The Loudest Bypass Valve

[TrqMnstr]

http://youtube.com/watch?v=v59A1zdMv80
How the freak do you make this sound more audible??? I always her this in the BMI videos and to me personally there is nothing like it.

 

[Poodles]

also keep in mind that with a stock airbox you more than likely won't hear crap...

How loud a recirculated BOV is gonna be is directly effected by what intake you have on the car...

 

[Rennat]

I personally got sick of my stock BOV on my eclipse... With a metal intake you could hear the damn thing every shift, on and off boost it would make noise... and it was a little TINY bosch bov... only doin 14psi...

My friend has a greddy type s, hes had it forever... i personally think it sounds like crap.
And after watching that subaru video, im almost 99% positive hes surgeing... lol

I would vote for the HKS BOV, they just came out with a new one, and it looks better than the original.

 

[starscream5000]

The synapse BOV has a really weird vacuum routing setup on it. There are two vac. ports on the back and one on the side of it. The two in the back are tee'd together, with either the top or the bottom one being the primary vac port first, you'd have to consult the manual to be sure as I've forgotten which one it is. The one on the side is plumbed into the compressor housing on the turbo for cars that are running more than 7 psi per Synapse's instructions.

The BOV itself comes with a weld on stainless flange with an o-ring on it where it goes up into the BOV itself to seal, think Turbo XS style here. You can buy adaptor flanges (like I did) if you just want to switch out your old BOV with this one.

 

[Tire Shredder]

before just trying to get the "loudest" consider that for that sounds to be created, kinetic energy from the air bypassing must be converted to sound energy. It's not a direct relationship, but basically...the louder your blow off valve or bypass valve gets, the closer you get to having a straight pipe with now blow off valve at all (more sound = harder for it to escape). and the closer you get to compressor surge

to me, just strictly air movement sounds good.

may be time to reconsider your tastes.

 

[Datsrboi]

So no one likes tial?

 

[Dan_Gyoba]

I found that Subaru video enlightening too. I'm not sure, but I think I'm getting some of that surge sound now with my stock BOV and stock CT26. (Maybe the BOV isn't working so good?) I guess I should get my IC pipes and that HK$ SSQV on there as soon as I can...

 

[Mr. Y]

The synapse BOV has a really weird vacuum routing setup on it. There are two vac. ports on the back and one on the side of it. The two in the back are tee'd together, with either the top or the bottom one being the primary vac port first, you'd have to consult the manual to be sure as I've forgotten which one it is. The one on the side is plumbed into the compressor housing on the turbo for cars that are running more than 7 psi per Synapse's instructions.

The BOV itself comes with a weld on stainless flange with an o-ring on it where it goes up into the BOV itself to seal, think Turbo XS style here. You can buy adaptor flanges (like I did) if you just want to switch out your old BOV with this one.

I've watched videos and haven't understand: is it open at idle and low load? If it is then it needs to be routed back to pre-turbo intake... Or attached to small air filter (on MAP systems) so dust and dirt couldn't be sucked through BOV. Right?
If so, then what is outer diameter of discharge flange (what hose ID can be attached to route back to pre-turbo)?

BTW, how does it handle big turbos?

 

[starscream5000]

You can buy a MAF adaptor kit for it that will allow no air to suck into it when at idle and in vacuum, but I would go with the reroute option out of anything. You could put an air filter on it if you choose to vent, but here's why I've chosen the re-routing option:

The stock computer setup on the Supra will only work properly if vented pressure in the intercooler piping is re-routed back in to the intake pre-turbo, post-AFM due to the air that's being vented already being metered by the AFM itself and adequate fuel being injected into the motor to compensate for that air. Also, re-routing the bypassed air into the intake pre-turbo will also help keep the turbo spooled more to a small degree, giving you a slight edge over an identical setup that's being vented. That setup will have a little longer time building back up boost than a re-routed setup.

I'll have to measure the re-routing flange this weekend when I have some spare time.

I don't have a large turbo at the moment, so I can't comment on that, but it should be able to flow as much, if not a little more than an HKS SSQV as the discharge is larger and the inlet is too IIRC...

The Synapse Synchronic BOV is more like the HKS Racing Type II than the SSQV in the regards of flow capabilities, but superior IMO than the regular SSQV in the sense that it is quicker to react.

 

[Mr. Y]

starscream5000
I've just visited Synapse website and found out that recirc. fitting is 1.25"

 

[87witmoreboost]

Is the bosch 110 an absolute direct replacement or do hoses need to be moved/cut/enlarged? I understand it has a stronger diaphragm but does it work quicker than the OEM BPV? Sound different?

 

[giterboosted]

ok i have the newest ssqv and i just want to know, is this a good one, ive always heard good things, i dont care about sound, itd be nice to hear it but whatever if i dont, am i good to go for now basically is what im asking? or do you all think i should change?

 

[Dan_Gyoba]

That's the one that I have, and will be installing.

If you vent to atmosphere, expect to have some issues, unless you switch to a MAP based system. While you're still using the AFM, venting that air to atmosphere means a periodic boost leak, with the attendant issues that causes, including stumbling, and puffs of black smoke at shifts.

Fortunately you can get a recirculation fitting for the HKS SSQV (Which is what I'm doing.) There are 3 sizes available, from what I gather. 19mm, 1" and 29mm. The 1" seems to be the most commonly available size here, and is what I'll be getting, since it's also far and away the cheapest. The fitting basically allows you to attach a hose to the valve so that you can recirculate the vented air back to the intake, like the stocker. This means that you aren't losing that air, so your AFM still works like it should.

 

[starscream5000]

That's the one that I have, and will be installing.

If you vent to atmosphere, expect to have some issues, unless you switch to a MAP based system. While you're still using the AFM, venting that air to atmosphere means a periodic boost leak, with the attendant issues that causes, including stumbling, and puffs of black smoke at shifts.

That's the whole point of a bypass valve .

 

[Dan_Gyoba]

That's the whole point of a bypass valve .

I suppose that's true, however, it's NOT the point to lose metered air. This is why the factory valve recirculates the air back to the post-AFM intake.

My point was that venting to atmosphere isn't desirable while using the AFM, and the valve should be recirculated back to the intake. After all, if you read the rest of that sentence, who'd want to install something where the point is puffs of black smoke, and stumbling?

 

[starscream5000]

Ricers would .

 

[87mgte]

ok i have the newest ssqv and i just want to know, is this a good one, ive always heard good things, i dont care about sound, itd be nice to hear it but whatever if i dont, am i good to go for now basically is what im asking? or do you all think i should change?

I installed my ssqv with a hardpipe upgrade, and I'm venting to atmosphere at stock boost with no stumbling or any other noticeable problems at all.