The oil burning thing is an issue, I would have had the engine swapped under warranty. If the motor is burning oil, that will affect the performance of the engine (can't have very efficent combustion with oil in the chamber)

As far as the speed at the track, you could have saved yourself 9500 bucks and bought a diablo sport tuner and clicked off mid to low 13's. The tuner allows a more agressive calibration, and it allows you to turn the ESP ALL THE WAY OFF!!! which is a huge issue with the cars (at the drag strip)