Bypass/Blowoff valve thoughts

[BrianFiebig]

I have a question or few about the whole BPV/BOV thing.
Seems to me that Mazda designed the car specifically for a Bypass, even if the actual unit seems to be considered to be a hunk of night soil. The rage seems to be to convert to a Blowoff, usually the HKS Super Sequential that every online shop seems to have.
Are there any documented (and I will want proof, as much as I trust butt-dynos...) advantages performance and fuel economy wise to going either way (or hybrid). My Speed is my daily driver, but I come from a LONG line of lead foots (I have boot-leggers in my family tree, and a 80 year old grandmother who refuses to use cruise control because its less fun). All this being said, I would like to know what route is better for a occaissionally hard driven car (I have a thing for ricers, I call my commute, especially on friday and saturday nights, Hunting Time). I wouldnt say no to a LITTLE whistle, but I am of the mind that compressor stall and the resultant way too fat condition to be a Bad Thing. Ideas? I know there are a few hybrids out there, but how many people have them and are satisfied, any performance/economy gains VS stock, Aftermarket Bypass, and aftermarket Blowoff.

Sorry this is a convoluted post.

[Rotus8]

I am not sure where you get "The rage seems to be to convert to a Blowoff". Lots of people have tried it and it doesn't work well without a tuning solution added as well. There are a number of choices for improved bypass valves, and if you are into funny noises, a SRI or CAI enhances the auditory experience, as well as adding significant performance.

[ZyrehT]

BOV/BPV will not change hp or fuel economy. Unless you start upping boost/power and worry about it leaking there really isn't any reason to change except for sound.

[AAMguy]

http://www.mazdas247.com/forum/showthread.php?t=123724091

[CWPspeed3]

http://www.mazdas247.com/forum/showthread.php?t=123724091

Your too nice, he didnt even have to do a search

[Gmac03]

Change it if you want, but do stick with a BPV. The car isn't designed for a BOV. Period.

The stock plastic bosche piece has historyically leaked on all of my SR20DET engines. I have always upgraded that piece due to it having issues holding boost over 12psi. Not sure if it is simply the design or the fact that it's plastic. But if it's not metal then i'm not very fond of it.

I haven't tested the the stock piece, but plan on it.

But do stick with the BPV.

Gmac

[okpanic]

I had a bov installed on my old sti for about a month. If anything it hurts your fuel mileage simply because you will use the throttle more to avoid the annoying backfire that happens with all bov's. I have never been happy with the stock bpv on my old suby or on my new ms3. They both seem to have a tendency to leak in the higher boost ranges. on my suby I found a much better aftermarket bpv that would hold solid up to 30 psi. I haven't found the same quality bpv for the ms3.

[Gmac03]

You could be the first to run a blow-thru setup. Then have at it with the BOV.

Gmac

[ZyrehT]

I haven't found the same quality bpv for the ms3.

Then you haven't looked at the Forge.

[DaleNixon]

Get a Forge BPV and be done with it.

[AutoEuphoria]

It's less BPV and BOV...I think those are basically two terms for the same thing. It's recirculated or vented to air that really matters. You can run a BPV vented to air and it will run like crap...or you can run a BOV recirculated and have it run fine (as long as you get it dialed in right).

I recommend the Forge unit. I have it, and it hasn't given me an issue yet.

[714ms3]

It's less BPV and BOV...I think those are basically two terms for the same thing. It's recirculated or vented to air that really matters. You can run a BPV vented to air and it will run like crap...or you can run a BOV recirculated and have it run fine (as long as you get it dialed in right).

I recommend the Forge unit. I have it, and it hasn't given me an issue yet.

They are not 2 terms for the same thing. Bypass = air is diverted/passed back into intake system. Blow off = air is blown off into the atmosphere. The only time you can run a BPV on vent to atmosphere is on the hybrid systems (they do a little of both, and can be adjusted).
But I totally agree on getting the Forge unit.

[AutoEuphoria]

Well, what I mean is that you can buy an HKS SSQ BOV and run it recirculated...and it would more than likely work better than a Forge BPV vented to atmosphere.

[mazdaspeedster3]

A BOV with a recirc adaptor. A BOV is not designed initially to Bypass hence the recirc valve, additional part to purchase when for $145 a Forge will do the same thing, look more stock, not rub on your hood and ultimately break. The only other I would recomend is the turbo full BPV, a little more $$ than the forge but has a stock sound.

[djza2u1]

Don’t go with a straight BOV, either go hybrid or BPV. Jan's Modified Mag has an article about this dilemma and they have a couple of graphs that show a car made for a BPV will loose top end boost if converted to VTA. If you want more proof I will scan the article when I get a chance.

Side note: Aftermarket BPV sounds like a super Mario game. I purchased the forge BPV, and now I have the turbo smart hybrid Duel BPV/BOV. I have not put the forge BPV for sale yet, but i can if anyone here is interested. (black finish)

[mdavis]

Side note: Aftermarket BPV sounds like a super Mario game. I purchased the forge BPV, and now I have the turbo smart hybrid Duel BPV/BOV. I have not put the forge BPV for sale yet, but i can if anyone here is interested. (black finish)

Interested PM me!

[john blutarski]

Get a Forge BPV and be done with it.

nuff said...

although I sold mine and bought a Turbosmart

[DaleNixon]

Why John?

[Abilor]

Why John?

Yeah, why? I have my finger on the trigger for a forge right now...

[DaleNixon]

Dude go for the turbosmart! We can compare valves!

[djza2u1]

Just spend the money for the turbosmart and you wont regret it.

