Took my 2013 GT with Brembo package to the track yesterday. The car was wearing 26x11.5x15 et streets mounted on some stock mustang tri spokes.

Notice when going down the track the car was very hard to keep straight. The psi was at 18 warm, and this was not my first time on slicks. Ran this same wheel tire combo on my 03 mach 1 at 13 psi with no problem.

So my question is, is this normal on these cars as far as the sway in the rear? Anyone else notice this when running slicks? Anyone have any suggestions on a cure for this little problem of mine. Thanks

 

try lowering the tire pressure,this aint your Mach One.

 

Doesn't lowering your psi make the slick even less stable?

 

lowering rear pressure typically will make the rear stick better. But at some point you will get to low and that's bad news.(break a bead or excessive shoulder roll for example)

 

I assume you mean ET Street bias ply slicks, not the ET Street Radials. Skinnies or stock wheels and tires on the front?

 

Oh yeah that would cause some squirrely issues right there mixing bias ply and radial tires especially in an even less than ideal radial in the front and bias ply in the rear.