Hello all,
I just got my 99 2.2 turbo project on the road last week and I'm having a little bit of a problem with my BOV. Its making a kind of fluttering sound when it blows off instead of the regular whoosh or whistle. I have a Greddy type S style BOV. I read in another forum on how to hook up the vacuum line and i checked that out and its hooked up correctly. Just wondering if anyone else has seen or heard of this before. Thanks for your time!
Sounds like it might be set too soft, try adjusting it more to the hard side. Don't get carried away though, you don't want back spin.
if its fluttering it's top hard, it needs to be softer
LE61T PTE6262 Powered 
Could be that it's a knockoff Greddy "style" BOV.
But yeah...loosen it up, then it should stop fluttering.
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450WHP Turbo Ecotec swap in the works...
I've got a Turbonetics Raptor and it does the same thing. I've tried every possible setting I could, I changed out the springs, made it all the way hard, all the way soft on both springs, same result, I thought it was normal. I actually like it, it has one big pulse and several small ones after that. Don't know if it's good or bad, but it's different.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
Do you get a "woo woo woo woo" like the 3 stooges? Lol...mine did the same thing but we never got time to adjust. I agree with Phil, though--if you're running very little boost and the BOV is set up to expect more pressure, you'll probably wanna make it a little softer and go from there.
Yep.
See mine flutters all the time (Tial 50mm BOV) but mine is designed to do it...
LE61T PTE6262 Powered
It'd be good.... if only you were turkey hunting LOL
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Light fluttering won't hurt anything. When the valve opens most of the air comes out and just a small amount surges the turbo. It's not nearly enough to cause it to fail.
Now if you're at full boost and you let off and the valve doesn't open at all, you'll hear what sounds almost like a loud whispering bark (best way to explain it), which will then die down to a flutter. That is when major surge is happening and left alone will make short work of the turbo.
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450WHP Turbo Ecotec swap in the works...
Sorry, I meant too hard. Glad someone caught it.
Well when i was working on my car on Friday, i went to loosen up the spring on the BOV and i found that the set screw was no longer there! I think that explains why I was only running 2 PSI of boost and why it was fluttering so bad. But from what Spilner521 said about the surging, i think i have that going on now, so I'm gonna loosen up the bolt that i used to set my spring tension and see what that does. But if you guys have any more insight on this, i would be great! Thanks for you time!!
If you're running less than 10 psi or so just loosen the spring as far as it will go. As long as there's a vacuum line hooked up to the nipple (which there is if the valve is opening when you let off the throttle) the boost pressure will push down on the valve as much as it is pushing up on the valve, which will even out and let the spring tension keep the valve closed. It's when you start getting into the higher boost pressures is when the pressure in the pipes will overpower the pressure in the vacuum line, and then you need to start tightening down the spring a little.
Or you could get a SSQV and you wouldn't need to worry about anything.
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450WHP Turbo Ecotec swap in the works...
make sure u hook up the vacuum line on the bov to the manifold it makes the bov respond much faster and more consistent
I also have a greddy type s and am having the same problem. I got it adjusted as soft as it can go. I have a vac line from the top nipple on the Bov going to the mani. The other is vented. Am i missing something?
2nd Place is the first loser
SSQ is supposed to flutter correct?...i have a knockoff HKS and it sounds awesome cause the flutter goes loud to quiet......all my friends are like pshhh and mynes like csh csh csh cshhhhhhh
you scratch my ride IMA EAT YO CHILDREN
16 Valves Of Power wrote:SSQ is supposed to flutter correct?...i have a knockoff HKS and it sounds awesome cause the flutter goes loud to quiet......all my friends are like pshhh and mynes like csh csh csh cshhhhhhh
Not really. You're hearing compressor surge. You'd rather hear the pshhh like your friends'. The real HKS SSQV will whistle at light load, and at heavy load will make a loud pshhh with a whistle.
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450WHP Turbo Ecotec swap in the works...
OK guys I need some help. I have a greddy type s, softened up all the way and I still have surge. I have the top nipple hooked up to the mani and the bottom is vented.
2nd Place is the first loser
Also, forgot to mention, it'll surge a little if you let off the gas very slowly while at part throttle. If you let off quickly and the throttle snaps closed it'll blow off at part throttle a little better. Any light surge you do hear won't harm your turbo.
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450WHP Turbo Ecotec swap in the works...
