out so I will be at it again tomorrow sorting out the tables. It starts nicely now, builds lots of oil pressure, the cooling system programming all seems to work nicely (the electric water pump speeds up and slows down as required, the cooling fans speed up and slow down as well, etc - all really trick/nice to see).
Boy a new engine smells a lot when it first heats up!
I used the brakes and put the trans into 2nd gear and got up to about 40-50% throttle on it up to a little under 5,000rpm to help quickly seat the piston rings and auto-learn the base fuel tables. All went well and now I am going to take a much needed break from the project for a few weeks and go on a family holiday and will then head into the fall with the idea of completing the car and getting it licensed and on the road ...) - July 22, 2015
Part 94 (Tragedy has (almost) struck the ultimate GTI project. Cylinder #2 high mount 30lbs/hr injector failed (this never happens) in the ‘on’ position, filling the engine with fuel when I was doing ECU fuel table learning under load. Potentially serious issue as fuel is not compressible and could result in bent internals. Freak failure. Never seen or heard of this happening before. Not an electrical issue. Simply an injector that decided to die and let the fuel pour out of it. I took the intake system apart, cleaned up and got the fuel completely out, etc.
Did a compression test: 180psi on all 4 cylinders on a cold engine. This is actually a great result given the 288 solid lifter cam with its large valve overlap specs. Will have a new injector tomorrow. Will change the oil and should be back in the game this weekend) - August 6, 2015
Part 95 (After sourcing a new injector, cleaning up the mess from dumping so much fuel into the engine, lubricating the cylinders with Sea-foam cleaner/lube, cleaning and re-installing the O2 sensor and Denso spark plugs, and bolting everything back together there were no more fuel leaks or sticking injector issues.
I put more time into re-scaling the fuel and ignition tables, expanding the area from 70-102kPa MAP where the engine operates with the 288 race cams, tuning the idle IAC parameters, and also tuning the timing around idle and low-rpm part throttle, enabling idle stabilization via timing variation, programming in the acceleration enrichment tables, and otherwise leaning out the fuel table parameters to compensate for the low volumetric efficiency below 5000rpm, and after all of that the engine starts nicely, settles into idle smoothly, and has a very crisp throttle response, which is to be expected of an ITB setup.
Now that this is all done and a lot of the basic A/F ratio fuel table tuning has been done/learning completed, I won't fire the engine again until the wheels are on the ground and the rest of the interior and wiring is basically completed. It has 180psi cold compression on all 4 cylinders and is broken-in enough for me not to worry about idling it.
Now a few comments on the design decisions re. cam selection and other related engine components: We put these cams in at the last minute after previously deciding to build a set of race-ready heads and intake system with mild cams (a combination that pretty much achieves the best of both worlds) and then Josh (the engine builder) and I mused about first seeing what the potential of this engine was with the 288 cams, and then, if it was too much for the street we would swap in 276 or milder cams later on. I will likely also swap in softer sport H&R springs and have Bilstein re-valve the race struts for the same reason: first to demonstrate the full performance envelope of the project car and then bring it down to earth a bit with some de-tuning.
There is a birdie whispering in my ear saying that the 288 cams might actually be streetable simply because the ITBs allow for fairly smooth idle even with very low vacuum and the car is so light relative to the power output (likely 1800lbs and 250hp w/o nitrous) so the lack of low end torque may not be an issue - and it may help soften the throttle response at low rpms that otherwise might be over-the-top with the ITBs. I also have the option of having the nitrous come on below the torque peak at 2500-5000rpm to compensate and then shut off. We have used this trick with big turbo setups to spin up the turbos and cut lag by 70% or more and then shut off the nitrous. The ITBs are a related issue as the throttle response of this setup at low rpm is tremendous and I can only imagine how crisp and aggressive it will feel above 5500rpm when the cams are in their sweet spot. I like a crisp throttle but the problem I have with this engine is that the ITBs are huge (45mm but shaftless so equivalent to 48mm units) so essentially one throttle body can supply all of the engine air needs on its own and when those 4 blades all open together only a few % there is a dramatic increase in air flow. It reminds me of how my old 83 GTI felt when I swapped in a Weber 'Big Throat' TB - it got tiring after a while with the overly sensitive throttle - and that was with a 100hp/2100lbs car. I can only imagine how much more sensitive this project car's throttle response will be and how tiring it may be to have to be so careful with my right foot all of the time. We'll see soon enough ... fingers crossed.
Something else I was worried about was how the exhaust note would sound. I have used multiple race-type resonators stacked end-to-end in street/track cars in the past with great success (quiet yet no loss of top end power - actually building mid-range torque over less muffled exhaust systems) so I used 3 straight-thru resonators on this project car. I will have to get one of my studio big diaphragm mics out and record the sounds for everyone to hear properly. The exhaust is quite mellow with a deep bass but not a lot of high end - which is what I expected to hear. When the throttle is opened up it is quite aggressive sounding but not like the usual rice-rockets on the road these days. I think it will be perfect but I need to get the car out of the garage to hear it properly) - August 9, 2015
Part 96 (I took the glass windscreen and traced the shape onto paper and then transferred it to a 3/16" (6mm) MR10/Marguard Lexan sheet, then cut it out with a jig saw, profiled the edges with a palm sander, and then sent all 8 windows to the auto glass shop for the application of the 3M CR90 Crystalline film (90% visible light transmission, 50% heat rejection). Note: applying film to Lexan is generally not advisable as Lexan absorbs moisture and therefore can re-release moisture when high levels of heat/sunlight hit it, lifting the film (bubbling). And it is also hard to apply the film as the water required to help position the film sucks into the lexan causing it to grab/set pre-maturely. I found an installer that is very good and is willing to give it a try: we hope that the MR10/Margaurd coating on the Lexan will act as a barrier and will make the film application easier plus will reduce the potential for bubbling. I will also be careful to not get the lexan windows wet and then subject them to strong heat/sunlight ...
Once I get the windows back I can install the front windscreen and then mount the dash permanently (after re-coloring) so I can then complete the dash wiring, etc. I started the process of re-coloring the interior plastic parts by attacking the center console over the last 3 days: the console that came with my car was crudely hacked up by the previous owner so I found another console and set about filling and sanding out the imperfections. I started with a good cleaning, then application of 3M plastic filler, then 220/320/400/600 grit dry sanding, then 600/1000/1500 grit wet sanding. I am ready to re-color it tomorrow. I also ordered the correct BA7 and BA9 instrumentation LED bulbs for the gauges) - August 16, 2015
Part 97 (I gathered up all of my various interior components to compare colors and decided that my initial decision to match the back of the seat vinyl color with the Parasol Varibond re-coloring solution was the best option: it is a bit less 'blue' and a bit more 'grey' than some of the plastic console and door card components but it matches the seat fabric perfectly, plus the carpet and I think it is overall a more pleasing color than the 'in your face' blue of some of the other parts (VW wasn't very fussy about matching colors back in the day - it seems that every component had a slightly different color balance to it and so I have to make a judgement call). I have done 2 coats of painting/sanding of the center console and it is starting to come together - one more process of sanding/painting should do it and then I will start to get a production run going for all of the other interior components including the new deck lid carpet which is currently black.
I am also starting to work up a 'for show only' dummy VW GTI dash gauge cluster to place in front of my Holley Digital Dash when the car is parked or being shown - the idea is to have a thin panel that can be placed in front of the digital dash or removed at will ..). - August 18, 2015
Part 98 (I have been prepping the plastic interior parts for re-coloring, plus planning out the addition of 2 more air vents and the design of the new digital instrument cluster. I will not re-color everything until I receive the SEM plastic repair supplies I ordered which will give me the opportunity to re-texture surfaces that I have filled and sanded. I will have to re-setup my sterile painting environment in my garage to avoid dust contamination) - August 24, 2015
Part 99 (With my 288 race cams the idle manifold vacuum is only 30kPa/8" which is far less than the minimum required amount to operate the brake servo, so I have sourced a GM electric vac pump, an adjustable vac switch (so I can adjust the amount of vac 'assist' I want) and a check valve plus I TIG welded up a Tee connector that mounts into the servo unit and provides connections to the other components. I will weld a bracket to the underside of the front strut tower brace to support the unit.
