With Pzero Neros (comparable with other summer road tires such as Pilot Sport 3, etc) I've found -2.5 on the front and the standard -1.5 at the rear to be perfect at the 'Ring in terms of tire temperatures (outside, middle, inside, checked with temp probe).
This is dependant on the track you go to, if your track of choice has more corners and shorter straights you might need more camber. Also, if you go to a semi slick like R888 or Pilot Sport Cup then you'll need slightly more camber.