GM MAS and BOV after whistle

[DSMcamaro]

So all my mods are in my profile, but I think the main thing here is that my BOV is vented properly with the MAFT. Anyways, if im driving and build boost and let off the gas the bov does its normal woosh and then after about 1 or 2 seconds its does this whistle type of sound happens. and its kind of drawn out. this is at about 15-10lbs of vacuum... and if i hit the gas a little it goes away. Now, im thinking the BOV might always have done this but I just wouldnt here it when its recirculated. It started doing this a while back when I had my dodge mod 1G BOV on and I figured the sound was just because of the dod mod. So I put my crushed 1G bov on and it went away for a while. Now about a month ago it started coming back but it wasnt as long or as loud as it was initally with the dodge mod bov. Today I re-routed my MBC line so it wasnt T-ed off the BOV line anymore and it seems a little louder now too. Sorry for the long rant but just thought i'd tell about everything that I thought could possibly cause this.

edit: just thought of something. I modified my J-pipe when i built my intercooler piping and cut the nipple off, but when I had my dodge mod bov hooked up, i put a differnt nipple in the piping about 7 inches away from the throttle body after the bov. I'm using this line for my MBC, maybe this could have something to do with it. Also, its this a bad place to have my MBC line taped..... should it be before the BOV and before the intercooler like it would be off the j-pipe?

 

[tstkl]

if its a 1g bov, quit trippin, all ours do that too.

I can make mine last for almost a minute too, you just gotta control the gas perfectly

 

[DSMcamaro]

Im not too worried, i've delt with it for a while but finally got around to posting about it. thanks for the info, I was hoping it wasnt just a freak thing with my car.

I can make mine last for almost a minute too, you just gotta control the gas perfectly

sounds like you got some skills

 

[TimG]

Mine does it also. Sorta sounds like squeeking brakes under the right conditions. It's just a whistle.

 

[DSMcamaro]

Update. So after hooking up a differnt boost controller and tapping off the intercooler piping for a pressure source, I found my BOV was opening prematurely so I hooked it back up being T-d off the BOV line. And guess what, that after whistle is basically gone again. How do the rest of you have your MBC hooked up?

 

[tstkl]

mine still did it with no mbc at all, and when I did have an mbc taped off the bov line. Its the small pressure difference created by a closed throttle plate on a faster spooling turbo. Thats why i can do it for so long, you close the throttle plate most of the way, and slowly close it, at just the right rate, and the exhaust gases are still enough to create a little bit of boost over what is being seen in the intake manifold because the throttle plate is blocking most of the pressure.