The 3M window film jobber said 'no way' after attempting to apply the CR90 film to the MR10 Lexan windows (grabs too fast) so I mounted the front window without film and found that it curves to shape nicely and looks fantastic (optic quality is superb). I was a bit concerned that 6mm (3/16") Lexan would not conform to the window frame shape as it is fairly stiff. I am using 4mm for the other windows.
I received my plastic repair kit items from SEM that includes a 2 part plastic filler, a 2 part plastic glazing compound, a flexible sandable high build primer, and a texture coating and went to work refinishing the center console and back seat side panels which needed sanding and re-texturing. Once that work was complete and I was happy with the results I also prepared a few other interior parts and sprayed the final color coats all at once (yes I am really happy with the results). I am now ready to tackle the bigger task of re-coloring the front door cards and dash.
I also ordered a Boyo VTM43TCA auto dimming rear view mirror that has a number of advanced features: an integrated backup camera monitor; a wireless grill mounted temperature sensor and a compass, plus hidden touch screen programming features. It is 2" wider and a bit taller than the OEM mirror so I will have to reshape the visors when I re-cover them along with the installation of the new headliner. For safety reasons I like backup cameras - both to protect the car from hidden objects and to avoid driving into things in my garage that are often on the floor.
Finally, I am designing a panel of switches and potentiometers to be hidden inside the ash tray: ignition 'on' switch, start switch, engine kill switch, nitrous enable switch, nitrous purge switch, A/C on switch, A/C temperature pot, and 2 seat heater pots. All of the mini rocker switches have different color LEDs embedded in them so it should look nice and trick when the ash tray is flipped open) - September 10, 2015
Part 100 (The effort to repair, re-texture and re-color all of the various plastic parts (midnight blue and black) continued with vengeance over the past 10 days, with the biggest successes being the completion of the major dash components. I also got deep into the effort to restore the fender flares which need a lot of work. Finally I also received the Danfoss 400W 12V A/C compressor (which translates into 1500BTUs which is only a small fraction of what a crank driven A/C compressor is capable of putting out but should be sufficient for my needs) and I also started to order a few of the other components that will be necessary to complete the whole A/C system) - September 20, 2015
Part 101 (After gluing in the missing chunks plastic, then using SEM plastic filler to fill the extra holes and deep nicks and scratches, and then SEM plastic fine finishing putty, I sprayed the original GTI fender flares/liners with SEM high build flexible primer and sanded them, repeating this process until the surfaces of all of the fenders were smooth and defect free. Then I applied SEM flexible texture coating and then used 400 grit sandpaper to flatten the texture until the VW OEM texture appearance was achieved. I then shot the fenders in Parasol semi-gloss black plastic paint 3 times - they finally look mint again!
I had 2 sets of the rear hatch side shelves - neither set was perfect, each with their cracks and other damage from 3 decades of hard use, so I chose the 2 best examples and started the process of removing the old carpet, gluing in extra supporting plastic material underneath to re-enforce the units, and then used a heat gun to soften the plastic and bend each unit carefully back into correct shape (they warp over the years). Then the process of prepping, filling, sanding and painting using a combination of the SEM plastic repair products, and finally the careful process of measuring & creating a template for the carpet, and then cutting out the carpet, painting it midnight blue, and then gluing it together (after again masking off the non-glue areas). It all worked out nicely in the end but took a lot more time and effort than I had anticipated) - September 30, 2015
Part 102 (I have made more progress designing and building the 12V air conditioning system using 2 Perma-cool 1.5x7x14" oil coolers, 2 12V waterproof fans, and a bunch of custom fittings.
A problem I had when testing the engine was that I had mounted a small K&N crankcase breather filter on the end of the plastic OEM breather vent on the front of the ABA block which was not adequate to keep oil from splashing into the filter and then dripping all over the engine and garage floor. The not-so-simple solution was to design a 1.25" stainless steel vent tube that winds its way around all of the obstacles at the front of the engine to the side where the K&N filter can sit vertically above the engine block - with a slope in the vent tube that allows the oil that gets into the tube to drain back into the block.
I also put a lot of time into sorting out the mounting of the 6.5" Hertz woofers into the door frames and figuring out how to modify the window regulators to avoid an interference, plus got well underway with the hole punching process to create 'grills' in the door cards - plus I solved a problem with old warped particle board support by wetting/steaming/pressing/drying the door cards, etc. ...) - October 9, 2015
Part 103 (I have both of my door cards drying for a week after wetting the particle board and pressing them flat again so I have taken the time to fire up the motor and start the process of fine tuning the software parameters. It turns out that the canned demo parameters for typical American V8 engines are far too rich for a highly sprung 2.1L 4 cylinder like my highly modified VW ABA engine which seems to need very little fuel at startup or idle ....) - October 15, 2015
Part 104 (Over the past week I spent time researching what others have done to program around the needs of individual throttle bodies (ITBs), comparing their work to my own, and there are a number of different approaches that people use: some folks bail on the idea of trying to use the manifold absolute pressure (MAP) sensor as a primary input control to the fuel table and just rely on the throttle position sensor (TPS) called Alpha-N, some elect to use a hybrid approach of MAP and TPS, cutting over at a specific RPM or TPS set-point, but after a lot of study and review of my data logs from prior engine test sessions I decided that with a few changes to my setup I could stick with a pure MAP/speed density fueling strategy. Here's how I have approached things (keeping in mind that I have matched my ITBs with race cams which also add complexity to the tuning challenges as they kill low end vacuum ...).
The closed-loop control (CLC) system in the Holley ECU is very fast and accurate so when the fuel tables or sensors aren't perfect in a particular situation the CLC will almost always fix the problem ...
I realized that one of the things I was fighting was my idle air control (IAC) valve control circuit - when the IAC was open more than 5% to help increase idle RPM, it reduced the MAP sensor's ability to sense the MAP at the throttle bodies - I have a common vacuum plenum that the IAC attaches to at one end and 4 separate -4AN vacuum sense lines running to each ITB - when the IAC opens up it pulls the plenum MAP close to atmospheric, essentially overwhelming the tiny vacuum signals from the ITBs. So I re-calibrated my idle by manually opening up the ITB blades, forcing the IAC to run at 1-3% opening to control the idle when warm, not the prior 12-15% setting. This dropped my warm idle MAP signal from 70-72kPA to 63-65kPA which improves my ability to control fuel flow in and around idle/part throttle. I now have close to 40kPA of MAP range to program with ...
I was also able to move my closed-loop control (CLC) sensitivity factor to the max '5' setting in the ECU, allowing it to nearly instantly correct for any errors in the air-fuel ratio (AFR) being sensed by the wide-band O2 sensor in the exhaust system - this max sensitively setting does not appear to create any instability which is a risk in setting it too high - but I will keep an eye on things in the data logging tables once I get the GTI on the road to see if there are any conditions where I may need to back off on the closed-loop sensitivity. One worry is that I have long, large diameter race headers with the O2 sensor mounted in the collector so there is a time delay from the injection of fuel to the sensing of the AFR ...
I managed to find several happy settings this week: the right IAC 'return to idle' settings - allowing the engine to gently and consistently return to idle smoothly and quickly without over or under-shooting; the right acceleration enrichment (AE vs TPS rate of change) table entries to keep my AFR stable when blipping the throttle - resulting in incredibly quick and satisfying throttle response; and finally my cranking/startup fueling strategy - again, I have continued to lean out all of my fuel tables and now when the engine is warm I only need a tiny fuel prime 'squirt' before cranking and 2.5lbs/hr of cranking fuel, which is pretty much the same as my warm idle fuel setting (which shows how efficient these engines are). And I also found good IAC 'parked' settings to give the cranking engine just enough air when the engine is cold or warm to kick it over cleanly and start without over-revving too high or stumbling before climbing up to the idle rpm set-point.
