the car gets very squirmy at high speeds...
anytime i encounter small bumps and dips, the car feels like it gets airborne a little (an inch or so)
im on JIC cross suspension, and have it set at 2 clicks from softest....

the car is aligned to gt2 specs, and sits 3/4" lower than a GT2

do i have have to get new springs becase of the spring rates ?
i know JIC changed their springs rates on the 996...

 

Steve, I'm no expert, but if you really have your car that low, I'm thinking you may have a bump steer issue. Which Porsche shop in your area specializes in suspension set up? They would be able to help you with this. Usually after the experts deal with it, you hear the phrase "it feels like it's on rails". Good luck. BTW, your car is looking great.

 

thanks man
but the problem is actually from the BACK of the car.. .
the rear doesnt feel planted
it feels like its gonna swing around on me ...
im at 43 lbs of air in the rear (cold) ... 19 inch wheels

should i lower it ?

 

for some strange reason my car felt way more planted when i had stock susp with springs on it. When i changed over to sway bars and JIC coilovers... the car felt loosey goosey at higher speeds... dont ask... dont know.. but for top end runs... my car felt amazing on stock... maybe it was the JIC's... maybe the body kti that went in with it... All I know is that I didnt feel confident after 185/mph... where as before.... it wouldnt phase me...

 

You need a suspension guru to drive your car and diagnose it. But at the height you have your car at, you surely have changed the geometry of your suspension and from what you say, you need adjustments.

 

Steve here is some easy stuff You can try. now usually you are supposed to do one thing at a time, but...

- 36/40 psi cold F/R
- Go up 3-clicks in the back and 1 in the front.

The tire pressure will help with compliance as you are over-inflated.
The rear needs more rebound to hold it down. The springs are too strong for the shocks to control on that setting. JIC is notorious for high spring rate but it is because the coil overs are aggressive.

This will help. If you need more then I would see what rates you have and lower them. Let us know how the above helped.

Sam

 

Do you know your ride height measurements? Getting too low in the rear can create bump steer issues there also. The car needs some rake for stability. What are your toe settings, front and rear?

You said suspension is set 2 clicks from softest. Is that front? Rear? both?

 

You need alignment and CORNER BALANCE!

Find someone who specializes in Porsche suspension and pay the money.

 

paddock performance 845 429-4115 ask for Ken he will hook you up!

 

car is 2 clicks from soft all around
its already been aligned and corner balanced ..

i think the springs are just too stiff because thats what my tuner told me aswell ...

im gonna try to lower the tire pressure...

as far as alignment specs
i believe my toe is .03*
my camber up front is 1.3*, and in the rear its 1.5 or 1.6*

 

Let's see how the tire pressure and the stiffer settings work.

 

Steve, My car is set at about the same ride height, and I can drive it with one hand on the steering wheel at well over 160mph, it's that "planted"... You need to get that car to a Porsche Suspension guru and see what's what... You have a better coil-over than I, with more adjustment, so you shouldn't be feeling anything like that...

Mike

 

mikelly
ive taken the car to 202mph and it felt planted as well

im talking about long sweepers
last night i was driving home with a friend in his corvette
and he took this long on ramp at a much higher speed than i

my car feels totally fine in a straight line... and it also feels great going from lane to lane at high speeds.. its the long turns that feel funny

i was racing with a buddy with a gallardo super leggera, and i couldnt keep up in the twisties...


do you think it has anything to do with the fact that my 315 toyo tire is stretches on the rim ?

 

I had a corvette and tracked it before my 996TT...

Alignment, shock settings, as well as swaybar settings could all lend to that feeling. I can tell you that my 1999 Corvette with Z06 suspension upgrades was far more stable than my Porsche before I got it all dialed in and setup properly. The Corvette C5 and C6 platforms are a fair amount wider (remember the Pontiac commercial WIDER IS BETTER?) and that platform makes it more stable feeling out of the box...

Now, with the car setup the way I have it, My car handles everything with ease... Fast sweepers included... You may need to tighten up the rear sway bar to stiffer settings...something is setup wrong.

Mike

 

Do you have the computer alignment specs of your setup you can share?