Car Still Scraping on Hard Right Hand Turns - Please Help

[bento]

okay,
so my car is still scraping on hard right hand turns.
the car was recently refurbished with new bilstein hds in the front with turbo tie rods, etc. the car has stock torsion bars and sway bars and fikse 17 x7.5 w/ a 205 in the front.

the first part of the chronicle can be found at
http://forums.pelicanparts.com/showthread.php?s=&threadid=82579

i took the collective advice of the pelican crew and rolled the left front fender lip almost all the way around the wheel well. the car stopped scraping at speeds that were attainable on the street, but at the most recent auto-x put on by my local pca region, the car was still scraping. it wasn't doing it initially due to the slow speeds of the rain soaked course, but as it dried out, the problem came back again.

i asked my mechanic about it and he essentially said that i should get a bigger torsion bar in the front in order to negate some of the roll. of course, this would necessitate torsion bars front and rear. a fellow pelican member dtfastbear runs bilstein sports on his car without any modification and doesnt' have this problem, what's going on here? what could be the root of the problem, i'm going crazy over here having dropped a good chunk of change only to not be able to auto-x my car.

thanks for all the help.

david benett

[dtfastbear]

Hey Dave,

You are right that I also run the sports and that I don't have the scraping problem, but I run 15x7 front wheels with 225/50 Kumhos.

Unless I'm mistaken, you are running 17inch Fikse wheels. Is this correct? Your offset or simply the outer diameter difference could be enough to make your situation drastically different from mine.

That being said, when I do run my 17x8 Fikse wheels (235/40 Pilot) on the street, I don't have any scraping problems. And, I run the car *pretty* hard on those street tires occasionally

Other than the Bilstein sports, the suspension is stock - torsion bars and swaybars are all stock and have 160k miles on them.

Also, I just had the car lowered and it STILL doesn't scrape. I'm not just saying that to show off, either

Do you know WHERE within the wheel well you are scraping? I'd recommend putting shoe polish or something like that in all the suspect places, recreating the problem and then going from there. If the inside of the tire is scraping on the inside of the fender well, a small wheel spacer may be what you need. If the tire is indeed scraping on the fender lip, the remedies would be different (different wheel offset required?)

Dean

[bento]

okay, so i coat the whole inside of the fender lip with white shoe polish and then try to recreate the phenomenon? i'll try it for certain but it doesn't make any sense to me that i had previously auto-xd my car a bunch with ageing boges and the same rim and tire package and never had this problem.

it keeps on going and going and going

if the tire is hitting the fender lip on load when i turn right, then what do i have to do? torsion bars? new offset of rim?
something is wrong here.

db

[makaio]

Dang Dean, after watching you turn a 2:17 @ Thunderhill, I thought your suspension was way tricked out. You can drive my friend

[dtfastbear]

Thanks for the kind words, Matt. My wife and I just installed the shocks ourselves and got the lowering/alignment done by S-Car-Go and WOW! What a difference!

I can't even imagine what it would be like to go with their "starter" suspension package that upgrade torsion bars, sway bars, changes shock mounting points - the whole nine yards. THEN we could lay down some seriously fast times...

Dean

[dtfastbear]

Dave,

Back to your problem -- I think the first order of business has to be to find EXACTLY where the rubbing is occuring. I'm not convinced that you can just assume that it is fender lip to outer tire edge contact. It just might be somewhere else. For instance, I can see when I have my wheels off that when I turn the steering wheel all the way to one side, the back-inner edge of my tire rubs against the inner fender well, but I've never heard it or considered it a problem.

I'm suggesting that before you spend any more money or time changing things, isolate the contact point, then engineer the solution from there. I think your mechanic needs to take a lesson in problem resolution procedures - guessing at solutions based on the symptoms isn't the best way. Find the PROBLEM, then recommend solutions.

Are you going to the Stable? I hate to say it, but they took a similar approach to solving what turned out to be head-temp-sensor problem for me a couple years ago. They kept guessing at solutions - each one costing me time and money - without actually finding what was wrong.

I'm busy this week/weekend because we're moving, but I might be able to get together with you in the near future if you need another set of hands/eyes.

Dean

[bento]

dean, i might take you up on that offer.
i am in fact going to the stable and in no way do i want to rip them (i truly think that they are a very good shop) but i think that their emphasis definitely lies in the maintenance of stock vehicles and they aren't super stoked to deal with a crazed Porsche junky like myself.

db

[don911]

db,
I had a similar problem on my 87 except my right tire was rubbing on hard, sweeping right turns at the autox. Do you have a strut tower brace? If not, I suspect that your front struts are spreading apart. I installed the weltmeister tower brace and it solved my rubbing problem. It also will give you more responsive turn in. In my opinion, the weltmeister is the best one to install because it bolts the brace to the strut towers and has a similar effect as monoballs. It was the best <$200 I've spent so far.

That's my guess. I agree with Dean and you should find out more about exactly where it is rubbing, etc....

Good luck,

[mikequig]

So says the PCA Club Racing rules and I always obey the rules. My 75' 911 prepared "F" car rubs the outside of the driver's side tire for the first few good hard laps on a new or newly relocated to that side tire. The fender is fully rolled, I run a strut tower brace, and as much (2.5 degrees) negative camber as we can get without hitting the shocks. I run 225/50 16's. The Hoosiers rub a bit more than the Kumhos (because they are wider) but it does not matter as some rubbing is allowed and it does not take the tire down to an unsafe level of rubber before the rubbing subsides.

The thing to remember is that these are basically hand-built cars and not all of them are made the same. Some clearances are different and no one cared at the time since no one thought we would be running these big of tires at 50 treadwear or less on 23/31 torsion bar setups w/ the 22mm sways that we are all accustomed to dressing them in. That was then and this is now. If it doesn't rub your tire down to the cord - go with it - the smoke will intimidate the opposition.

-Mike

[skinnerd]

I agree with Dean...
find where it's rubbing first, then decide how to fix that particular problem.
I've found a number of rubbing issues like this by turning the steering wheel in small increments, jumping out to see where both front tires were close to bodywork (if at all), and then continue to turn the steering wheel a little more and have another look. Do this in both directions as far as the wheel will turn. In addition, have you looked closely at the tire itself? Where on the tire do you see rubbing?

Not sure if this helps much? Lots of times this can be a trial and error process. It must work as I have 17x10 Fikses on the rear and 17x8.5 Fikses on the front of my RS replica (not with RSR flares, but just the RS flares in the rear).

I'm sure you can get this to work with a little more effort.
Good luck, and do take Dean up on his offer. Sometimes you might need a second set of hands pushing down on the front fenders to find the rubbing.