Turbocharger: Description and Operation

The turbocharger is an exhaust driven device which compresses the air charge being delivered to the engine through the intake system. The turbocharger increases engine power on a demand basis. Exhaust gases flow through a turbine that is connected through a shaft to the impeller wheel. During normal operation, the turbine does not rotate fast enough to boost air pressure. As speed increases, the air is compressed allowing a denser mixture to enter the combustion chambers, in turn developing more engine power during the combustion process. Intake manifold pressure (boost pressure) is controlled by a wastegate valve which is used to bypass a portion of the exhaust gasses around the turbine wheel at a predetermined point in the cycle, limiting boost pressure.

Fig. 1 Exploded view of TCS control system:

Turbocharger system components are controlled by the TCS (turbocharger control system) control unit which is built into the I-TEC control unit, Fig. 1.