Engines are simply an air pump. The more air you can get in and the more exhaust you can move out, the more power you can make. Superchargers are one way of packing more air into an engine. Superchargers or blowers as they are sometimes called have been around for a long time and are still currently being used on some production vehicles. There have been many different types of superchargers made but I will focus on the two most popular versions. One being called positive displacement or roots type and are generally referred to as blowers. These are the style most used on muscle cars due to the ease of setup on a v-8 with a carburetor. They are also widely used on drag cars for street and professional racing. Some of these cars make insane horsepower in the thousands. The blower has an advantage, because it compresses air even at very low speed it also creates alot of torque. This gives the engine very good response and power from idle up. That is why drag racers like them so much, they are very predictable from launch and have almost no lag time.
Blowers are capable of making great amounts of torque, unfortunately the are not very efficient and tend to build alot heat, consume alot of power to turn thus don’t make as much power in the higher rpm ranges. The other popular type of supercharger is a centrifugal type. It is far more effiecient than a blower and has the capability to build alot more boost due to increased efficiency and thus less heat being generated in the intake. The centrifugal type supercharger is alot more common for fuel injected engines. They generally bolt on to the engine like an alternator and use tubes to guide the air into the intake. Superchargers are setup like a turbo in their basic design. They suck air in through the center hole and spin very high rpms (50,000+) to throw the air out radially using curved vanes and compress the air. The supercharger is normally driven by a belt drive using a gearing setup to get the desired high rpm needed to compress the air. One of the problems with them, is that they do not create boost imeadiately because they are dependent on engine rpm to increase to compress the air well. Alot of people like the fact that an intercooler can be placed in line to cool the intake temperatures. The cooler the intake air means less chance of the engine detonating and blowing up. Another added value is that the boost can be increased due to the cooler temperatures. Due to the efficiency of the supercharger the fuel mileage and peak power can both be very impressive. Most sport compact cars use this technology.