Two things Don..One is the weather, which does change a lot around here from about 11-2 on race day. Part of that being the wind, which is ALWAYS an issue at Infineon, usually a head wind and it WILL affect your ET. How much only time and laps will tell. Secondly would be you being consistent with that you do in regards to temp control with the car. Making sure the car is at the same coolant temp, and oil temps on each of the runs, this gets harder in later rounds but you need to know how it affects the car. All this is even harder with a dual purpose car, but knowing what will happen as the car gets warmer is the key. Cars will pick up or loose ET depending on how warm/cold fluids in the car are. Also the tune up will be affected by this.

Oh yeah I know where you can get a great car..Works well, always consistent