My fuel tables are now dialed in as close as I need to hit the road and do the rest of the tuning in real-world conditions: my MAP vs RPM fuel tables look quite non-linear as my ITBs and race cams require - the fuel needs are almost flat at low rpm and all MAP settings up to 90kPA, then a steep ramp up of fuel flow up to 101kPA/full throttle - at higher RPM when the ITBs and race cams come into their own, everything transitions to a more linear relationship with MAP signals from 60-101kPA building fuel flow at a more linear rate. Since I can't fully load down the engine on engine stands in my garage, completing these tables will have to wait for the street ...
I found that the Holley ECU doesn't like to try and learn/correct the AFR when the fuel tables are too far off the mark - when-ever I tested the fuel table at a new rpm/MAP range I often had to manually correct (usually lean out) that area of the table before the ECU would jump in and start to correct/learn - this occurred even though I had CLC and learn parameters set to +/-100% offset ranges: if the engine revs to a range where the AFR is way-off the engine will not want to stay there and will hesitate/hunt around for an RPM/MAP point that it likes.) - October 25, 2015
Part 105 (The speaker grills for the door cards were completed successfully, the audio system components are all now together and ready to be installed, the remote mounted Lithium battery was installed and tested with updated battery cables, the final A/C system components arrived and are now ready to be put together and tested out, and most importantly, I got a new Lexan curved cold air intake box made up and tested that looks great under the hood ...) - November 5, 2015
Part 106 (Background: as a young electrical engineer 30 years ago I designed power supplies and battery charging systems for mobile devices ...
I was very excited to be able to use the latest greatest automotive grade Lithium ion ferrous phosphate battery technology from Lithium Pros as they are vasty superior to lead acid batteries in several ways: very flat discharge curve (the battery voltage stays high); high high cranking amps without voltage drop (cranking at 12.8V, not 10-11v); very fast charging (all of the available energy from the alternator is immediately stored); many times greater cycle life; deep discharge capability (you can use all of the capacity without damage); and light weight.
But the negatives are: poor performance in sub-zero temperatures; and a less than ideal match to standard automotive alternators that put out 14.4V when Lithium batteries don't want to be charged at more than 3.4V/cell = 13.6V. On-board battery management systems try to shunt the additional voltage and excess current thru internal discharge resistors and it sort-of works but the ideal situation would be an intelligent computer controlled alternator regulator that can rapidly charge the Lithium battery and then back off ... enter my latest project idea ...
I built a circuit that allows full alternator voltage up to 13.6V and then limits it to 13.8V - it does this under ECU control by monitoring the battery voltage and then spoofing the alternator into thinking that it has reached 14.5V by outputting higher than actual voltage back to the alternator 'sense' wire. It uses a charge pump circuit to get 16v to the op amps, and the PWM output of the ECU to send signals to the circuit to increase or decrease the Vsense line. It works perfectly and now I have a charging system that won't limit the life expectancy of the $1200 battery I have.
And I completed the associated battery charge/discharge ECU monitoring circuit which consists of a 75mV/200A shunt in series with the battery and a bi-directional differential voltage amplifier/monitor that puts out a 0-5V signal to the ECU (2.5V = 0 amps, 0V = 66 amps charging, 5V = 66 amps load) ...
I also received my midnight blue headliner material from SMS - it is a perfect match to the VW OEM fabric and is nicely foam backed ...) - November 17, 2015
Part 107 (I completed the fabrication and installation of the A/C vents in the center of the dash, fabricated the mounts and modified the dash plastic to allow for the Holley digital dash unit, did the re-wiring to install the Lithium battery current monitor and alternator voltage regulation in ECU command, dismantled the car rotisserie, purchased and setup the EZcarlift, took the car out for its first drive down the lane and in the process damaged both the Wilwood brake callipers and VW Snowflake wheels, repaired all of the damage, did a 4 corner weighing of the car (1540lbs, 70/30 weight distribution) and calculated the approx final weight and distribution: 1800lbs and 66/34 distribution). A lot of progress - my back and hands are worn out and need a rest!) - November 28, 2015
Part 108 (I cut the coils to set the correct ride height for the front and rear suspension, plasti-dipped the fresh-cut ends, put in a nylon washer in the top of the front strut bearings under the top nut and washer to take up some slight slack (to avoid the potential for rattling when the suspension is unloaded), confirmed proper ride height after lowering the car onto its wheels, did a basic front wheel alignment, determined that the problem with the steering 'clunk' when changing direction was related to the pinion gear moving up about 0.050" against the pinion gear cover, took apart the steering column, removed the U joints, pulled off the pinion cover, realized that there was really nothing under the cover to positively hold the pinion in place and keep it from moving up and down, machined the pinion cover to accept a friction fit brass shim/bearing surface, machined a matching brass shim of the correct thickness to eliminate the ability for the pinion gear to move vertically (without binding), pressed it into the cover, put the R&P back to together (not easy when the engine and brake servo are in the way), put the steering column back together, adjusted everything, verified that the pinion gear wasn't binding against my new shim but was snug, lowered the car onto its wheels and verified that the direction changing 'clunk' had been successfully eliminated when under load. I am very happy now as the steering is super responsive with the Quaife close-ratio R&P, and that the system has zero play in it and is smooth and very precise now) - December 1, 2015
Part 109 (I had to re-route the rear brake lines to solve an interference fit with the 14" VW Snowflake wheels, plus solve a repeat brake fluid leak from one of the master cylinder to rear proportioning vale lines by making and installing a new metric bubble flare to SAE inverted flare line. After flushing the system again the brakes are solid and there are no more fluid leaks!
I decided to mount the GM brake vacuum servo pump on its rubber vibration isolator mounts to a custom stainless steel bracket that I made up and attached to the rain tray holes that originally held the ignition coil. I ran some tests using an adjustable vacuum switch to prove that the brake pressure could be electronically controlled. I then ordered another GM/Holley MAP sensor so that my engine ECU can be used as a master controller of the brake assist vacuum - using a potentiometer that I can turn as I drive I will be able to adjust the brake pedal pressure at will now.
I also received my digital level and Longacre steering toe measurement plates and did a full front/rear alignment (front: 1/8" toe out, -1.3 degrees camber; rear 1/8" tow in, -1.0 degrees camber) and I installed the 3mm spacers for the front wheels and ordered 15mm spacers for the rear axle/brake assemblies, plus matching 40mm 12.9 grade M10x1.5 Allen bolts. I also ordered new longer wheel lugs (M12x1.5x25 and M12x1.5x30 R13 ball seat) for the VW snowflake wheels and an additional set of matching 60 degree conical seat lugs for my lightweight Enkie Racing RP01 wheels and Hoosier racing slicks) - December 11, 2015
Part 110 (I was hunting down the few remaining fluid leaks and so it was time to investigate why my Mocal Laminova oil to coolant intercooler was leaking oil. I contacted the SEM Laminova engineering firm in Sweden that makes the unit under contract for Mocal and they said 'Where did you get those brackets? They aren't from us and they are mounted incorrectly. The brackets must be positioned outside of the flanges, not on the inside.' Well, Mocal supplied the brackets but they did not fit on the outside as the ID was too small so I assumed that they needed to be sandwiched in-between the flanges and the body. Wrong assumption. So I machined them to fit, and put everything back together, put coolant and oil back into the system, and, fingers crossed, that will solve that leak. So far, so good.
