sorry for the incomplete response:

Alignment: no issues that I know of that are detremental other than tire wear. I do believe that alot of the conering capability that I am feeling is due to the new alignment / camber settings. We will see onh tire wear. My RS is @ -2.3front -2.0 rear and I get about 3500 mi on the factory cups driving it as intended. We run the cup car with fullRSR suspension @ -3.0- 3.5 +/-, but don't consider tire life.
This is the advantage of changing the control arms to the split / shim motorsport type.

 

I'll be replacing my TA springs w/ PSS and was also told that corner balance is not worth it unless you're tracking.

 

Bob,

Thanks for the VERY helpful replies. The data you posted will come in handy for me next week when my car goes in. From my experience with the GT2, I know exactly what you mean as far as steering/handling feel and the trade-offs.

"Lowering the roll center" just means you are dropping the ride height? You are not changing the front suspension's pivot point or anything like that right?

So stock Turbo control arm allows for negative camber change up to a certain point (-2?), and the motorsport control arm is needed for more aggressive change?

 

I'm not sure on max camber w/ stock control arms, I thought ECLOU posted some #s arount -1.8?

Yes, just refering to lowering car roll center by lowering the entire car (lowering the primary inertial axis, that at which the car wants to rotate about). On our cup car we did relocate suspesnion pivots, using a complete subframe and wheel carrier assembly from the RSR , then bodywork to cobver the wheels, etc. UGH. Crazy expensive and not reccomended, but it works.

 

Sounds very promising. I am interested in your evaluation of and adjustment to the suspension so please keep the reports coming.

It would be quite an accomplishment if your modded Turbo could match the RS's track performance; keep me updated on that too!

 

Chris let us know how you like it? I am debating whether I should drop $5k for suspension (including labor, sway bars, suspension parts)? Your opinion might make it or brake it for me.

 

Hi Ermanno, hope all is well. I will let you know when it gets done.

 

Hello Bob,

I asked about ride heights in the other thread because I had noticed that yours are now matching, actually even lower, than those of the GT2.

A (still active) member of the 996 Turbo forum, KPV, used PSS9 and had much difficulty when he tried to duplicate GT2 numbers on his Turbo. From the data posted below , it seems he attempted a very large drop of 158mm - 113mm = 45mm in front. I believe the problem is that with that big of a drop, he was riding on the PSS9's internal bump stop, and there might have been some harmful suspension geometric changes as well. (Anyone corrects me if I am wrong.)
https://www.6speedonline.com/forums/...ad.php?t=10493

996 Data

• USA Turbo
  Front 148mm to 168mm
  Rear 148mm to 168mm
• ROW Turbo
  Front 128mm to 148mm
  Rear 138mm to 158mm
• GT2
  Front 108mm to 118mm
  Rear 133mm to 143mm

What came out of the thread was that for 996 Turbo and PSS9, a duplicate of 996 GT2 ride heights is not a good idea.

My questions are mainly for academic interest since a. I don't plan to drop my car more than 20mm and b. Sounds like there are multiple other components in your car's suspension being changed and you have a "car builder" -- grin, I love that phrase -- so I am certain you & he would diagnose any potential problem already.

I wonder how the 997 GT2 ride heights compare to stock 997 Turbo? Is the difference as large as in the 996 gen?

I had a GT2 next to my car a few weeks ago and did measure mid fender heights as best I could under the circumstance. To my surprise, the difference is not that significant so perhaps that way of measurement is not accurate.