We get a lot of calls from customers about wastegate actuators, how they work, and asking how to adjust them for different boost levels.
This post will be a explanation of how a wastegate actuator works, and then we will discuss how to adjust the wastegate actuator to your desired boost level.
First off, for those of you who may not be familiar with the inner workings of a turbo, a wastegate can be designed two ways. Most commonly found on factory turbos is the internal wastegate (what we will be discussing here) and the external wastegate. The internal wastegate is a bypass that allows exhaust gases to be routed past the turbo. The sole purpose of the wastegate is to regulate the amount of exhaust flowing through the turbo, therefore controlling the boost pressure the turbo is putting out.
In this photo, youll see the wastegate flap on the left, and the fins on the exhaust side of the turbo. Normally the wastegate flap will be closed, therefore pushing the exhaust gases out through the exhaust side of the turbo, therefore building up boost.
The wastegate actuator, is a pressure device, that once it reaches a certain pressure (8, 10, 15 psi) will activate, and open the wastegate flap. When the wastegate flap opens, exhaust is routed around the turbo, therefore creating a consistent boost pressure output from the turbo.
So, now that we’ve explained all of that, lets get into more details of the wastegate actuator. Since the wastegate actuator controls the boost level, making adjustments to the wastegate will directly change the level of boost! If you want MORE boost pressure, then youll need to make it so that the wastegate actuator opens up later than normal, or shortening the wastegate rod so that it pulls on the wastegate flap harder.
If you want less boost, lengthen the rod so that it will open the wastegate sooner.
Heres a photo of a AGP Wastegate actuator for the 03-05 SRT-4. In this photo you can see that the end of the wastegate is adjustable, and you can make it longer or shorter to adjust the boost levels.