I built a stainless brace/bracket that triangulates the steering column lower mounting point to the brake assembly/vehicle frame and it has removed about 80% of the flex inherent in the OEM design. I also machined a collar for the top of the steering column that keeps it in place and eliminates any up/down movement. I think I am finished 'tuning' the steering system now - I hope that it will be nice and crisp/precise when driving on the road ....
I received my Lella Autosport 15mm rear axle spacers which are very nice indeed. When using them in conjunction with my 3mm wheel spacers it now looks like my front and rear wheel/tire offsets are identical - I still need to drop the vehicle onto the pavement to verify but I am waiting for the proper bolts as the ones which Lella supplied are about 5mm too long (and the nice 40mm long socket head 12.9 grade bolts I sourced were fine thread and unlike the rear rotor mounting bolts which are (m10x1.25mm) fine thread, the axles mount with std pitch (m10x1.5mm thread) bolts. Me bad. New ones on order now ...) - December 25, 2015
Part 111 (For the last few weeks I have been working on the rear wiring and lights, starting by building a new rear wiring harness with all new connectors and LED lights (see prior posts for p/ns), plus I worked on coloring the Hella replacement tail light assemblies to be a hybrid of a US and Euro Spec look to them (I am also building aluminum/carbon fiber bumpers that will be a hybrid of US and Euro Spec look to them - shaped like the US bumpers but scaled a bit smaller and closer to the body). I got the powered radio antenna installed in the back, plus sorted out the backup camera mounting and wiring, although I blew up the camera by connecting it to 12V when it needed 3.3V. I also got the 12.9 grade rear axle mounting bolts installed with the Lella AutoSport 15mm spacers) - January 17, 2015
Part 112 (I finally got to the point where I had all of the parts necessary to assemble and bench test the electrical A/C system. I used low temperature aluminum/copper solder (500 degree F) and I didn't really do a very good job on the receiver/drier connectors as I didn't apply the massive amounts of flux that that particular solder requires - so I had to re-solder a few places and still need to chase down a few remaining leaks (I have ordered Harris Al-Cor brazing wire and will re-do all of the connectors and I may also switch over to flex lines ...). All of the copper compression fittings are leak-free but another set of leaks occurred after 24 hours at the NPT teflon tape fittings as the POE oil in the system actually dissolves teflon tape - so I replaced the white tape with yellow gas spec tape and it seems to hold better (we'll see ...). The system was charged up with R134a refrigerant and it came to life. It will need tuning to bring out its maximum potential: the oil coolers I am currently using as the evaporator and condenser cores aren't very thermally efficient when used in an A/C system and so I will look more into finding small A/C cores that will fit my application, plus I need to determine the ideal R134a charge load - I added too much at one point in my testing and the performance dropped almost to zero (I think the low side pressure should be around 25psi and it was up to 40psi). With a medium-high fan setting I saw about an 8 degree F drop in air temperature coming thru the evaporator and I'd like to see more like 10-15 degrees drop (this compares to commercial systems that are >4x more powerful and can drop the air temperatures from 80+ degrees F to below 50 degrees F).
I thought I should provide some basic automotive A/C background info and relate that to this project: A typical crank/belt driven automotive A/C compressor is capable of 10-20000 BTU/hr output capability. Due to the law of thermodynamics heat/energy removal (a thermal transfer process) isn't a watt for watt 1:1 relationship. e.g 1 watt of energy input into the compressor translates into approx 2 watts of energy removal from the air. For my tiny little Danfoss BD250GH compressor, which draws around 10-15 amps at 12.5V, or up to 200W, it provides up to 400W of energy removal, or around 1300 BTU/hr. I could upgrade my compressor to 2 other available units (http://www.seanhylandmotorsport.com/blog/12-v-air-conditioning-compressor-how-can-you-decide-if-one-is-right-for-you/) that consume 20-31+ amps of power for between 3000-6000 BTU/hr of cooling capacity in a package that is roughly the same weight and size (7-10lbs) as my Danfoss compressor (with easier to manage automotive A/C fittings pre-installed - but the compressors have less complex electronics that can't speed up and down the compressor as energy demands change - you are limited to turning them on/off). Air weighs 0.04Kg/cu-ft and the fan I am testing with is around 150cfm, which means that the mk1 golf with its approx 80cu-ft of interior volume would have its air exchanged every 30 seconds and in that case my little compressor is removing around 3-4 degrees C of temperature from that volume of air. Dry air has a specific heat factor of 1000J/kg-C (in other words, it takes 1000J to raise the temperature of 1 Kg of air 1 degree C and 1W = 1J/s). My fan is moving 150cfm or 2.5cf/s, or .1Kg/s or 100W per 1 degree C of cooling = 300-400W of cooling, so my system is pretty much running as expected. If I slow the fan speed down 70% to an equivalent to a 'low' blower setting I can then expect the air temperature drop to be around 10 degrees C. And that is with a small Danfoss compressor. You have to remember that the sun radiates a huge amount of energy into the car interior while driving and when a car's interior is hot it requires a huge input of cooling to bring the temperature back down, and that is why 3000+ BTU/hr is a better starting point for a 12V electrically powered A/C system. I think I can make my little 1300 BTU/hr system work effectively but I might end up changing to the larger compressor in the end. This is a big science fair project and so I am learning and experimenting along the way. Fun stuff!
I received my p/n 191501639A rear axle bearing dust shields and they fit) - January 24, 2015
Part 113 (My 33 year old plastic front grill was beaten up and needed to be sanded down with 600/1000/2000/3000 grit wet sandpaper, and then masked off and painted with the red GTI edge stripes, plus the GTI badges needed to be color matched. The grill cleaning and sanding went really well, but my initial attempts at using a hard rubber roller to paint on the Parasol red plastic paint were a near complete failure as the paint dried on the roller very quickly (there is a lot of powerful solvent in the paint that evaporates super fast) plus the solvent in the paint which helps bite into the plastic also tends to dissolve the prior layers of paint when disturbed by a roller or brush - but isn't a problem when spray painting. I ended up destroying 2 rear GTI badges before giving up and finding NOS GTI badges on ebay and then masked off and spray painted the red stripe on the grill. That worked out, but the masking was very tricky/time consuming, plus some of the paint found its way under and around the masking so it took another 4-5 hours of wet sanding and touching up the stripe with a fine model spray gun ... in the end it was all worth it as the grill looks awesome now. Plus I successfully hand painted the front GTI badge with the same red paint and then carefully block sanded it down smooth to match the grill stripe (it was a bit off and now everything matches 100%). I am really happy with the look now.
I then took all of my new parts for the electrical A/C system and put them on the prototype system: new #6 A/C barrier hose and fittings for the drier/filter unit, lots of temperature sensors to bench test the system, and more air boxes to fine tune the performance and help squeeze every last drop of performance and efficiency from this system (given that it is a bit marginal re. cooling capacity). In the end the amount of R134a refrigerant charge that provided the best performance was 35psi on the low side with the compressor running at max speed (4,400rpm at 13.5amps/13.3V). This provided close to 7 degrees C of air cooling across the evaporator at an equivalent to a 'low' blower setting in the car and a little over 4 degrees C of air cooling at an equivalent of a 'medium/high' blower setting (150cfm - enough to change the air in the cabin every 30 seconds). The performance #s are solid: 160W of electrical energy providing approx 400W of cooling (1,400BTU/hr). Since I have a small racing alternator I cannot afford more than about 15amps of continuous current draw at idle, so if this proves to be too little cooling the next step up in compressors is closer to 2x in both current draw and cooling, and is also 2x more expensive ($1,200 vs $600). I'll install this system and if it is not sufficient for my summer needs and I am not at the edge of my alternator capacity I might upgrade to a larger compressor .... we'll see - February 8, 2016
Part 114 (I fabricated an aluminum bracket out of 1/8" material using my new sheet metal brake to mount my Hella air horns (the same ones I had on my old GTI back in the day) - they fit perfectly beside the water pump housing. I then mounted the HID high voltage transformers under the radiator area, and also figured out how best to mount the MAP sensor that I will be using to measure and control the brake servo vacuum. I also finished cleaning up the trunk area where I had ground off the wiring metal tabs (that I won't be needing), filling, sanding, priming, base coating and clear coating it all. finally, I got started on the ash tray which required sanding and filling, then texturing and painting before I can fabricate an aluminum panel for the inside of it to mount 6 rocker switches (Ignition on, engine start, engine kill, A/C on, NO2 enable, NO2 purge) and 5 potentiometers (A/C level, Seat Heater 1/2, Brake Servo Vac, blower speed) - February 17, 2016
Part 115 (I ordered and installed some OEM rear license plate mounting h/w and finally mounted my original GTI license plate on the back of the GTI. A milestone!
