What is the difference between an internal wastegate and an external wastegate?
An internal wastegate is an integral part of the turbo. On the t25’s and t28’s, the internal wastegate is the solenoid with a rod sticking out of it that sits on the side of the turbo. An external wastegate resides on the turbo (exhaust) manifold and reduces the amount of exhaust gas entering the turbo to decrease boost pressure.
