Car swaying over 80?
 

hi,
i just bought this FD and on the way home, it swayed, like at the drag strip at the top end. like it had rear wheel steering. if i did a lane change, the rear would follow that direction even though the front stopped going in that direction.

i think it has to do with the rear mickey thompson ET street radials. they are like 26 inches tall but the fronts are like 24 inches tall. is that normal with different height tires?

here's my new ride:
http://www.ponycars.net/rx7.htm

thanks!

no answers here since i dont have any experience with street radials. but damn that is a nice car probably my favorite non factory paint. not agreeing with what powers it but damn that is a beautiful car....

Try taking a look at the toe control bushings and lower trailing arm bushings.

I'm not familiar with driving on drag radials.

how much did you get it for?

Yes, check the bushings and alignment. But driving on M/T Streets is going to feel like that somewhat. Put some proper street tires on the car and go get an alignment.

its was the kaaz rear locking and unlocking as i was on and off the gas.

anyone think about tire pressure?

My old boss used to complain about that with his '03 Mach 1. He'd drive to work on ET Streets the day after going to the track, and whether his pressure was up or down (whether he had inflated them to proper street pressure), he'd always complain about the rear end swaying and not wanting to follow the front. It's probably the wrinkle wall tires making you sway. like someone said a couple of posts ago, put proper street tires on, see if that helps, and then get an alignment/check the bushings.

I once put a new tire on the rear of my FD. The other tire in the rear had only 10,000 miles on it. When I would accelerate even slightly, or turn a bit, I would get the condition you describe. I put a second new tire on the rear and the problem went away. The only thing I could come up with is that even a slight difference in circumference between the two tires was picked by the torsen differential and produced the unwelcome steering effect.
My suggestion is to play with the rear tires.....check pressures...see if there's any measurable difference...put on a different set of rear tires....etc....and see if it cures the problem.

thanks guys.
32 psi in the rear.
i read TWO articles from sport compact magazine that said the kaaz causes the sway. its torque sensing, so when i'm one and off the gas, it changes the lockup (which wheel gets locked up) and that in turn causes the sway. no with more miles on the kaaz unit, it does this less. the clutches are getting worn in better. as long as i'm on the gas, this isn't an issue :-)

i haven't really found the quality and accuracy of the articles in sport compact car to always be correct.

if i had to guess, i would say that the toe settings on the rear is off and you need a 4wheel alignment.

with all four same tires, 245-45-16 a032r's, its stable now. did 140 at pocono last weekend. all is good :)

The diff shouldn't have any noticable effect in a straight line, unless your tires are noticably different diameters. I doubt the diff is the cause of your problem.

Starting with the simplest possible explanation, get your alignment checked. Toe-out in the rear will make the car feel unstable.

-Max

thanks max but ....