I managed to cut/punch/nibble/bend an aluminum bracket to mount the 6 switches and 5 pots in the ash tray, plus design and print to a durable label with all of the panel info. It barely fits but it does fit and looks the part (I am happy about how it turned out). I'll have to wire up a 15 circuit Molex connector to it and then from there to the ECU next ...
I found an excellent electric A/C compressor from Boyard in China that is a 2.5x capacity step-up from my Danfoss compressor that I had bench tested. Here are the differences:
Danfoss BD250GH: 2.5cc cylinder volume, 2500-4400rpm, max email@example.comV (162W) to produce approx 350W of cooling (1200BTU/hr - a COP efficiency of 2.1), 11.6lbs with controller, results in a drop in air temperature of around 5 degrees C at mid-range blower fan settings. Variable speed so current consumption can be reduced.
Boyard JVB075Z12 : 7.5cc cylinder volume, 2500-3700rpm, firstname.lastname@example.orgV (340W) to produce approx 850W watts of cooling (2900BTU/hr [higher COP efficiency of 2.5] of cooling at 3300rpm (so at 3700rpm it will produce closer to 3250BTU/hr at 30amps), 16lbs with controller, should result in a temperature drop of closer to 15 degrees C in comparison to the Danfoss unit at 3700rpm.
I am waiting for new A/C connectors as I will switch completely over to #6 and #8 reduced barrier A/C hose and fittings given the larger capacity of this unit. As a variable speed compressor the current draw can also be substantially reduced as required - my ECU will control the compressor speed based on cooling system demands) - March 2, 2016
Part 116 (I got the ash tray control panel wired up, test mounted, and built a wiring harness to connect it to the ECU, then I completed the wiring and installation of all lights in the rear of the car, and then built and installed a front-to-rear wiring harness that runs inside the frame of the car, then I connected the wiring harness into the electrical panel and ECU at the front of the car, and also sorted out all of the dash and stalk wiring components that I will use (a mix of old and new), plus I got fairly far into building the wheel well audio and battery system Lexan mounting solution. Finally, I machined and installed the #6 and #8 A/C fittings onto the new Boyard A/C compressor and then assembled and bench tested the system: was a big improvement over the prior Danfoss compressor, putting out >800W of cooling power (almost 3000BTU/hr), vs. 350W for the Danfoss unit. This translates into an 8-10 degree C temperature drop across the evaporator at a medium to high blower speed setting which will make it an effective A/C solution for outside temperatures of up to 30 degrees C or more, at a typical 15-25amp current draw) - March 27, 2016
Part 117 (The complete audio system was setup and tested (a combination of vintage and state of the art components) - it was a success. The Lithium battery and audio system was then installed in the car while the dash was prepared by fabricating a mounting bracket for the Concord tape deck, plus the ash tray control console stops were fabricated and installed. The A/C system was bench tested for current consumption at different compressor speeds, and another A/C compressor controller was ordered that has a shorter 5s startup delay so I can duty cycle the compressor to achieve even lower cooling capacity. Mounting brackets were fabricated/welded up/painted for the A/C compressor and controller unit and everything was test mounted - again, a success. Finally, the A/C condenser was assembled with water proof fans and was mounted under the car) - April 14, 2016
Part 118 (Major wiring is now complete. Yes, after a lot of work the wiring job is coming to a close. Blame it on my desire for complexity and computer control over all aspects of the car, but it is almost entirely done now - some of the final wiring will have to wait for the rest of the interior to go in, etc.) - May 3, 2016
Part 119 (The final countdown to project completion begins! ... I think I have around 100 hours left to go and a number of those items include things that can be done after road licensing/certification and shakedown testing (putting decals on, finishing my 2/3rd size carbon fiber/aluminum bumpers, some interior trim, etc.).
Over the past 2 weeks I machined up a smaller steering column collar, and installed it along with a new top column bearing assembly and ignition switch, put weatherpack connectors on the seat heaters, sorted out all of the h/w and plastic bits needed t put the seats together (and ordered a few missing parts), got the sunroof sorted out as well by refinishing the parts and ordering several new items (the wind deflector and levers, new cable assemblies), epoxied on quick connect o-ring fittings to all of the A/C components, got the front and rear cameras installed and connected to the rear view mirror, and fabricated a transition air box for the evaporator to blower motor ...) - May 20, 2016
Part 120 (The big day finally arrived today with the completion of the installation, vacuum testing, R134a refrigerant charging, and system performance verification. The system gets nicely cold, frosting up the TXV thermal expansion valve and lines running to the Evaporator, plus the Evaporator itself gets frosty on some of its surfaces. The air temperature drops up to 8 degrees C flowing thru the Evaporator, and I expect that the total air temperature drop will be more than 10 degrees C as the rain tray area gets chilly from all of the cold A/C components there and that has an indirect impact on the air flowing thru that area on its way to the Evaporator. We'll see once the GTI is on the road in June ...) - May 25, 2016
Part 121 (While I was attempting to put the seats together I found out that the recline mechanism on the driver seat was jammed for some reason and it turned out that the upholstery guy (who shall remain unnamed) ruined the mechanism by drilling holes and installing sheet metal screws into the cross tube and shaft inside it - the shaft was jammed/damaged and needed to be replaced. And it turned out after stripping the seats down to see what was going on that the welds from the tube ends to the side frames were broken as well. It was a big job to design and fabricate a full repair but in the end the seat is stronger and straighter than ever and I am very happy with the final result now.
