Turbocharger: Description and Operation

NOTE: For diagnosis of Turbocharger control system and electrical inputs, please refer to Computerized Engine Controls.

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