Will turbine pressure increase or decrease compared to compressor pressure when the wastegate is opened?
Turbocharger waste gates are one of the most essential, yet misunderstood, aspects of turbocharger performance. Too often, enthusiasts make adjustments to the waste gate without really knowing why they’re doing it, or what effect it will have on the engine’s power production. In simple terms, a wastegated turbine housing is designed to yield faster low end response and stabilize boost pressure when the gate is opened.
To understand wastegating, we must remember that a turbocharger is an exhaust-driven centrifugal supercharger, which means that the turbine must develop sufficient power from the exhaust to drive the compressor wheel as pressures and flow increase.