When in a race (normally from a roll) The operator of a "boosted" (turbocharged) car does a tricky maneuver involving applying brakes then adding in throttle to add more brake smoothly to eventually cause the engine to load up spooling the turbine creating boost/power while maintaining a constant rpm/speed so that when the driver lets off the brakes the car takes off like a bullet.
The car on the left brake boosted on that race.... didn't you hear the turbo spooling before they went?
Brake boosting
Brake boosting
by Tw34kd November 20, 2009