at speeds over 60 car feels unstable.. feels like it shimmys back and forth.. worse on some roads then others.. thinking its the tires.. but could it be from like a front wheel bearing? steering wheel is pretty solid.. doesnt really shake, but the car feels like its floating back and forth left to right.. any thoughts? Im ready to go buy different brand tires, but dont want to waste the $ if its something other then tires.. alignment was done by champion motorsport,, car is lowered with FVD version PSS9 and it has 19" champion wheels and yokohama tires

 

Could be a lot of things. Did it start feeling this way after the alignment? If so, what were the alignment specs?

Increased negative camber up front tends to make the car "tramline" where the tires will want to drop into a track on the road, such as grooves on asphalt made by heavy trucks. High crown on country roads will also cause it to wander if the left wheels are near the center. You'd be able to feel a bad wheel bearing in the steering wheel.

Jon

 

If the tires are brand new, sometimes it takes about 500 miles to break them in and feel right. When I had Toyo's they felt a bit wandering at first. Also make sure the tire pressures are equal from left to right. I know my car is very sensitive to tire pressure.

 

As Jon said, it could be many things. You need to get/post your corner weight numbers,
to verify you got a decent corner balance when you got your adjustable suspension.
You could check your shock pressures. Two of my shocks (gas, but not bilsteins) had
leaked out, making a bar-stool-with-one short-leg teetering feeling. Are your tires all
worn to about the same depth? I would also get/post your alignment specs.
How long ago was all that work done before you started feeling this?

 

the tires are not new at this time, I noticed the wiggle feel after getting the new brand tires, problem is I had the new tires, alignment and new suspension done all at once, so I dont know if its one or the other.. I do not know my alignment specs, but the car was not corner balanced.. was told by a porsche racing mechanic it is not needed for how I drive and use my car.... my front tires still have a lot of tread life on them, the rears are on the way out..but like I mentioned the car felt this way even when the tires were brand new,, what fast fwd mentioned sounds like the problem.. feels like my car is tracking on the road.. I notice it a lot when I am on the highway...

 

I had a similar feeling in my TT. I had the car aligned by a good shop. Afterwards, the car still exhibited the same feeling. I had my mechanic rebalance the wheels. Still the same thing. He finally found that the front passenger wheel had a slight kink in it. Sent the wheel out & whalla she is good as new.

 

May be a set of bigger anti-roll bar like the set from H&R helps.
My car had problems at high speed with long highway curves.
Since i get the bigger anti-roll bars fitted, the problems were gone!

Phil

 

It's my understanding that if you mess with suspension, have the car lowered....you should have the car corner balanced.......preferrably with you in the drivers seat when being done.

 

I would try to get it re-alignment first. See if everything is spec. Request little more in Toe-in and caster but within spec range. While the tech is there, ask him to pry or wiggle if anything loose. Also request print out.
If alignment is good, now you could hunt for the less.

 

I'm voting alignment.

 

I think I will try a different shop to do the alignment.. will ask if corner balance is needed.. it seems like everyone has a different opinion on if its needed or not for street use..

 

Are you running good tire pressure? 36 front / 44 rear cold

I can feel the car get really loose once the rear tires get below 40 PSI due to sidewall flex. Makes you really think about what all that weight back there really means. Doubt if that would make the car darty on the highway though.

 

need to go to one who familiar with P car.

 

champion motorsport did my alignment.. I would hope they know porsche.. time to look for a new place

 

check tire pressure. I set mine to the 36/44 F/R basically and the car was no longer squirrelly.