I started at 17psi then went down 1 psi per run, best 60ft was at 14 psi, I went down to 12psi but my 60ft got worse, more likely my technique than the tyre pressure though..
Alot of my issues has to do with being consistant, trying to get my launch RPM, clutch slip, tyre pressures the same to get some usefull information is fairly tricky, with a heap more seat time and playing around with the settings should help me whittle my times down a bit by bit.
Thanks, Mark