The sunroof system is now installed, complete with new silicon rubber rear drain tubes, new spring retainers, cable/lifters, headliner, and a new wind deflector) - June 7, 2016
Part 122 (Headliner - Wow! This was a much more involved task than I had envisioned. 2 weeks of thrashing and it is finally complete. One of the challenges is getting the foam backed headliner material (from SMS Automotive Fabrics) to be cemented flat, straight, etc. over such a large area, another is all of the sunroof interface issues, and in my particular situation the metal bosses that the sunroof mechanism screws into are lose and require vice-grips to hold from the under side when attaching the mechanism from the top so there is no way to put the sunroof in AFTER the headliner is in, so I had gymnastics getting the headliner flowing correctly into the sunroof opening and then attaching the trim - the video explains it all. In the end it is 100% to my satisfaction - it just took about 20 hours longer than I had budgeted ... The dash is going in starting this weekend ... (I am on a roll now)) - June 24, 2016
Part 123 (The dash is 'in' - minus the speaker wiring and final lower console assembly which will have to wait until the doors and carpet is in - everything fits well and works correctly and I get decent airflow thru my 'custom' centre air vents which is great. I have a small amp remote control dial placed below the ash tray that allows me to quickly adjust things like subwoofer volume and it 'just' fits and looks subtle enough. I now have to rebuild my paint booth this weekend and re-base/clear the front fenders (one of them had a small rust bubble and they both needed more clear coats for final wet sanding), and re-clearing the doors (again, I am not happy with the slight waviness from prior wet sanding so want to get them dead flat), plus I damaged the rear lower valence near the muffler by lowering the car onto my heater which needs fixing ... then I can get the doors assembled and mounted and all of the glass into the car, etc.) - June 29, 2016
Part 124 (I built a temporary paint booth in my garage to re-paint my doors and front fenders as they needed to be 'improved' somewhat - and I am very happy with the results (almost no dust in the air so the painting was clean). I also did some touch-up bodywork/painting on the chassis where there were a few solvent bubbles (thankfully only on the drip rail) plus I repaired the damage to the lower rear valence and fixed one rust blister on the inner lip of one of the rear fenders. While I had the temporary paint booth setup in the garage for the doors and fenders I took advantage of the setup and used it to apply Parasol Varikote vinyl dye to the door cards after masking off the chrome and red striping. Once the doors are polished I can then assemble them ...) - July 4, 2016
Part 125 (The door cards were completed after some bloopers, all the body panels were installed and gapped, fender flairs and spoiler attached, the decal stripes were applied, and the carbon/aluminum custom bumpers were partially completed) - July 17, 2016
Part 126 (I got back from a trip a bit early and managed to complete the front bumper semi-completed - I still want to make custom caps - see video for explanation.) - July 21, 2016
Part 127 (After holidays and such I have managed to get the project somewhat back on the fast track. This last week I finished the carbon/foam/aluminum bumpers, installed all of the lexan panels, mounted and adjusted the gap on the rear hatch/tailgate, mounted the door handles, re-keyed the lock cylinders, rebuilt, painted and mounted the mirrors, and started on the rest of the door assembly work. T minus 40-50 hours max now before licensing it ...) - August 10, 2016
Part 128 (The last 2 weeks were an intense period of battling to put the doors together with the lexan windows and non-OEM windows lifter mechanism, seals, locks, speakers, etc. In the end there was a conflict between the speakers and the lifter mechanism that has caused me to reconsider the design and move towards a mk2 electric lifter mechanism using the hand crank arm as a momentary up/down switch - the video explains why. I am also going to get a local plastics firm to heat bend some Margard lexan to the correct curved shape as the flat lexan sheets don't take the proper shape and are hard to move in the channels. For now the driver window works but the passenger window is fixed - I have the option of simply putting in the OEM glass and the OEM lifter mechanism but I'll try the above approach. The doors look great overall and the sub-woofer ended up working out really well. The latch for the carbon fiber hood had to be re-worked a bit and is now functioning properly. I am T minus 1 week to project completion now ...) - August 22, 2016
Part 129 (33 years to the month, my GTI sat again in my childhood home’s driveway: I took delivery of my original GTI in May of ’83 but it didn’t get licensed until August ’83 (no job, no money, no license …).
I drove about 3 hours in the car in total today - yes it was driven in the rain and got nice and dirty (I took my family and my dad out for rides), shaking out the initial bugs and gremlins. It will be about 1-2 months to get the car behaving the part (fast, fun, safe and semi-civilized). I discovered lots of things that need addressing already: the brakes are a bit mushy and need professional bleeding, the steering alignment also could use a pro setup alignment, there are some squeaks and rattles, the fuel gauge needs calibration, one of the radiator fans is DOA (I don’t think I will need 2 after all so maybe it will just be disabled), for some reason the engine shuts off at 6,000rpm, just as the fun starts, there was a fuel leak when I topped up the tank, the windows don’t roll up properly, it is a bit harsh and noisy, etc - you get the idea ...
The GTI is spending the night at the mechanics and should be certified road worthy tomorrow so it can be fully licensed. I will then have time to run system diagnostics on the crank and cam triggers - I suspect that the old-school analog inductive crank sensor is crapping out and may have to be replaced with an external digital hall effect crank sensor (which requires that a 60-2 tooth wheel be placed between the crank pulley and the crank itself). There may be something else going on but the computer says 'lost sync' in the RPM readout and the ECU goes a bit nuts for a while so ...
The dash final installation went well but the plastic bits rub and squeak against each other when driving on bumpy roads so I will have to start to place some felt tape around various places to get it to quieten down.
The carpet is from stockinteriors.com and is 'mass-backed' meaning that it is a heavier and stiffer carpet than stock and is a pain in the ass to cut and get moulded to the body shape - it took the addition of some stiff foam under the carpet in the front to work out. Now it all looks great.
The seats went in place nicely. The new foam and leather wrapped wheel worked out too.
With fuel in the tank, carpet mats, A/C, stereo, sun-roof, full interior, etc. it scaled in at 1950lbs, with a 66/33 weight distribution. With some of this crap pulled out on race days I'll have an 1800lbs car.
I have 3/4" gaps from the top of the tires to the fenders all-round so ride height is perfect. Suspension is H&R race springs and Bilstein race struts and shocks. A bit stiff but not as bad as I thought it might be. Still, I will also order in some H&R sport springs and try them out) - September 1, 2016
Part 130 (Even though I took the car to a garage with its own race teams who understand the safety benefits of Lexan windows, they were unable to certify the car for road use simply because all windows must have the DOT stamp on them, no exceptions. Turns out it is a big deal. So ...
I am not against putting glass in as it will only add 20lbs or so to the weight of the car, make it quieter, allow me to use 3M CR90 film to keep it cooler without tinting the windows darker, will be much more durable, etc. but there doesn't seem to be any sources of clear replacement mk1 glass in North America available (let me know if you have a source ... or I will be forced to order in from Europe and risk breakage).
I also need to get an externally mounted digital hall effect crank sensor fabricated so that I can rev the engine above 6,000rpm. And since I have 'down time' in front of me, I can get the mk2 electric window lift mechanism sorted out (hope I can make it work), and can also swap in a larger A/C thermal expansion valve as the current one seems to be undersized.
I asked the mechanics to look into why the Quaife R&P steering was a bit stiff when turning to the right and it looks like something inside the unit is binding - maybe I have the pinion set screw too tight? Anyway, with only 3 hours of driving on this R&P I am already starting to hate it: way too much low speed effort, making parking and low speed driving almost dangerous. The mechanics said 'only use that kind of R&P on the track, not on a street car' and I agree now. I'll likely swap in a stock unit.
I am not super happy with the ride quality using the H&R race springs either - the car bounces around, being such a short wheel base car and I think that for general road use and enjoyment I will need to go to the H&R sport springs and maybe also increase ride height 0.25" or so to give this car more suspension travel as it is minimal at the moment.
Such is the path of debugging a completely new and fully custom car ... stay tuned and thank you everyone for your support along the way) - September 3, 2016
Part 131 (I had the GTI in at Weissach (http://www.weissach.com/why-weissach/) who have had an intimate relationship with several of my cars over the years (e.g. they completely re-built my BMW 540i into a Dinan supercharged monster (plus cams, diff, suspension, brakes), they do 911 Ruf conversions, etc.). They pulled my steering Rack & Pinion unit in and out several times and adjusted the pinion pre-load and other tolerances until the steering with the Quaife ratios felt 'just right', flushed and adjusted the brakes so that the car stops NOW, and otherwise double-checked things for me. I put a the 10K resistor in series with the inductive crank sensor, added more shielding and got my full 8,200rpm limit on my motor, plus I changed around some of the electric water pump and radiator fan cooling programming so that the motor temperature was more even, and then set about road testing it. Yes, I still need to put in DOT stamped glass for my final road inspection certificate but that is only a matter of time now.
What was exciting was standing on the throttle and brakes and sawing on the steering wheel and having this car do its thing: and what a performance envelope is emerging now: 115-120% volumetric efficiency above 7,000rpm, an estimated 250hp from 7,500-8,000rpm based on a 0.42 BSFC estimate for this very finely tuned ITB based 16V motor (with full race 288 solid lifter cams, large valves, exhaust, 12:1 CR, no crank accessories to drive, etc.). What is mind blowing is that the motor pulls strongly without burping or farting from 1,500rpm onwards - I can short shift from 1st to 3rd and it will happily pull away without complaining. Oh, I still have to test that 150hp progressive nitrous system ...
