[Shane@DBPerformance]

What spring is in your wastegate? If it's anywhere near 1bar, then your duty cycle is probably set way too high.

You might also want to hook it up the proper way for an external, using both ports on the wastegate. You can use it just like an actuator or manual boost controller setup, but it won't be able to handle as high of boost. By hooking up to the top port, it makes the wastegate act like it has a stronger spring in it by using boost to hold it shut. A weak spring can be pushed open by the exhaust backpressure, which often limits the amount of boost you can run to around twice the rating of the spring. So, using the top port pushes boost to the top side of the diaphragm and lets you run much higher boost with a weak spring.

Maybe draw a pic of what you have going on, if it isn't just too high of a duty cycle to begin with.