What is a wastegate Internal or external, a wastegate is a boost-controlling device that operates by limiting exhaust gases going through the turbocharger, controlling the maximum boost pressure produced by the turbocharger itself. A wastegate consists of an inlet and outlet port, a valve and a pressure actuator.
How a wastegate works A pressure actuator, controlled by boost pressure determines whether the wastegate is open or shut. In its resting position, a wastegate is shut, and as the boost pressure builds, force is applied to the actuator. When the boost pressure exceeds the spring value, the actuator will progressively open the wastegate, bypassing some of the exhaust gases therefore maintaining the boost pressure at the set level. To put it simply – a wastegate prevents the boost pressure from climbing indefinitely and consequently blowing the engine.
When is an external wastegate needed Most of the factory turbo systems feature an internal wastegate made to handle stock boost levels. The most common reason for investing in an external wastegate is fitting an after-market turbo or better control of the boost and consequently the power output of your engine. Additionally, most large frame turbochargers are not equipped with internal wastegate systems. Most tuners will recommend an external wastegate for any engine producing 400hp or more, as running high boost through a factory internal wastegate can overpower the actuator spring, limiting maximum boost level. Aftermarket external wastegates feature bigger inlet and outlet ports, higher pressure springs and bigger actuator diaphragms to effectively control high boost pressure.
What’s so special about Turbosmart Wastegates Turbosmart wastegates offer superior flow path and high temperature resistance. They market leaders in their sectors, outperforming and outlasting the competition. Used on thousands of race cars, boats and plane around the world, they are used and recommended by a number of World Champions.