I know I initially complained about the Quaife rack & pinion close ratio manual steering box as being 'too tiring' but now that it is adjusted it is beautiful to use and with a bit of planning and finesse low speed operation is fine. And the Bilstein race struts/shocks and H&R race springs, with the hollow rear sway bar (and no front bar) is an excellent combination - no body roll but still compliant. And I think I got the right compromises with the rubber HD strut mounts, the rubber HD side and rear motor mounts, the soft poly front motor mount, the OEM R&P rubber mounts, the poly A-arm bushings, and the Delrin rear trailing arm bushings and custom bearings - rubber is where the harshness can transmit and the poly and Delrin is where it won't and will provide improved precision. Yes, more poly and Delrin would provide an even greater degree of precision but will also create noise and harshness. I think I may have lucked out and found the right balance off the mark ...
I now have at least a month to get the glass in from Europe - maybe I'll find some clear glass in the US but maybe not ...) - September 12, 2016
Part 132 (I sourced a new green tinted front windshield that matches the OEM green tint of the original GTI windows (I have all of the windows from the old car except the windshield) ... but the new one is a glue-in which has 1cm larger dimensions and a black-out mask so it cannot be mounted using the rubber surround that I was using for the Lexan windshield. I have sourced the glue, primer and rubber trim moulding and will install it next week. I am going to use cerium oxide powder and felt disks to polish the old glass side windows to remove the usual wear and tear marks and then will finish installing all of this glass so I can get my final inspection completed and the car licensed.
The Davies Craig electric water pump controller uses a thermistor that they recommend be installed in the return line to the engine block. Wrong move. This resulted in wildly fluctuating cylinder head temperatures as my radiator does an excellent job of cooling the hot fluid before the thermistor reads it so I ripped up the nasty coolant return line plumbing and replaced everything with a clean -20AN stainless line from the oil cooler to the block and then machined the coolant flange on the side of the cylinder head to accept the thermistor - now the cylinder head temperature is stable at 190F +/- 2 degrees at all times and my oil temperature is also lower.
I ran full audio system frequency analysis on all drivers and got the system's frequency response to be flat from 20-20,000Hz and also got the time delays programmed for each driver. The system is almost 1300 watts RMS and is both crisp, clean and crazy loud if required (and the sub-woofer can be turned up to shake the car to death). Frankly, when the engine is running the audio system seems somewhat of a lessor interest, but when the engine is off the audio system is a joy to have - bluetooth streaming, hands-free cellular calls, plus the old-school Concord cassette deck with both Dolby B/C and dBx noise reduction (the tape system with high end metal tapes is pretty much CD quality - but 30+ years old).
Yes, the VW mk2 electric window mechanisms can be successfully adapted to the mk1 - I just did it. You will need p/n VW: 191837402C or 191837462A for the right side, and p/n VW: 191837401C or 191837461A for the left side and I recommend sourcing the mk2 lift channels as well ( p/n VW 867898571) but I did not want to wait so modified the mk1 channels to work) - September 12, 2016
Part 133 (Well, I ended up in the hospital last week with pneumonia after fighting a losing battle with a chest injection/cough for the past 2 months. I am on 'the good drugs' now and they are really helping me get back on my feet. I did low key things on the GTI during this period: I used Cerium Oxide to polish the old set of glass side windows to bring them back to life, and I got my youngest son, Evan, who is 18, to help me glue-in the new front windshield ...) - October 10, 2016
Part 134 (I completed the installation of all of the glass, including the VW mk2 electric window mechanisms and the mk2 lift channels as well, plus I made up some trick custom bi-directional window lift switches that use the old crank arm.
I also swapped out the 1kW A/C TXV for a 2kW unit and the system now pumps more R134a thru the Evaporator at peak compressor speeds, achieving higher cooling efficiency/performance.
I then got the car inspected, certified road worthy, and licensed this week and then went out and drove it around for more than 3 hours - what a joy!
I confirmed a number of basic performance parameters via a series of full throttle acceleration runs and some hard cornering and slaloming dynamic tests: There is practically zero body roll with this suspension system and there is tons of grip but the car is not overly stiff/harsh except on rough concrete expansion joints where the car bounces around with its short wheel base. The estimated 0-60mph time seems around 4s but the tires can't hold the power in 1st gear at any RPM >3,500 so I won't know the true potential until I bolt the slicks on at the track. The computer has provided fuel data which allows me to estimate power and torque #s by using BSFC (for a street engine 0.5lbs/hp-hr of fuel consumption is reasonable but highly tuned race engines such as mine are more efficient at around 0.42lbs/hp-hr). At 0.42 BSFC my engine is putting out 260hp @ 7,250rpm and 200 ft-lbs of torque from 4,500-7,000rpm which is quite something. Obviously this needs to be backed up with dyno pulls, g-meter acceleration data, and track 1/4 mile racing results. I'll have the g-meter acceleration data in a few weeks.
The engine exhaust smells more than I think it should and the oily black soot in the exhaust pipe indicates that the rings have not fully seated yet. I took out the spark plugs and they are absolutely clean looking on the electrical contacts but the metal base rings are a bit oily. I also used a computer/USB microscope to look into the combustion chambers and inspect the pistons, block cylinder walls, and valves - I saw cross-hatching marks still on the cylinder walls which look evenly shiny 360 degrees around, but the edges of the combustion chambers were a little oily looking, with one cylinder actually showing a small drop of oil on the wall, plus the piston crowns looked a little fouled in spots and also a bit wet in spots from oil. The question I now have for engine builders is: how long should it take for my rings to seal (I only have about 4-5 hours of real engine running time where I have been driving the car and less than 10 full throttle acceleration runs to attempt to fully seat these racing rings)? Is there a problem with my rings not seating? I have been using Joe Gibbs Driven Racing Oil 00106 BR 15W-50 Break-In Motor Oil.
After my 3hr drive I realized that my new mini Denso alternator was burned out/DOA. It could have been my ECU control circuit which tricks the alternator into limiting its output voltage to 13.8V (for my LiFePO4 battery) by providing 14.6V into the Vsense input when the output reaches 13.8V. Anyway, I have ordered a PowerMaster 8188 XS Volt 75 Amp mini Denso alternator from Summit Racing with expedited shipping - this unit has fully adjustable output voltage capabilities plus an input that when grounded will reduce the output voltage 1.25V to cut the power draw from the engine by over 50% - saving a few hp during WOT acceleration runs) - October 30, 2016
Part 135 (It is now late fall/early winter in the Pacific North West and the leaves have mostly fallen off the trees and the rain is falling almost every day – it is cold, wet, and the roads are dirty. Driving my GTI in these conditions creates a full hour of post-ride detailing clean-up so it is not worth it to drive unless I really need to. I will likely have to wait a few months before getting a proper chance to complete performance tests …
That said, I was going to use my new G-tech RR performance analyzer to initially bench-mark the power and acceleration of my GTI but it won’t even sync to the GPS satellites in this cloudy weather …
That said I managed to complete a series of hill climbs, completing around 10,000’ of vertical and put in almost 200 miles of aggressive driving on the GTI to help break-in the piston rings/cylinder walls – the exhaust now smells cleaner.
My original alternator had burned out so I purchased the new PowerMaster XS Volt mini denso alternator model 8188 (75amps) but it produced too little idle charging current with my 2:1 pulley ratio, even at 1100rpm engine speed, so I ended up switching to the model 8168 and changed to 2.5:1 ratio pulleys and ended up with over 30amp of charging at idle so that problem is solved. The XS Volt alternators have adjustable output voltage to keep my LiFePO4 battery at a max of 13.8V – it also has an input that allows ECU control over the voltage so I get the best of both worlds – fast charging at idle and a 13.8V limit.
