On a side note, many people prefer a turbo over a supercharger due to this disadvantage. The downside of superchargers is also their defining characteristic. Due to the crankshaft that drives them, they must take away some of the engine's horsepower. A supercharger can consume as much as 20% of an engine's total power output. However, the supercharger can generate as much as 45% additional horsepower.
A turbo charger is basically an exhaust gas driven air compressor and can be best understood if it is divided into its two basic parts, the exhaust gas driven turbine and its housing, and the air compressor and its housing. Each of them perform different functions, but they are joined together at the hip via a common shaft, the function of one impacts the function of the other.
In turbocharged engines, the combustion air is already pre-compressed before being supplied to the engine. The engine aspirates the same volume of air, but due to the higher pressure, more air mass is supplied into the combustion chamber. Consequently, more fuel can be burnt, so that the engine's power output increases related to the same speed and swept volume.
An engine makes power by burning fuel. The more air the engine can get through it, the more fuel it can burn, and the more power it can make. A supercharger pushes more air into the engine.
http://auto.howstuffworks.com/supercharg...
