I fitted a Sprint booster to my SRT-6 and it is the best mod every. You would not believe the difference it makes, it is like driving a different car. All the lag has gone and it is so responsive now. The biggest improvement is the way it gets the power down off the mark and really pulls through 1st gear. It makes it feel like you weren't getting full throttle before. Gear changes are a bit swifter too as it is more sensitive.