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System overview

System overview


Brief description

Unlike a conventional aspirating engine, a supercharged engine is provided with an increased mass of air during the intake stroke, which provided improved combustion, increased power and higher torque. The engine performance is therefore comparable to that of a larger engine but it retains the advantages of a small engine such as space, weight, etc.

Supercharging

Supercharging is done with a turbocharger. The turbocharger is driven by some of the engine exhaust gas. The exhaust gas is passed through an exhaust turbine that rotates the turbine impeller. The turbine impeller is mounted on the same shaft as the compressor impeller and rotates at the same speed. The compressor impeller is located in the induction system and accomplishes an increase in pressure there that gives rise to a greater volumetric efficiency in the combustion chamber. In order to be able to govern the additional air mass from the turbocharger, exhaust gas is led past the turbine section of the wastegate when the engine produces more exhaust gas than is required to drive the turbocharger. The wastegate position is controlled by Trionic.

The turbocharger is designed to start working at relatively low engine speeds and therefore delivers a high torque in engine speed ranges that are common in normal driving conditions. The turbocharger on the B235R and B205R is a Mitsubishi TD 04 and on the B205L and B205E it is a Garrett GT 17.