Bob Rouleau

After a great track event at Calaboge, it was painfully obvious that my RS understeers like mad in slow corners. My car is as delivered - no track alignment. Two other GT3's , one an RS, were there as well, both had track alignments (one more extreme than the other) and all of us had a lot of push. In the slow corners, a well set up 996GT3 would simply walk away while we were busy pushing our front tires sideways!

I made matters worse by softening my rear sway bar one hole figuring that the car would be similar to the 6GT3. Ugh! Mistake!

It will take some fidding with sway bars and alignment to dial out the extreme understeer.

Has anyone tried rotating the front struts to get neg 2.5 camber? I have been told that: a) Sure it gets you neg 2.5 easily; and b) you cannot get less than neg 3.x if you rotate the strut.

If anyone has real experience, please let me know because I want to get the car aligned before the next track event in two weeks.

Best,

Throttlesteerer

Hi Bob,

I agree, understeer is a big issue with the car. The track settings in the manual are not enough to get the problem solved. You have to go 3+ front and 2+ back. Try 3,20 and 2,45 with the sway bars not touched, that worked o.k. for me. Good luck.

Bob Rouleau

Throttle - did you rotate the front struts to get 3 plus? Can you get less than 3 with the struts rotated?

Unitah

I rotated the front struts. That gives you an automatic -2.0 degress negative camber in the front (not over 3). I then shimmed to get -2.75 front and -2.5 rear. I also put 1/8" toe OUT in the front and 1/4" toe IN in the rear. Maxed out castor in front. Front sway bar one notch soft of full stiff, rear sway bar on full stiff. Car had very very very minimal understeer, it was pretty close to neutral. I think going to -3.0 front would eliminate the remaining push.

Throttlesteerer

Yes, they are rotated. You can also do 2+ like that. You will also need some spacers.
3+ sounds like a lot, but it needs it...

Bob Rouleau

Thanks guys!

Apex Late

Bob,

I had -3 in front and -2.9 in the rear this weekend. It was NOT the right set up.

Apex Late

Unitah,

I did your set up with the increased camber. The only thing that I didn't do was toe out. I ran 0 toe to try to save the tires. The set-up was not good with the 0 toe. How hard did you push the car to experience the minimal understeer? I'm not trying to be an *** or suggest that you are not driving hard. I'm simply trying to determine if that is the problem with my set up. My car had maximum understeer and 1/8 toe out seems like a minor change at this point.

I also lowered the car as we disucssed in previous posts.

doc2s

a suggestion would be running less camber in the rear with -3deg. in the front. what was the rear toe set to?

Apex Late

Toe in 10 minutes

Bob Rouleau

Apex Late - yours was handling better than mine! Trail brake the snot out of the car - (I thought I was driving a vette for a while).

Push like a cow and use lift throttle get the car to nose back in.

Use throttle to provoke oversteer to get the nose pointed where I wanted to go.

Abuse my tires.

Was yoour ten mins of toe total or per wheel?

Unitah

Apex Late,
Not a problem at all, why would I think you were being an ***?
Anyway, I'd say I drove at about 9/10ths for the event. I was certainly not at 10/10ths as it was my first event in the new car and I wasn't in the mood for any infield farming or worse, hahaha. In terms of my driving style (as that has a lot to do with how the car feels), I am very smooth and slow at the controls. I don't jerk the car into the corner or "toss" it as some do. The suspension is settled and neutral on turn in. The understeer occured much more on slower corners with almost nothing on the fast sweepers. So, the understeer I am feeling may be a function of the differential, narrow front tires, or suspension. I suspect all of the above to some degree or another. This is why I feel by upping the front camber just a tad, it'll decrease the understeer just a hint more without inducing any high speed corner instability (I think). I may be off base, I'm just not sure yet. Eitherway, my car is having a "Watkins Glen" alignment done in the next week or two, so, I'll report my finding after returning from the Glen the 1st week in June.
As far as the toe OUT in the front goes, it will make the car turn in a lot sharper. As for tire wear, I don't think it'll adversly effect it that much, do you? If it does, oh well, what am I gonna do. THe car feels so MUCH BETTER with toe out in the front, it is well worth it. The toe IN in the rear will keep the *** stable in high speed sweepers.

Apex Late

Actually it may have been my vette driving experience that let me lap as quickly as I did without finding the grass. I actually thought the drifting experience that I gained at the end was the most fun

Total toe was ten mins.

Unitah

Just curious...

I was told that total toe measurements were not as important as toe per side. When I quoted you 1/8" toe out in front and 1/4" toe in in the rear, that was per side, NOT TOTAL. What do you guys think? Isn't toe per side more important then total?

Thanks...

supercup

Motorsport setting for my 997 Cup car are:

Basic settings for Michelin slick tyres (as delivered)
Front axle Rear axle Left/right Left/right
Ride height 77 mm 115 mm
Camber - 4° - 4°
Toe setting(total) 0´ + 34´
Anti-roll bar 75° 45°
Main spring 100 - 60 - 260 120 - 60 - 260
Helper spring 75 - 60 - 43 60 - 60 - 40

The sway bars on the Cup are blade type - but for reference 90 degrees is full soft and 0 degrees is full stiff. So you can see the front bar is fairly soft and the rear bar is 1/2 way.

I found the toe setting front and rear on my 996 Cup and my 996 GT2 and GT3's was 0 - 10' total (0-5' per side) in the front and 34' - 40' total (17' - 20' per side). Caster in all cases needed to be in stock setting.

With stock tires it would seem like -3 degrees would be a good start with 0' of front toe and 34' of rear toe, stock caster, with front bar 1 off full soft and the rear bar in the middle (or if only 4 holes, 1 off full stiff). Ride height will play a roll as well.

I am interested to hear what you guys try and what seems to work.

JCM