A turbocharger is a device driven by exhaust gases that increases engine power by pumping air into the combustion chambers.
Combustion is limited not by the amount of fuel that can be injected but by the amount of air an engine can gulp in to mix with that fuel. Forcing air into an engine’s intake manifold at higher-than-atmospheric pressure allows more fuel to be burned, which results in higher output. The related supercharger also compresses intake air but is driven by a belt, chain or gears. To oversimplify, the turbocharger employs two encased fans mounted on either end of a common shaft. The engine’s exhaust gases are routed through one fan, called the turbine, which rotates the shaft. This, in turn, spins the opposite fan, called the compressor, which compresses the air entering the engine’s intake manifold