WASTEGATE & BACK PRESSURE

The wastegate controls boost pressure and releases it when it isn’t required. A standard wastegate releases boost pressure into the exhaust system. This contributes towards unwanted back pressure. The easiest solution to this problem is to release the unwanted boost pressure into the atmosphere. This can be achieved via an external wastegate. Unlike an integrated wastegate, which is part of the turbo, an external wastegate is separate to the turbo and mounted onto the exhaust manifold. According to turbobygarrett.com, the angle of the external wastegate when mounted to the exhaust manifold is important. The website recommends a 45° angle to the manifold – any greater and airflow can be greatly reduced, resulting in less control over boost pressure.