•  A wastegate valve, an exhaust-pressure control type valve with a simple structure, has been adopted.

•  When exhaust pressure is low, the wastegate valve is closed by spring resistance from the wastegate damper spring.

•  When exhaust pressure from the exhaust manifold exceeds the set value, the wastegate valve overcomes spring resistance of the wastegate damper. As a result, the exhaust pressure is released to the turbine wheel downstream and the air charging pressure is controlled.