ITB VW GTI wheel lifting question

[Ned Stevens]

At what point is lifting the inside r. wheel considered excessive? I realize that it is inherent to the handling that the wheel will lift, but is 6'' too high - 10'' too high- 12" There must be some limit, and if there is, I would need stiffer springs- have been told that it lifts as high as 12" from those behind me. At present am running- 350# frt - 400# rear- 29mm r. bar- bilstein sport shocks all around w/ hoosier 205's. If I go with heavier springs - what rate springs can my shocks handle? Thanks for any input, NED

[TimM ITB]

You might think about calling one of the VW "specialists" that are very tuned into IT racing. I am in New England and I use Shine Racing Service - they can steer you in the right direction with which springs to run with specific shocks - and that way you'll be able to get the best handling package possible. Dick Shine and crew know their stuff!

Good luck!

Tim Mullen
# 86 ITB

[JamesB]

Bilstien sports per bilstien can handle up to 400# or so. Above that you need to revalve them to be efficient. I am running 550 front and 350 rear with a BSI big rear bar (I think its a 29mm solid.) And I still lift between 4-10" according to those behind me. Its just what front wheel drives do.

Talk to shine, hes setup other cars, I think I might go up in spring rate later, but I am not playing with that till I can get the driver to 10/10ths.

[Knestis]

For the sake of comparison, on the MkIII we are running 500F/700R with the "big" Shine bar AND a 1.25OD/.25 wall tubular Speedway Engineering bar on the back. No front bar at all and I'm shopping for 800# rear springs. We're on revalved KONIs.

We're still taking all of the weight off of the inside rear wheel but it's sure not way up in the air like it once was...

http://it2.evaluand.com/gti/images/teetersm.jpg

(that's back in SSC configuration)

K

[JamesB]

You sure about that? I wish the camera didnt go dead at VIR, you where lifting just as high at VIR.

[Knestis]

Well, you'd be better placed to tell me, James. I'm just going by trackside input. How high and where?

I'm actually NOT hugely worried about the wheel being off the ground, if we can get the last of the pushiness dialed out. It's kind of funny how we make a change, it feels way better, then I get used to it and think it's handling like some Chevroldsmobuicadipontilac POS... :)

K

[JamesB]

Well at VIR your rear was just as high in turn 1, you would lift in Oaktree and bobble in hogpen. The biggest difference on P2 is that your inside front does not extend as far as P1 did. Seeing your car and then mine from outside video at VIR they look about the same in corners.

[mgyip]

http://it2.evaluand.com/gti/images/teetersm.jpg[/b]

I remember seeing that at VIR and inspecting your DOOR HANDLES for scratches!!

Ideally, all 4 tyres should be in contact with the pavement but in order to obtain this, the front springs would be so stiff that the front would just plow. I'm running relatively soft springs on my ITA Golf - 450F, 500R and get a bit of rear wheel lift but nothing much over 3" at the absolute max (or at least that's what I've seen in photos). However the rear wheel lifts very regularly and consistently and doesn't appear to be detrimental to handling so I'm not rushing out to "fix" the problem.

[msogren]

You might try toeing the rear out about 8mm per side. Carquest has shims. This and maybe 500 rear springs and 600 fronts.Thie will reduce the push a lot. Give it a try.
The closer the rear tire is too the ground the better the camber and castor stays in the front. The high rear tire way over loads the outer front. When you get it closer to the ground, less than 4 in, you'l go faster. Another reason why the Jetta goes better, it keeps it very near the pavement, IMHO
MM

[Bill Miller]

I've found that w/ a Mk I chassis, heavier front/lighter rear springs w/ larger rear bars works pretty well. I ran 650F/450R w/ 2 rear bars on my old ITB Rabbit GTI, and was able to keep the rear pretty flat. I never got it to stop lifting the rear wheel, but the car was very neutral to loose. I ran revalved Bilstein Group I's up front and stock Sports in the rear. I know the Honda/Acura folks use heavier rear/lighter front, similar to what Kirk and Matt have talked about, but from my experience the Mk I chassis works better the other way.

[mgyip]

Another reason why the Jetta goes better, it keeps it very near the pavement, IMHO[/b]

Is this b/c of the additional weight behind the rear wheels? (Read: the trunk) We have an ITB Jetta Coupe that races locally and I am surprised at how flat it turns compared to my GTi.

I'm fuzzy on what does and doesn't work on alignments, especially rear alignments - what is the advantage of toe-out in the rear? I'm assuming that it helps to rotate the rear instead of pushing the front but can't quite grasp the concept (yes, I'm simple-minded, that's why I race a VW).

[JamesB]

From what I uderstand toe out in the rear is helpfull as the cornering load of the car flexest the rear beam pickup of the car. So its sort of planning for the toe in that you get. I have to double check my alignment sheet, but I think the car came with -1.5 camber and some tow out shimmed into the rear of the car.

My car is nutral/oversteer as its setup right now. The only time it pushes is when I overdrive turn 5.

[msogren]

Correct onthe Jetta. It has some ass to hold it down.
The next time you check your aligment, jack up the rear wheel about 8in and start measuring :)
The rear toe just helps it turn it some by running the rear tire track out side of the front tire, thus reducing the dynamic load on the front tire. it also has some destabilising affects by working the rear tires against themselves. the slower the tracks with steady sweepers get the best results. the tires scrub off some speed with lots of toe out. I run as much tire pressure and camber as I can hang on to to reduce the scrub .
Dont run this at pocano or daytona or more than 12mm total toe out inthe rain. it wont go straight well but will turn very consistant. It is surprising how a little bit of toe helps, IMHO. MM
if you look at "rear steer" posting the A2 has different bushings.
My A1 Rocco had 350fr# and 275# rear. we put the soft springs in for rain and went just as fast in the dry, so they stayed. The rabbit needs about 100# more each end tho due to the altitude . 6in higher. MM