i have the stock TMIC setup still with stage 2 hybrid and a SSQV and put together a friends Greddy FMIC, BNR stage 4. we both have the flutter and i have tried several vacuum sources. i just don't think the SSQV likes rotaries much.

 

That's exactly what I said.

So what's the adjusting bolt and locknut on the end for?

http://www.overboost.com/picture.asp...i=DSC07144.JPG

 

that is for the secondary plate opening, it doesn't adjust the valve opening timing at all. basically it is to change the 'sound' of the BOV when it opens.

the internal diaphragm is what sets the vacuum threshold to open the valve, it can't be changed to time it differently that i know of.

i even chopped the spring down to try and cure it, it did absolutely nothing even with the spring having near 0 pressure on the plate.

i learned to just live with it, or i may possibly use a different BOV when i finally do convert to a FMIC.

 

I have a S5 hybrid, FMIC, and a Blitz BOV and i too have the same problem. I kind of dont like the fluttering sound it makes. I loosened the adjust screw a bit on the BOV and it now make a longer psssssshhhh sound. SOmetimes i just let it boost to almost 5 psi then shift to hear a complete more pssssssssh sound of the BOV.

 

That's what I described above. Well I'm glad I'm not the only one with these issues but kinda sad that nobody has figured it out yet. Maybe I'll try a different BOV. TiAL sounds yummy.

 

im gonna keep adjusting the BOV and try to look for the sweet spot if there is any.

 

So, seems like the moral of the thread is...

Deal with it?

I don't like that to much but...I guess that is what we will have to do.

Although, it would be intressting to see somebody with a SSBOV on the TB side of the intake system. See if that happens to them.

Seems like you need to login for that picture....
Host it over here?

 

That's wierd, if you click that link from within the article you don't need to log in.

http://www.overboost.com/story.asp?id=1067

It sounds to me like this BOV is just an over-designed POS. Not being able to adjust it to open at a particular vac level like every other BOV out there seems crazy. Instead you get 2-stage noise. Great...

 

what damages does compressor surge do to the turbo?

 

I am guessing if it is bad enough it is going to beat the hell out of your compressor.

Yeah, this is really annoying. I have yet to boost past 1psi. However, when the BOV does work since I am still boosting to the 0 Psi point....it is almost this .... stupind squeaking noise.

I do not know WTF is going on with this BOV. I am going to have to work with it or figure it out. Since I am rather commited to it. Seeing how it's flange is welded into my Greddy FMIC kits piping. Yey.

James

 

moving it to the throttle body side wouldn't affect it unless it was a push type of BOV, the SSQV would act the same no matter where in the intercooler piping you put it however the sound might change some.

too bad i told smogsux that i would sell him my type S BOV because i would otherwise try that setup rather than live with the compressor surge or i may just dig a little deeper and try to find a better vacuum source but i don't see how that is possible since the stock location runs right into the intake runners.

 

Short of installing an electric vacuum pump...I don't see how you could find a better source under the hood

James

 

I know the exact sound you are talking about. It's either that annoying sqeak from the bov opening for normal driving or surge. I think I may switch to a larger bov like Tial.

Does anybody agree with me that it's the increase volume of air in the pipes that make it difficult for the bov to vent all of it quickly enough without the valve sticking open for a longer period of time and even under boost to vent all of it without surging?

 

i used to think that the hks didnt move enough air... i pulled the whistle out. itsd dead silent.. you can just barely hear it.. doesnt sound restricted to me anymore. i hear a fluttering sound with my bnr stage 3 too but its just my wastegate...

 

Mess with the adjust screw on the BOV. I run the SSQV with the stock top mount all day long and don't have any problems with it.

I have seen it get a little weird on some higher HP cars but the screw usually fixes it. Remember, loosen the screw and the valve is easier to open.

 

I really think this is an issue due to the large fmic.

I am gonna pull that insert...this noise is BS.

Anyways...you just undo all those allen headscrews to pull the insert?

James

 

Sorry to bump this but I'm just wondering out of all the people with the greddy fmic kit who get the flutter sound:

Where is your bov located? Hot pipe? Cold pipe? Do the people with on the TB side get the flutter.

I have mine about 1 feet after 90* bend on the outlet on the hotside. Some people say that mounting it closer to the TB makes it more effective so I'm wondering if relocating the TB to the cold pipe would solve the problem. I've seen pictures of setups with the bov on either side ranging from high hp setups to mildly modded but this is the first thread I've read about it. Just want some confirmation befor I cut another hole into another pipe and have a flange welded and threaded.

What's the argument for having it closer to the TB? So the bov will open sooner and vent more or the boost faster before reaching the turbo?

 

I have my SSBOV in the same spot you do....except mine is under the pipe against the wheel well.

Best reason I heard to put the bov on the hot side was....when it blows off...you are blowing off hot air. But if you put it on the cold side you are blowing off cold air....so all the work the fmic did to cool it was just wasted. So, you just blew off the cool air and the heat from that air is still in the intercooler....waste.

James

 

your bov will still whistle below 0 lbs of boost.... i dont know if i alreayd mentioned that....

 

i have the flutter and my bov is on the cold side, but i found an intercooler leak. maybe that'll fix my problelm

 

Damn, my BOV is on the cold side, and it does the same fluttering sound, i can even hear the turbo surge, its very annoying. I'm thinking that the vaccume source is our problem, not BOV location, IMO. I have to change all my vaccume lines anyways, i'm gonna try them all and see whats up.

 

All you have to do is soften the spring in the BOV. Im not sure about the hks unit but on my greddy type s you can adjust the spring tension. Give HKS a call and they should be able to help you out.

 

^^^ Meh, there is no adjustment for that.

I did remove the insert with the fins on it. However, it still makes the flutter noise. But it is less squeaky. All in all I heavly regret buying this model.

James

 

Well I have a BLitz Dual Drive BOV and get comp surge on my T04. It's all about BOV adjustment, if I had an alternator I'd be able to adjust it and get rid of it...

*sigh*

 

Are you guys running dedicated vacuum hose sources for the BOV's???
Try not to split vacuum hoses to add the BOV!


-Ted