A lot of racers run a two step ignition system. This system cuts the ignition to the cylinders at random, after the engine exceeds a certain RPM. Its basically a rev-limiter. The driver can set the low-side RPM of the two-step, to be his launch rpm, the high side is usually the engines red line.
Once you activate the two step, the driver floors the throttle while staging and he won't have to worry about over-revving the engine at the line. Once you release the two-step, the engine is basically unleashed with the throttle wide open. You can recognize a two-step by the uneven pop-pop-pop- of the motor and the sparks are unburnt fuel in the exhaust.