nel

Morning all - this thread has made for interesting reading for me because I've just received my PSS9 suspension kit and will start fitting it tonight. One thing that none of you have mentioned is the ride height adjustment where you have a 20 mm range to play with.

So what ride height did you guys choose? I suppose the answer will depend on whether the car is mostly for circuit use or day to day driving on the public roads. The 993tt (at least in european spec) is already lowered by 30 mm compared to the non-turbo versions and seems quite low enough in my judgement.

Cheers

Niels

KOAN

A quick update on my experience with "full stiff" front and rear RS sway bars and PSS9s on 235/285 18 MPSCs. The car became very unstable and understeered and oversteered irratically and was a little difficult to catch. I came as close as I've ever come to totalling my car on my 3rd run, going 105 at the Kink at Road America. I flew off the track to the left (surprise understeer while trying to late apex), about 2 feet off the wall sliding sideways for about 100 yards, before swinging back onto the track, and almost shooting to the other side wall. While I was trying to save it, I was bracing for a huge impact. Thankfully, I was alone at the time. I had a chance to see it on the RA corner cameras. Holy $#&*
Next run group, I changed back to 2/5 stiff front and 2/3 rear RS sway settings and 2F/4R PSS9s, and the car was easily controllable.
The suspension had to be a little softer than normal to compensate for cool MPSCs that were oversized. Now that I've tried this extreme suspension setting, no fool need repeat it!

Chuck

kary993

Chuck, that is an interesting report. Normally when you set up a car you get a characteristic one way or the other but not understeer and oversteer. Are you sure you did not make a mistake that just threw the car into a difficult situation manifesting itself into an unstable appearance? Or, was it just the cold tires? I have seen so many accidents with MPSC when they are not warmed up. I doubt the PSS9's setting had anything really to do with this since I used to set my PSS9's to full stiff on many tracks without any issue.

Just some thoughts....

ca993twin

On my one single track day, I set the PSS-9s to 1 in the rear and 3 on the front. I have the stock (euro turbo) non-adjustable sway bars, and pure street tires. The car was very stable, but tended towards understeer due to the 225 fronts/295 rears, and the particular tires I was running. I really need bigger & better front tires, more front negative camber, and an adjustable rear sway bar. Maybe someday.

Mark in Baltimore

When I had PSS-9's, I would set them to 1/1 (f/r), 1/2 or 2/1, depending on how much understeer or oversteer I wanted for the day or track. I also had RS bars with varied settings and 225/265 MPSC's and have never experienced that high speed understeer. Maybe I wasn't going fast enough. Chuck, do you have adjustable bars? I've never been to RA, but it sounds like it might have been an aerodynamic issue combined with some positive camber in the road...?

KOAN

I think that the instability was mostly due to the stiff adjustment on the sway bars and the cold tires, and the stiff sways could cause the car to hold and break away suddenly front or rear. I've also used my PSS9's full stiff front and rear with no problem, when I use 225/275 17 Victoracers. With my experience that weekend, I softened my PSS9's to give me a little more grip, and get me back in the groove.
By the way Kary, even when it got warm the next day, the Cargraphics oil cooler does a great job of keeping the car cool. Thanks again.

Chuck

kary993

Chuck, glad to hear the cooler is working great in high temperatures. I find the same with mine and wished I had obtained this cooler years ago.

Regarding the break away feeling, I think after reading your additional post, the stiffness of those sway bars was just too much for the tires. I have TRG bars which are abit larger than the RS bars and have moved them to stiff and find the car to be a little more responsive but then the tires are slicks so they can handle the additional load put on them by the bars. You may have clearly found the adhesion limit to the MPSC with that much bar in the car. Glad to hear you did not hit anything!!!

Martin S.

As most of us know, the MPSC just dont stick very well before they are warmed up...generally two laps is the key. Other tires come on more quickly...for that reason, the the ungodly cost of the MPSC tires, I have gone to othere brands: Kumho, Toyo RA-1 and Yokohama A-032 R. I have also gone back to 17" wheels.

Next trip for me...Hoosiers in 18". Kary (see above) let me borrow a set for a 15 minute around Willow Springs...incredible tires, great confidence builders and a significant advantage on the track.

boostid

Question: RE: Hoosiers

Has Hoosier solved the cording problems that were discussed a couple of months ago on their R type tires? Haven't heard anyone talk about it in a while.

Hal
97TT Arena/Cashmere, PSS9s,RS Bars, SRDs