Description And Operation: Description: Turbocharger

The turbocharger is attached to the cylinder head with four studs and nuts and a multi layer steel gasket.

The turbocharger utilizes a twin scroll turbocharger. This has two turbine inlets, and separates the exhaust flow into pairs of cylinders. The upper turbine inlet is connected to the first and the fourth cylinder. The lower turbine inlet is connected to the second and third cylinder. The purpose of this is to reduce the effect of exhaust events between cylinders. When the exhaust valves first open a pressure pulse is released into the exhaust called the 'blowdown' pulse.

On a four cylinder engine, the 'blowdown' pulse occurs at a time when the previous cylinder in the engine cycle is still exhausting gas. The 'blowdown' pulse can therefore inhibit the exhaust process from the previous cylinder, increasing the amount of residual gas, increasing the tendency to knock.

There is a turbine bypass actuator fitted on the top of the compressor housing by three bolts. The turbine bypass actuator opens and closes the turbine bypass valve and allows the exhaust gas to bypass the turbine. The turbine bypass actuator contains a position sensor. The position sensor and the actuator motor are connected to the Powertrain Control Module (PCM). The actuator is controlled by Pulse Width Modulation (PWM) signal from the PCM.