Antilag system

In internal combustion engines with turbochargers, an anti-lag system (ALS) is a method of reducing turbo lag in racing or performance applications. It works by retarding ignition timing and adding extra fuel (and sometimes air) to balance an inherent loss in combustion efficiency with increased pressure at the turbine. The excess fuel/air mixture escapes through the exhaust valves and combusts in the hot exhaust manifold, spooling the turbocharger and creating higher usable pressure.