wentbig

I have searched and read this forum up and down for how to quite the bypass air vented.

Recirculate, Air too hot and not much reduction in noise.
Filter on valve, Has little or no reduction in noise.

I am using the little 1.5" vac controlled valve ProCharger sells.
Yes they leak, Yes it is too small for the amount of air we are moving.
The hiss is caused by the valve it amplifies the noise because of its poor flow.
Remove the valve and almost all hiss goes away. I understand we need the valve so this is the $10.00 fix.
Remove the Micky Mouse filter from the bypass valve and clamp a 1.5" hose in its place. Run 36"-48" of hose and tie it behind your bumper or any handy spot.
The bypass valve hiss is silenced by the rubber hose. I put the filter at the end of the 36" hose just to keep critters out. Take you razor knife and slice the outside screen and paper 6 or more spots, the filter will look closed but be able to dump big air if needed.
Some of you say the hose pulls vacuum sometime, NOT. Anytime the engine is running air rushes out not in. At boost air rushes out, remember they leak at the valve.
Hope this helps, its sooo simple I can't believe you gear heads did not post it.

Exidous

iTrader: (11)

I think the biggest reason is most don't care about the bypassed air as long as "it go fast".

I run a turbo bov with a 1lb spring that feeds back into the charger intake. The line is about 2ft long. Works well.