youll know more once you get your first slip. trial and error.
try clutch dump on last yellow and asses reaction time, if you reaction time is high then next time try on the second to last yellow.
i managed to sus my wagon down to a .065\'s
not much of a diff but it all adds up
also i found tyre pressure change helped i was getting consistent times with heaps of wheel spin.
dropped 5psi out and dropped my time by around half a second and lost most of the wheel spin but with still a touch because i like my gearbox
antilag also helped ;D