What is the purpose of a wastegate?
On the exhaust side, a Wastegate provides us a means to control the boost pressure of the engine. The vast majority of gasoline performance applications require a wastegate. There are two configurations of wastegates, internal or external. Both internal and external wastegates provide a means to bypass exhaust flow from the turbine wheel. Bypassing this energy (e.g. exhaust flow) reduces the power driving the turbine wheel to match the power required for a given boost level (speeds up or slows down the turbo). Similar to the BOV, the wastegate uses boost pressure and spring force to regulate the flow bypassing the turbine. Internal Wastegates are built into the turbine housing and consist of a flapper valve, crank arm, rod end, and pneumatic actuator. It is important to connect this actuator only to boost pressure; i.e. it is not designed to handle vacuum and as such should not be referenced to an intake manifold. External Wastegates are added to the exhaust plumbing on the exhaust man
