ok i got a wastegate with the kit i got on ebay, and im not sure what size it is I forget what it said. I also want to change the spring for a different psi. How do I measure what size it is? Is it the complete spring diameter or just the diameter of the inside of the spring for when it fits on the bump/vent in the wastegate? I measured both and the diameter is 47mm and the inside is about 39 mm it looks like. thanks

 

wastegates are sized by the size of the piston that actually does the dumping.

measure the hole on the side that bolts to the manifold.. you'll see the piston chillin there shut