I am running a 8.4psi spring in my truck and it will only make 6psi running off the wastegate. It was making 6.5-7psi until I fixed a boost leak now it is down to 6psi. This thing has always ran about 1.5psi lower than the wastegate spring pressure but I don't understand why it got lower when I fixed the boost leak. Is this due to backpressure or what?

 

This is the pressure drop across the intercooler and piping if your wastegate is referenced at the turbo outlet instead of the intake manifold.

 

The wastegate is referenced from the intake. I'm not going to make it that easy. LOL

 

Do you have a controller?

 

Yeah, I have the STS 0-15 electronic controller.

 

how big is the wastegate??

 

I believe it is a 46mm. It's a knock off that I got from Kyle a long time ago and it looks like the Tial 46mm. I measured the opening in the wastegate and it is right around 46mm.

 

step up the controller..
i just installed mine today...running a 10# spring and have like 7.5# of boost in this heat...hooked up the manual turbosmart in cabin controller and turned it about 3/4 turn and i got my 10-10.5# of boost back....

 

I have high boost set on 13.5psi right now. I'm wanting to run 7-8 on low boost but I don't want to buy another wastegate spring. I already have a 5.5, 7.2 and 8.4psi springs and I don't feel like spending another $35 to get a 10psi just to run 7.5psi off of the wastegate.

 

maybe its just bleeding off alot of exhaust being that the gates huge. i have a 7psi spring in a 36mm gate and run 10psi.