Since the invention of the internal combustion engine, automotive engineers, speed junkies and race car designers have been searching for ways to boost its power. One way to add power is to build a bigger engine. But bigger engines, which weigh more, cost more to build and maintain, are not always better. Another way to add power is to make a normal-sized engine more efficient. You can accomplish this by forcing more air into the combustion chamber. More air means more fuel can be added, and more fuel means a bigger explosion and greater horsepower. Adding a supercharger is a great way to achieve forced air induction.
A supercharger is any device that pressurises the air intake to above atmospheric pressure. Both superchargers and turbochargers do this. In fact, the term turbocharger is a shortened version of turbo-supercharger, its official name. The difference between the two devices is their source of energy. Turbochargers are powered by exhaust gases driving a turbine. Superchargers are powered mechanically by a belt or chain drive connected to the engine's crankshaft. Superchargers increase intake by compressing air above atmospheric pressure without creating a vacuum. This forces more air into the engine, providing a boost. With the additional air, more fuel can be added to the charge, and the power of the engine is increased. Supercharging adds an average of 46% more horsepower and 31% more torque. Unlike turbochargers, which use the exhaust gases created by combustion to power the compressor, superchargers draw their power directly from the crankshaft.