I have been chasing down a few minor oil leaks that are coming from the oil pan seal and possibly the aluminum cover above the pan on the passenger side, plus a very minor leak either from the head gasket at the back next to cyl #4 or ??? plus there has been a minor exhaust header leak around the side of cyl #4 – I have tightened the header up and it is sealing better now but isn’t perfect so I am thinking of trying some Permatex exhaust sealant on the header gasket. I have also ordered some Toyota gasket sealant for the oil pan – to put a thin layer on each side before installing the rubber gasket again …
I cut and installed new window seals for the driver and passenger roll-up windows as I had previously cut them too short and the seals had slight gaps – this time I cut a bit too long which is actually perfect as there is now pressure between the seals and yet they still sit flush.
I think I may have damaged my outer CV joints from my engine testing using the brakes before the car was on the road - having them at an angle during testing ... there is some free play in them now which isn't great so I have ordered some competition axles ...
I cleaned up a pair of mk1 midnight blue visors with dry cleaning fluid and re-painted the edge material and now they are ready for installation.
Finally, I have been trying to resolve an issue of brake pedal ‘feel’ where the first 1-2” of travel are quite a bit softer than the rest of the travel when the pedal firms up nicely. I think I have found the problem: I mixed up the servo from a mk1 16V and the master cylinder from a mk3 non-ABS model. So I have now ordered a new mk3 non-ABS servo and will modify/thread the rod to fit my custom brake pedal assembly. Fingers crossed that the pedal feel will be better after the swap. Oh, the 16V servo was leaking vacuum too which was a bit of a pain …) - November 20, 2016
Part 136 (The new 8168 Powermaster XsVolt alternator is working perfectly - my LiFePO4 battery appreciates it.
I ordered a VW mk3 non-ABS brake servo/booster because I had been using a leaky mk1 servo unit. I experimented with some shims between it and the master cylinder (which is a 22.2mm unit, also a mk3) and initially took up too much of the slack and had the car self braking! But with a single 12mm stainless washer as a shim it reduced pedal travel and now the brakes are feeling pretty good. I have the ability to electronically set the amount of vacuum assist so I have been trying out various settings.
One problem I still have with these much improved brakes (using Wilwood 4 piston calipers and 10.1" disks up front and mk3 disks on the back with a Wilwood proportioning valve) is that even with the valve on full minimum I still get rear lockup first. I am ordering fixed in-line pressure reduction valves to try out (I will leave the adjustable valve in the circuit) plus I am going to order a 25.4mm master cylinder which will reduce pedal travel another 30% (but also increase effort by the same ratio) - ideally I would like to heal and toe with minimal pedal travel and I can simply crank up the vacuum assist if I want a softer effort ....
My old fuel tank level sender unit was crapping out so I ordered a new VDO plastic replacement unit which worked out well but I had to modify the connector to create a right-angle version and now all is well.
It is full-on winter here now with snow and ice on the roads (and salt!) but I managed to get a full sunny dry afternoon this last weekend to do some performance testing. I had acquired a Gtech RR performance analyzer to measure 0-60, 60-0, power, cornering, etc. so I was excited to see what this GTI could do. Well, the Gtech unit had limited measurement accuracy as it seems to have a broken GPS antenna and couldn't get a fix on more than 6 satellites but it did give me basic 0-60mph info: with no off-the-line traction and short shifting into 2nd gear I saw repeated 6.0s times - this is with street tires, dirty conditions and almost freezing temperatures. With good conditions (the track!) I should be able to launch at a high enough RPM to get on the cams (I need 4,000rpm min) to get a high 4s time. The engine is pulling like crazy, putting out 0.6gs of acceleration at 60mph in 2nd gear (my old mustang with its 300hp engine only managed 0.42gs in 2nd gear at 45mph).
I also swapped out my Spal radiator fans for new units as I think I damaged them by running them at a 30% PWM duty cycle which seemed to have fried the brushes - current pulse arcing) - the fans were rattling and sounding horrible. I have now set the minimum duty cycle to 50% which is what Spal's own controller starts at) - December 6, 2016
Part 137 (An important part of any project is the relationship with your vendors who supply all of the components and much of the technical support. In this video I review the key vendors who I relied on:
Ebay and Amazon ...
Josh Arnold (US) - engine builder
Techtonics Turning (US) - major project supporter, providing a ton of components and support
VW Heritage (UK) - specialty VW parts
ESC Tuning (US) - specialty VW parts
Bolt Action (NL) - specialty VW parts
Summit Racing (US) - racing auto parts
SMS Automotive Fabrics (US) - interior fabrics
EAA Engineering (US) - custom fabricated VW parts
ACW Motorsports Plastics (UK) - Lexan windows
BS&S Radiators (Canada) - custom radiators
Bolt Depot (US) - all things fasteners
Mecatechnic (France) - NOS VW parts
Parasol Inc (Canada) - plastic/vinyl paints & dyes
Black Forest Industries (US) - specialty VW parts
Metal Supermarkets (US & Canada) - cut to order metal
Wizards of NOS (UK) - high-end Nitrous components
Bus Depot (US) - aircooled VW parts (that often cross-ref to mk1 parts)
Airhead Parts (US) - same as above
Kinsler Fuel Injection (US) - all things fuel related) - January 2, 2017
Part 138 (I have been fooling around with my braking system, trying to set my rear brake line pressure to the correct level to avoid rear-first lockup conditions without success, and it didn't make any sense to me as I have a Wilwood adjustable proportioning valve in the system. I also wanted to explore ways to continue to improve the responsiveness of the brake pedal - to have it activate as quickly as possible with the minimum brake pedal travel, so I also sourced a 25.4mm master cylinder to swap in replacement of my current 22.2mm MC. This would have the net effect of reducing pedal travel 30% while increasing pedal effort by the same ratio, and since I already prefer running my brake servo vacuum at 50-70% of maximum available vac I can do the swap and maintain the same pedal effort by simply turning up the vacuum (I have an electric vac pump under ECU software control so this is easy to adjust on the fly in the car - I have a panel dial that I can simply turn).
Anyway, I sourced a 3,000psi line pressure gauge with the appropriate adapter fittings to screw into the blanked-off MC ports front/rear and also the bleeder valve ports on the front and rear disk callipers. I first tested the MC and both circuits showed 750psi without servo vac and 1500-1600psi with max vac. Note, I have a custom brake line setup with 1 circuit to the front and another to the rear to accommodate my proportioning valve - similar to many US spec cars.
Next I tested the line pressures at the front callipers and again saw the same 750-1,500psi range. Finally on the rears I saw 500psi at minimum prop valve setting and 1,500psi at full prop valve setting - the surprise was that I realized I had been turning the prop valve in the wrong direction when doing panic brake stop tests.
By reference the factory test settings for VW mk1-mk4 cars is around 1,500psi max for the fronts and 470-510psi for drum rears and closer to 550-700psi for rear disks, depending on the car. The front/rear bias ratio will depend on a lot of factors - the weight bias of the car front/rear, most importantly while under panic braking, and then the type of front and rear callipers or drums - how much fluid volume is required to move the pistons - the piston area x # of pistons will determine the total force applied to the rotors.
In my case I have upgraded to Wilwood 4 piston callipers so the volume of fluid that needs to be moved to get to maximum braking pressure is much higher than for a stock single piston calliper. I didn't do all of the calculations but I think that the 22.2mm MC is a bit small for the Wilwoods and also that the rear bias needs to be fairly low, in the 550psi range.
I'll wait for the ice and snow to melt (Hopefully later in January) and will get back out for some more panic stops with the current 22.2mm MC before swapping it out for the 25.4mm MC) - January 2, 2017
Index of Project web pages
Project Overview, Goals & Initial design specs
Project car initial condition
Bodywork & Paint
Suspension, Wheels, Tires & Braking System
Engine & Transmission
Electrical & Fuel System
VW Vortex Thread on this project
My original 1983 Rabbit GTI (owned 1983-1987)