I performed that test already. Ran it atmospherically and by the time I got back from around the block I put it back...It did get a little more pronounced (worse).

Could it have anything to do with the fact that it recircs to one of the two intakes only?

What I dont get is why you guys think its the BPV when it makes the noise under throttle and the BPV should be closed at that point..

It makes the noise when you let off the throttle.

That's weird, this bypass valve shouldn't make any noise at all.

During idling the bypass valve should be slightly open, throttle should be closed, in between shifts open.

It could be an issue with trying to control that part throttle boost; if the system is trying to regulate part throttle boost by rapidly opening and closing the BPV rather than holding the diaphram partially open could be an issue with how the vacuum from the intake manifold pressure drops to a vacuum and thereby operating the BPV or in unequal pressure between the intake manifold and the intake plumbing.

Somebody is pretty smart and on the right track.

in for dyno numbers

Control boost? this is a BPV, not a wastegate. Completely different functions and mechanisms that operate with the opposite pressure. Wastegates open when a certain positive pressure is reached and bpv's open with vacuum. BPV's dont regulate anything, they just vent. Wastegates also vent, but they are bleeding air to regulate how much boost is made.

What you are talking about is wastegate flutter with an old/slow boost controller.

I didn't word my post well, I was thinking more about the fact that at part throttle in the mid rpm range, the VVEL is controlling throttle more than the throttle plates. Since a BPV releases pressure after the throttle plate has been closed on a normal FI car as opposed to the throttle body being open and VVEL controlling throttle, could this possibly cause an issue?

It is just an idea, I could just be babbling but this seemed plausible since it happens around 2-3k rpm just where VVEL is working its magic.

The GTM S/C kit for the VQ35HR engine has the flutter problem too.

Ah, that's a different matter then. Disregard my posts, sorry for my ramblings!

AK,
Hi. I know you posted in other threads requesting people to refrain from personal attacks. Someone tagged this thread with "RCZ fail". Can you help us here to stop the continued personal attacks?

Thanks,

-Phim

I think this as mine does not make in under load. Not saying others don't but mine does not make in under load.

^However, CGMobile says it's happening with the VQ35HR kit too which only has a single intake I believe.

Are most of you with the SC running HFCs or LTHs? Pardon my ignorance but I would like to know if the LTHs make a huge difference once you go FI.