I am planning on going to Laguna Seca on Dec27th.
I am currently running PSS9's with Michelin Pilot Sports.

Currently on hard acceleration, I notice a lot of "bounce" which I THINK may be bump steer?

My car does not feel "planted" and I am not sure how to fix that. It kind of feels jumpy.

I do not have any aftermarket sway or drop links either. Car has been aligned but i was thinking about taking it back and having it realligned to adjust camber/toe.

What specs should i take to the alignment guy? He does a lot of high end cars and I want my car to feel stable and planted for a track day.

 

Is the bounce in the front end or the rear?

 

Pretty sure rear?
The whole car just bounces left to right at 3rd gear and up hard acceleration.

 

Hmmm, I don't believe I understand that feeling or have experienced it. At least not a left to right bounce but it sounds like a damper issue. I don't know that an alignment will fix that. But you always want the best alignment you can get for the track.

I think F1crazydriver (Enrique) will be at that event, he should be able to help you sort it out and he's a very good driver and instructor.

 

Under normal driving car seems fine.
At high speeds it feels unstable, almost like springs are just too bouncy and it causes car to bounce uncontrollably at hard acceleration above 90mph is what is seems like.
I think it happens right after I shift from 2nd to 3rd gear.
Almost seems like the gear change triggers the car bouncing and then when I let off gas it settles down once car slows down to about 70mph.

 

Is it kind of a slow wallowing bounce from side to side? That could be the lift caused by the front axle. That could be an aero problem, or could be an alignment problem (most likely uneven toe values).

Does the steering wheel try to turn itself?

 

No, not slow. It bounces fast. Almost like a preloaded sprung pressure is there somewhere.
It's a almost violent left right throwing feeling. Like the car is throwing itself to one side and when I attempt to correct it causes a continuous left right rocking of the entire car.

 

Ok so it's not an up and down bounce like if you were going over a bumpy road, but a side to side kind of jolt?


If that is the case your toe settings are off. I've had this happen before and it happened just as you described (above 90 or so MPH and jolting back and forth) The problem is that the toe on the front and back of the car are pulling in different directions forcing the car to try and dart in one direction. General causes are potholes that can knock your alignment out of whack or running over something that bumps the suspension abruptly.

You need a really good alignment and that should rectify the problem. It's the toe settings more than anything though causing the problem.

 

As for your general alignment what tires are you running? Is your car primarily street? How important is tire wear longevity (IE how many miles do you want out of your tires)?

 

It is primarily a street car. So a good in-between setting for tire alignment would be good.

 

I would search this section as there are bound to be some good opinions on that. I personally have never driven with more of a street setup. I don't think you can get much negative camber with your setup now anyways unless you have camber plates. I would crank the front up as far as it will go with the stock upper mounts. It shouldn't be too far for the tires. As for the rear I have no clue.


Good luck.

 

I know exactly what your problem is. First the PSS9's are too lightly sprung for the turbo on track. I know, I originally had them on my car before I upgraded to Motons with a stiffer spring package. PSS9's are good for the street but can't control the turbo's weight on track.

Second, the stock sway bars are too soft for the track, that is why you are getting the side to side motion. Get some adjustable sways and get them adjusted to your liking and you can eliminate the problem. I experienced the exact same thing before I upgraded and dialed them in. Now my car is on rails at the track.

To clarify, I also upgraded all the control arms, steer arms and dog bones, and had a track alignment and corner balance done too. The turbo can be made into an excellent track weapon but needs upgrades to handle it's weight at speed. Good luck.

Since you are now tracking, don't forget to upgrade your brake fluid to SRF or Motul otherwise you may boil your stock fluid and have too little brakes at a bad time.

 

Which specs for toe should I be aiming for? When I went in there last time, he said he close to gt2 specs without going so far as my tires wearing too quickly.

What should I tell him this time?

He said that if the car had issues, he would re-align for free

 

First of all, check to see what your rebound and compression settings are at.. If the Car is bouncing around, you may have way too little rebound or compression damping.

Second.. For the track, you need an aggressive alignment.. IF you want to have the Car work on both track AND street, I would try these settings (which are WAAAAY less agressive than a proper track only setup)..

toe OUT at the front of 1/16th (Car will turn in better)
Toe IN at the rear of 1/16th (Car will be more stable under braking, as the rear wheels spread under braking.. toe in will make them straighter under braking)

Front Camber -2.0, or as close as you can get
Rear Camber -1.5.. This will give the Car more balance front to rear and allow the front end to turn in better and give you less understeer.

Ride height... You want a very slight rake with the rear being higher than the front by 1/2" or so.

Swaybars... You want your front as soft as possible (better bite and grip)... in the rear, you want to be two settings off full hard. (this depends on your swaybars.. If you only have 3 holes, your front should still be at the softest setting, but your rear should be at the hardest.. If you have 5 holes, front full soft, rear two holes from full stiff).

In terms of compression and rebound.. Laguna is fairly smooth, so crank your compression down to 2-3 from full hard in the front and rear.. Set your rebound at 3-4 from full hard.

If you want to see what my settings are for my GT2 for Laguna, here you go: Also a video of the correct "Porsche" line around Laguna.

See post # 65:
https://www.6speedonline.com/forums/...ml#post2891031

Video:

http://www.youtube.com/watch?v=XK6zhvTEbAM

 

Make sure get that toe issue fixed first. There is nothing like your car trying to make a left turn at WOT going over 100 mph. Mine tried it and Road Atlanta which is much like Laguna, not very forgiving.

If he aligns it, and it's still swerving all over the road, tell him he needs to do it better. I had a guy try to fix my car at the track with smart strings and it didn't work, car still going every which way.

You should not have to buy anything for your car to go in a straight line over 100mph.