Mark 4 VW 1.8T GTi Build - RallyCross - MF Class

5 speed transmission mounted, and the engine starts to go in. We were able to keep the Audi TT downpipe, instead of having to buy the custom one for this application; that is only built by one company, and costs over $500.00. This also allows us a nice smooth bend, and the ability to run the TT catalytic converter with the O2 sensor bung. At the slip on clamps, I am going to run a 45 or 90 degree adapter, and run a straight pipe to exit just in front of the passenger rear tire.

Engine installed, and shifter hooked up and adjusted. Fired it and ran for a few seconds. Now to reprogram the cluster to the TT's ECU, and program out all of the emissions parts and bits we are removing.



Edited 1 time(s). Last edit at 12/29/2016 10:38AM by DanielSL.

I don't think I've ever seen a Volkswagen anything with an EGR valve.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Correction: I meant emissions, and I was just typing too fast, after a long day.

Easier is to just get the ECU immo defeated. Local guy does it for 40 bucks for me

Stephen, that is what I mean by reprogramming it. We did the immobiliser defeat today. Got it running good enough, so we can install the APR Stage I tune, and start doing the programming part, of each piece of emissions equipment/lines/hoses, that we can remove to clean up the engine bay as much as possible.
Got underneath the car with a tape and a protractor, and realized there is no way I am exiting the exhaust out of the passenger side like I wanted. So against my better judgment, I am going to follow the stock exhaust path, and cut it short, with a 90 degree exit just in front of the drivers side rear wheel. There are just too many fuel lines on the passenger side, that the exhaust pipe would be directly under.



Edited 1 time(s). Last edit at 12/29/2016 03:13PM by DanielSL.

After playing with weights, and tire sizes, we finished setting the ride height. Took out the Jetta VR6 springs, and installed Golf R32 springs at the suggestion of the shop owner. Between the VR6 and the AWD components of the R32, the springs are designed to handle 50-60 lbs more load than the standard Jetta VR6 springs.
Settings are now at 28 1/4" to bottom of fender lip front, and 27 1/4" to the bottom of the fender lip rear. Once the front end is re-assembled, we are looking at adding 60-75 pounds directly to the nose of the car, so it should be darned close to perfectly even once everything settles in.
Once the spring choice was finalized; I took off the 205 DMacks, and set the car to all 16/65/15 Michelins, as these are the smaller tires. As the suggestion by all was to run narrow tires on this car, I am going to run the Michelins all season, and use the DMacks just as alternates. Once the Michelins are worn too far to use, I will switch out to the brand new 185 DMacks. Might as well use up the older, used tires while learning how to drive this thing.



Edited 1 time(s). Last edit at 12/29/2016 03:26PM by DanielSL.

I wanted to post some photos of the lower control arm differences, which made me choose to swap over the entire Audi lower sub-frame. The first photo is the stamped steel LCA's on the Mk. 4 VW's.
The following photos are of the cast units from the Audi TT.

Hi Daniel,
Interesting build you have going here.

Maybe you know already, but just a quick mention that the left rear tire is mounted backwards. This will probably make no difference for you but just so you know.

Pic

Thanks, Clint. Bad, sponsor, bad! I didn't even notice that. I picked up 13 wheels/tires in one batch from the shop. I am going to have to check every one of them now, as the kid doing the mounting must not have paid very good attention. Aarrgghh!!!!

Edit:

Looking at the first photo on this page, when I had the directional spares mounted, at least it looks like those two are mounted correctly.



Edited 1 time(s). Last edit at 12/29/2016 03:55PM by DanielSL.

Quote
DanielSL
Thanks, Clint. Bad, sponsor, bad! I didn't even notice that. I picked up 13 wheels/tires in one batch from the shop. I am going to have to check every one of them now, as the kid doing the mounting must not have paid very good attention. Aarrgghh!!!!

Hey, at least it's a left tire!

Yeah! I have 4 ZE80's, and 3 ZE90's. So I put the matched set of ZE80's on the car, and kept the 90's for spares. 1 left, and 2 rights, which made sense to me, as I am more likely to blow a bead or dismount a tire on the passengers side, from what I saw at the RallyCross events last season that I was able to attend.
Everyone always misjudged entry, and blew apart their PS tires. Only one DS, that I remember popping its bead, all season.

The 80's should last you quite a while.

You can determine this for yourself in testing, but I don't think you'll find any difference between lefts and rights if you get in a jam for tires. Especially on the rear. It's more about the construction of the carcass and the tread block for your application than the direction the tread block may or may not be pointing. So don't be afraid to mix them up around the car if you need to.

I never noticed a real difference running lefts on rights. I was advised early on that running them inside-out, however, is a really bad idea unless you are a fan of rapid wear. So the directionality is nowhere near as important as the asymmetry.

---

Pete Remner
Cleveland, Ohio

1984 RX-7 (rallycross thing)
1978
Silence is golden, but duct tape is silver.

Thanks for the good information, guys.

Anyone have basic alignment ideas for front wheel drive in a RallyCross specification?

On the front, I was thinking 0.25 total toe-in, and as much negative camber as I can get, to start out with. Probably 1-2 degrees positive caster. Rear axle set at 0 toe, and about -1 degree camber, if I can get it out of the stock adjustments.