95ONE

Then your springs are clearly shot. Absolutely. a stiffer front sway bar will help, as long as you plan on changing the rear. An adjustable anything is great to set balance.

M758

A stiffer front sway bar can reduce understeer on very softly sprung cars. I you can reduce the body roll then you can keep the front tire more straight when cornering thus improving the shape of the contact patch. This extra grip can override the more common effect of adding understeer from the increase front spring rate.

shiners780

The problem as I see it with Norm just adding a larger sway is that he is asking the sway bar to do what the spring is intended to do. Sway bars are for fine tuning, not for holding up the car. If the tires are rubbing the top of the fender liners then the springs need upgrading.

A couple problems that I could foresee are 1) balljoints binding from too much suspension travel, and 2) additional forces on the sway bar inner mounting points could cause them to crack.

If you wanna play, you gotta play. Cheaping out when tracking your car is just asking for trouble.

I came away from a track day yesterday at Watkins Glen with a real bad taste in my mouth from people doing stupid things, two incidents of which came real close to wrecking me...too damn close.

I apologize in advance if I sound harsh or patronizing, but please make sure your car is track worthy before putting yourself and others at risk. Not saying you are, but just to think long and hard about what you are doing.

M758

In an ideal world yes.

However that "big sway" bar is just a stock Turbo S sway bar so it effect (both positive and negative) are minimal.

shiners780

Well, I think in any world the concept of utilizing a suspension component to perform what a different suspension component is designed to do is wrong.

I will however agree that adding a larger sway may not give the desired outcome. In fact, when I first purchased my '88 951 (same car as Norm's), I wanted to see how it would perform mechanically before converting it into a track car. I took it to the track bone stock and original. The only thing I had upgraded was the sways to Welt 28F/22R, just because I had them from my old car. Even with the bigger sways, the stock springs with 94k miles on them just weren't up to the task and I had the tires rub exactly as Norm has described.

Now, I went hog wild on upgrading the suspension. Norm doesn't have to spend what I did, but a few track days worth of registration fees would cover a nice upgraded suspension setup and make his track days safer and more fun while improving his cars' handling.

M758

I to feel that springs are to be used for dealing with dive and roll and sway bars are for tuning. However that applies to track only cars. If you have street car and want to improve it for the track, but still keep it nice on street you have to start making compromises. Doing just sway bars is one of those compromises.

95ONE

I don't think there's a big compromise in this situation. I've seen good Welt 250#Springs for around $50 used here.

M758

Don't even start with 250 welts and what compromises they require.
$50 springs that cost you $700...

95ONE

????? Is there another thread I can look up for this?
Well. In any event. Springs are cheap.

Blueman33

i doubt porsche designed any car to have the wheels rubbing in any set of circumstances.

shot springs might put the car in a position of the maximum travel of a good spring under load, but the car wasn't designed for the tires to rub.

if tires are rubbing there is a problem besides springs or sway bars.

i am one of the least technically sophisticated posters on this board, but common sense says something is wrong.

M758

well,
new front springs..
Might as well put in new front shocks while you are in there.
Then you really needt to balance that with bigger t-bars
If you do t-bars you should do bushings too while you are inthere.
Then you might as well do rear shocks too to balance things out.

This is how a $50 set of springs costs $700 easy.

95ONE

Oh... thats what you're saying. Of course!!!
But his line of thinking was to cure it with a sway bar that's too stiff for the rest of the car. - but the sway probably won' fix it. Why not get a set of springs that might be too stiff also, but might actually fix his problem. Better of two evils. - It would be nice to get a better description of why/how the tire is rubbing. But hitting tops of wheel wells does speak volumes.

Funny thing though. I don't even know if he's reading these. Haven't seen him post much here on his own thread! Sometimes I have to admit, I like to hear myself talk. ; )

95ONE

Mabe look at the engine mounts and see if he bought ones that lower the engine any? Replace with stock?

M758

The 26.8 mm sway bar is stock for a turbo S and hardly "too stiff" for non-S 951. You are correct in that it probably won't cure the problem mostly because it is really too soft.

Norm Swanberg

Thanks for the input. You convinced me that adding a little negative camber in the front would not be enough to eliminate understeer caused by the stiffer front sway bar. I have ordered a Weltmeister 22mm adjustable bar for the rear. I think you saved me from some lousy track time with understeer.

I agree that a car needs to be safe on the track as well as the highway. I purchased a KLA front sway bar support kit along with the Delrin bushing set for the inside. That should allow the inner sway bar mounting points to take some additional stress.

I did not consider possible ball joint/control arm problems. I looked at them closely and do not see any signs of damage. The control arms only have about 5,000 miles since new (not rebuilt). Two sets of Koni race snubbers have been added, as suggested in the Performance Products catalogue. I plan to add to these to increase the bottoming protection. I think it would be best to hit bottom before tires rub, regardless of the springs. Hitting bottom often or hard would not be acceptable.

As M758 says this would be a compromise. I consider a not too hard ride a plus. I don't think it would be unsafe to give it a try, with the planned changes. I did not rub very often and some of the time I had passengers on the track. The car does not look to me like it is sagging.

You are probably right that I will decide new springs are also needed. If I had added stiffer front springs and front sway bars while doing nothing to the back, I would have had lots of understeer. Buying used springs does not sound too interesting. I have used springs. If I get new springs I will know what I am getting. I would not want the stiffest springs available and stock height seems best. I have no idea what the rating of the stock springs was when they were new. Weltmeister makes 220 Lb stock height springs. How do these compare with mine when new? Is this a reasonable choice? Any suggestions?
Thanks,
Norm