Did a little searching.. couldn't find anyone talking about the same issue unless I wasn't searching for the right words. I'm wondering if anyone may have a recommendation for this:
Installed a grimmspeed ebcs and had a custom stage 2 tune about a year ago. During the tune as boost levels increased slightly, (what sounded like) my turbosmart dual port bpv started sputtering or fluttering at full throttle in 3rd-5th gear especially, while seemingly maintaining a solid boost level on the boost gauge. I continually tried adjusting the valve until it was as hard as it could go, still happening. Tried a stiffer spring thinking I was out of the spring's range, and tried replacing the stock bpv, both with same symptom.
Could this just be a simple seal issue on the valve that I just haven't nailed down? Seems funny that both the cardboard gasket used for the turbosmart valve and the rubber stock valve gasket could have the same issue.. I also never had the issue before the ebcs running about 20 psi, and now at 22 psi. Maybe the ~2 psi could've pushed the seal over the edge..?
I was also thinking it could just be the nature of how the ebcs is plumbed.. so it's just making the sputtering sound at high boost.
The car's running great and it's just annoying, so figured I'd see what anyone thinks. Thanks