Racing Superchargers

Since the invention of an engine, engineers, race car builders and automotive enthusiasts throughout the globe have been looking for ways to boost its horsepower without increasing its size. One of these ways is installing a supercharger. It is a forced induction device that is mounted to an engine and is spun by the crankshaft with the help of a belt or chain. The spinning of the crankshaft drives the compressor inside the supercharger, which forces air into the combustion chamber. The faster the engine runs, the more air is forced into the engine, and therefore, more fuel can be added to increase performance.

The performance of a supercharger depends directly on how fast it spins. To compress air, a supercharger must spin much faster than the crankshaft. To make this possible, the fan-like cast, or a different design compressor, inside the supercharger is connected to the pulley driven by the belt through a set of gears. The largest of them, known as a drive gear, is rested on the same shaft as the pulley, while the other one, called a driven impeller gear, is smaller in size and features the fan on the other side of its shaft. Due to the difference in diameter, one rotation of the drive gear causes several or more rotations of the driven gear and the compressor.

There are three main types of superchargers used in high-performance and race cars. They’re roots, twin-screw and centrifugal ones. The main difference between them is the way they force air into the combustion chamber. The first two utilize different types of meshing lobes, while the last one features an impeller. Roots units are the oldest type of superchargers, yet the least efficient one compared to twin-screw and centrifugal counterparts. The latter one is the most efficient and common type of superchargers found in today’s race vehicles. It is compact, lightweight, and can be mounted to the front of an engine instead of its top.