[Scottycs]

EDIT: appears vaccum line was pinched where I zip tied it.

I have searched and can not find a definite answer. Just installed the cp/bov and it was extremely quiet, but at high boost I would hear the "pshhhhht" sound. I also noticed when shifting, the jb4 boost on fuel would jump up for a fraction of a second.

Today I installed DCI, and I can hear what appears to be compressor surge every time I let off the throttle at low/mid boost. Under heavy boost I get the "pshhht." If I let off gas at high rpm the boost jumps, and sometimes there appears to be a slight delay before the blow off.

Anyone else experience this? Do I need to change the spring? Any advice.

Thanks!

[Scottycs]

anyone?

[jb's335]

I have experienced the same when I let off in the lower gears or shift without taking my foot completely off the gas. Sometimes spring/diaphram type blow off valves do not work perfectly, but it also could be something with the engine and its vacuum system. But yes I would suggest trying another spring, one that is matched with the 20 in/hg this car pulls at idle.

[gmdoctor]

I was running cobb stage 2+ with this and was perfect. I wouldnt change the spring.
are you looking for more noise?
that flutter you hear is a partial open condition on the valve and is normal at lower boost levels.