I am running 245 front and 255 rear Dunlop Direzza Z2 Starspecs and start cold at 28psi front and 29psi rear. Play with it a little bit as the day goes on. If I feel like I am getting a bit too much understeer I may back the front tires off 1-2 psi in later sessions. It also depends on your preference in terms of the car's handling characteristics and the track you are at.