Turbocharger — General Description (Audi A4 B6)

The main purpose of supercharging is to improve the filling of the cylinders with fresh air, which is necessary for the combustion of fuel, i.e. to increase the engine power. A means of achieving this goal can be a compressor with a mechanical drive, but such a compressor consumes some of the power. For this reason, a more popular solution is a turbocharger, this supercharger uses the exhaust gases as energy for the drive, which pass through the exhaust manifold at supersonic speed.

Basically, a turbocharger consists of two impellers that are located on a common shaft.

The gases pass through the turbocharger housing, where they spin the rotor (first wheel) up to 100,000 rpm. The rotor drives the second blade wheel via the shaft (impeller). The impeller draws fresh air into the turbocharger housing and forces it into the combustion chambers.

In positive-ignition engines, when turbocharging is used, due to the large amount of air supplied to the combustion chambers, the compression must be reduced compared to a naturally aspirated engine so that the engine does not exhibit a tendency to detonation combustion at full speed. As a result, the efficiency is reduced.