[Headracer]

Anti-lag as used in WRC cars to launch is a system whereby small amounts of fuel are injected and detonated in the exhaust system between the exhaust ports and the turbo. It requires absurdly precise tuning to work correctly and even then is quite hard on the exhaust/turbo system, hence why it isn't common on road cars. As for brake boosting (or left foot braking while on the accelerator), I've never seen anyone use it from a stop. All of the times I've seen it used have been while moving, so the brakes are just providing an additional load on the engine. The clutch stays fully engaged. I don't think it would work too well on a launch, hence why all the ORSCA guys run modified automatics so they can use this exact technique.