HKS BOV Flutter/Surge

emiliorescigno

Supramania Contributor
Sep 17, 2006
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Woodbury, MN
So about two months ago, I got a new intercooler/hardpipe kit for my 7M, and included with it was an HKS-style flange as an alternative for the stock BPV port. I purchased and installed a GENUINE HKS SSQV, and this damn BOV keeps surging.

If I drive hard, surging isn't such a big deal, it blows off just fine at 7+ psi, followed by a *tiny* little flutter sound. But at low speeds and part throttle, the BOV simply doesn't open. Driving briskly, but only reaching 3-4 psi, the BOV does not vent at all, and there is only compressor surge.

I tried running the BOV off of several different vacuum sources, both on its own and T'd off of good sources. Since this BOV is the most recent version of the HKS, there is no adjustment screw, so I'm at a loss as to what to do.

Any other BOVs that will fit the same style flange, so I can replace this BOV with a different, more responsive one? Any ideas with how to get the current BOV working properly?

Thanks for the help!
 

JDMMA70

Active Member
Dec 4, 2006
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Houston
The newer hks ssqv isn't adjustable like the older hks ssq. I would almost say sell yours and buy a older ssq. But the only other bov I know that fits the hks flange is the synapse but I don't like them that much.
 

gennro

New Member
Mar 12, 2008
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Alamogordo, NM
I have a new style HKS and it works just fine. Mine is located about 6" from the throttle body and the vac source comes straight off the intake manifold. This is also running on a 62mm turbo.
 

emiliorescigno

Supramania Contributor
Sep 17, 2006
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Woodbury, MN
DSC00040.JPG
 

emiliorescigno

Supramania Contributor
Sep 17, 2006
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rtrdpenguin;1597406 said:
Mine flutters too, but I don't really care haha. Flutter shouldn't really hurt anything, as long as the air is escaping enough for the turbo not to surge... where are you pulling vacuum from to open the blow off valve?

I guess I wasn't totally clear on this, but this BOV is surging at lower boost, no question, air does not escape the BOV in the 1-5 psi range, roughly.
 

mkiiichip

New Member
Sep 10, 2007
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SSQV's are known to flutter at low boost.
BOV's dont surge, turbos do.
How do you know that nothing is being vented at low boost?
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
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Perkasie, PA
The SSQV's normally do this. I own 2. Both leak like a mother, im kind of pissed. I can't even perform a boost leak check because so much leaks out from both of them it won't pressurize the system at all. Called HKS and they basically accused me of having knockoffs and I might as well buy a new one as repair costs would be almost the price of another. I am NOT a happy camper with the HKS'
 

Kevin

7mgte -> 7mgte swap done.
Apr 20, 2009
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Windsor Ontario Canada
are you sure you have a good vaccuum source? because i had the same problem.. but then switched to a source right off the manifold and it vents with VERY LITTLE flutter at 0-2psi and no noticable flutter from 2-7psi
 

emiliorescigno

Supramania Contributor
Sep 17, 2006
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Woodbury, MN
Well, for a slight update, I think I've squared the problem. The vacuum input on the HKS BOV is TINY!

Any vacuum hose that I try to use without using a coupler of some sort is too large/loose for the BOV port, or too small to fit on a TB port, or requires an adapter from an IM port. I put some zip ties VERY tightly around the couplers and things are seeming a bit better. It's still surging at low boost (1-3 psi), but not nearly as bad as before. I am still thinking about switching back to my Saab BPV though, which never had any problems at all.
 

89supra7mgte

New Member
Sep 20, 2009
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colorado
I have the same setup but mine is a knock off for now, works great. I noticed alot of surging/flutter sounds with it vented to atmosphere, re routed it to the accordion and all is well. Make sure you have it on the vac port on tb iirc you do not want ported vac. also if you are running stock afm i read on here its not the greatest for you turbo by venting to atmo. also have the stalling everynow and then from releasing metered air.
 
I use a 3mm silicone vacuum line on mine and it fits nice and tightly. I put a zip tie on there but I've run it without one temporarily on the track and it never came off or anything, so 3mm seems to be the right size :)

edit: no surge either, just flutter. and that's only when i barely hit boost, like less than 2 psi.
 

mk3tattoos

New Member
Apr 12, 2008
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Bremerton, Wa
you can always go with a synapse syncronic BOV, the use the hks flange and work great with no leaking at all. if you need install tips just ask me and i can help.
 

emiliorescigno

Supramania Contributor
Sep 17, 2006
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Woodbury, MN
redmaro;1599651 said:
Is the BOV you purchased new or used?

Used, unfortunately.

mk3tattoos;1599655 said:
you can always go with a synapse syncronic BOV, the use the hks flange and work great with no leaking at all. if you need install tips just ask me and i can help.

I've been considering it, but I've also been thinking about switching back to the stock BOV port and using my Saab BPV again. That never had any problems at all. How much are syncronics usually?
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
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Perkasie, PA
^wish they made adapters for those of us stuck with the HKS flange style so we could switch to tial or greddy, preferably tial.