for street driving, anywhere from 30 to 40psi depending on what kinda ride you want. 32-34psi seems to be the sweet spot for most 225/45/17's that are driven on the street.

I run my KD's at 34psi cold on the street

 

on my car, 34psi all around on the street. On the track I put more in the rear to help rotation.

I would start at 32psi all around and see how it feels on your car.