Billman250

I'd check the pressure with another gauge, be sure they are exact. Be sure the tires are the same. Be sure a front rim and rear rim have not been switched. Had an s2k in here Saturday with switched wheels. Even though the back does not fit the front, it has been proven by morons that it can in fact be put on the front.

This car is famous for the exact condition you described when the rear tires are a few psi different.

pepperinyoureye

My car did the same thing ,got an alignment and its been perfectly fine ever since.

cdelena

That is a good indication of a different rolling diameter of the rear tires, often caused by a difference in inflation or mismatched tires.

X4DLuvOfSpeedX

My S did the same thing recently and everything checked out:

-OEM tires
-Correct mounting and balancing
-Even pressure
-Even wear
-Alignment done by the best shop in town
-Stock suspension and later aftermarket coilovers, both in good condition

Still pulled to the right under acceleration (both before and after alignment and coilovers). It turned out to be a bad tire. I found out when the right rear tire was shreded to pieces (there was NO sidewall left!) driving 40 mph. Replaced with new tires and car drives straight as an arrow.

EDIT: Hmmm... I just noticed that you also installed new tires, so scratch that. Unless one of them was bad from factory. What kind of tires are they?

5SAY307

If it pulls to one side all the time its more likely that the front alignment is off or the front or the rear tire pressure.

If you have a aftermarket front swaybar, maybe its not installed with swaybar collar or the collar might have shifted during a hard corning, U-turn or spin out.
If the swaybar is shifted to one side, your suspension will be tweaked.

If it pulls to one side on power or coming out of a corner, it could be the rear end alignment is off.

MikeyCB

To the left, to the left? For days I've been dying to make a Beyonce reference. I'm sorry. Resume diagnosis.

Pitcru

Car is STOCK. New tires are Hankook K106. Tires are balanced fine but I am getting close to taking them back so they can recheck anyway. Tire pressure is set to stock 32psi all the way around. Alignment was done to factory specs whatever they may be. Still has the problem.

Pitcru

Ubetit

Bad belts in a tire can cause this although i think you had this with both sets of tires.

Boofster

I just installed 255 RE050App in the rear while leaving the stock 215 RE050 in the front (no wear). Before, I had my 245 RE050's in the back and the car felt perfect with no pulling or any issues at all (had alignment a while back).

The new tires were pulling in their own direction at first which I was told was normal until the tread breaks in. It's a little better now but I get the same thing as the OP, the car pulls to the left when accelerating and to the right when letting off the gas. Pressures are the same, checked many times. Install and balance was done at one of the best shops in town. I have no idea what's up. I hate the feel as it does not inspire as much confidence in the handling as before, even though I should have more grip with the wider rears.

Pitcru

PROBLEM FOUND AND FIXED. I had everything checked again, alignment, air pressure, suspension etc. I changed out my new tires for a different new set. Problem is gone. Tire dealer had never seen this before. I guess the combo of tire design and stagger doesn't meet with the cars approval. Don't get Hankook K106 tires for your S2K. They were a good tire otherwise for the limited time I had them. I even did an autocross event on them. All I had to pay was the $100.00 difference between tire brands. I switched to Toyo's.

Pitcru