Hitting the ESP Off button raises the intervention limit for the ESP, and turns TCS off. TCS will cut power in order to stop wheelspin, which is what you don't want for tracking.
@ CarolinaBeach, as far as I know it's either on or off for TCS. I never have any problems spinning my tires during auto-cross launches. Are you sure it's not wheel hop instead?
For the best launch on stock or Stage I, go a little lower about 2500RPM or so, and be VERY gentle with the throttle - our early torque peak causes tons of issues launching.