[Abilor]

Are you talking to me? But I want to grab coins! I will investigate this turbosmart of which you speak...


Dude go for the turbosmart! We can compare valves!

[Abilor]

Dude, thing is pricy. I dunno. No backfire? For real? Would I want to run this in hybrid mode? I was thinking of getting a hybrid BPV/BOV back in November, and everyone here said I was nuts, go forge. Why the change of heart? What's so keen about the turbosmart?

Convince me to spend...

[djza2u1]

First of all you get what you pay for. The BOV/BPV set up that i run has not problems, and i have constantly checked the vacuum/boost with my dashhawk. In fact i hold my peak boost 360rmp longer with the forge and turbosmart, but with the turbosmart i peak 130 rmp earlier.
And it is from Australia, I've never hear or anything bad come out of that country. Except Crocodile Dondee 3

[john blutarski]

Gentlemen... I love the Forge for performance and price but I got tired of the sound and I think the TS sounds the best. That's right, I switched it out just because I think it sounds better. As for holding boost, they both performed similar for me.

[Abilor]

At the Store of the Blasphemer, Woe Art Thou of Whom We Do Not Speak (SOTBWATOWWDNS), are they basically just painting turbosmarts with their own custom color scheme? Are the seven different versions all turbosmarts? And are they reliable to buy from?

[DaleNixon]

Yes they are reliable man.

I'm pretty thrilled with the Forge, I'm just being selfish and wanting to hear a different BPV. You'd definitely want to run it at least hybrid but most likely recirc.

[patty AT forge]

People use the two terms interchangeably but they aren't the same. Blow off valve = atmo. Bypass valve = recirc. We make both. You absolutely cannot run a single piston (or diaphragm) bypass valve on a MAF car, there will be a massive vacuum leak at idle and whenever the valve vents.

And for those wanting our valve without the sound... just wait.

[Rotus8]

People use the two terms interchangeably but they aren't the same. Blow off valve = atmo. Bypass valve = recirc. We make both. You absolutely cannot run a single piston (or diaphragm) bypass valve on a MAF car, there will be a massive vacuum leak at idle and whenever the valve vents.

And for those wanting our valve without the sound... just wait.
I'ts hard to wait, now you have given a hint. Any more info? I like the performace of the Forge, but the tink sound is a bit weird...

[funksilver07]

My Forge BPV performs flawlessly, I have zero issues with the sound. This piece installs in 15 minutes and holds boost. Personally, I don't see the point in spending almost twice the $$$ on other units (as good as they may be) and then run in recirc. mode, whats' the point? You've spent all that extra money to not use the VTA. (shrug) If your tuned for it fine but if not run a Forge, it's a great part.

[DaleNixon]

NOOOO!!! Don't take away the mario coin!

[SpooledupRacing]

ok.. I id not read it all but here is the difference..

BPV's will push the air back into the compressor keeping the turbo spooled during shifts..

no u wont have full psi between shifts.. but with a bov your compressor will drop normally to 2psi or less (most the time back to hg) and u will have to spool from a stop again..

with a BOV the air pushed back into the compressor will keep the turbine spooled at 4-5 psi during a shift so u dont loose all boost.

I still say bov and get all of the air out of the system so u dont have any back surge on the compressor..

[john blutarski]

ok.. I id not read it all but here is the difference..

BPV's will push the air back into the compressor keeping the turbo spooled during shifts..

no u wont have full psi between shifts.. but with a bov your compressor will drop normally to 2psi or less (most the time back to hg) and u will have to spool from a stop again..

with a BOV the air pushed back into the compressor will keep the turbine spooled at 4-5 psi during a shift so u dont loose all boost.

I still say bov and get all of the air out of the system so u dont have any back surge on the compressor..

Dave,

I think you're misunderstanding it a bit. Any air that would help spool up the turbo quicker would need to be routed back to the intake tract pre turbo. This can only be accomplished with a recirculating valve (BPV or hybrid). A BOV blows all that air to atmosphere and has no way of recirculating it. In regard to compressor surge, we're talking about post turbo air backing up against the compressor wheel. This can happen with either a BPV or BOV and is fixed by simply adjusting the spring tension of the BPV/BOV.

[Abilor]

I'm very happy with the turbosmart. I spin right up to 16 psi when I mash it, and I hold it very well. I threw down and won my first street race the other day, so it's smiles all around as I rib my boy at work here about it. I love the sound, I've had no backfires, shudders, idle issues, or any other evils associated with BOV. The hybrid truly seems to work as best of both worlds so far. My mileage has improved a bit too, as long as I don't get on her. 32 highway is now 34. Glad I got it. The forge is awesome too though, it was one or the other..

[Nokkers3]

I've had the TurboXS Hybrid BoV for about 5 months now and I really like it. It's well constructed and easy to install. It's also not very loud, which some people might like. I haven't used any other BoV/BPV so I can't really compare, but I don't regret buying the TurboXS.

[ericm]

And for those wanting our valve without the sound... just wait.

I'd buy a stock appearing non-leaking BPV that didn't make any wierd noises.

[J-Villa]

why did this thread get so big? this forum is full of bov/bpv threads. just SEARCH

[redwinqs]

I'ts hard to wait, now you have given a hint. Any more info? I like the performace of the Forge, but the tink sound is a bit weird...

+1, anymore info on "waiting"..?

[filphil]

I'ts hard to wait, now you have given a hint. Any more info? I like the performace of the Forge, but the tink sound is a bit weird...

Forge is coming out with a new BPV that doesn't have the PING sound and will sound more like a traditional blow off(for lack of a better word) sound.

[PCspeed3]

Cobb's should be out in a month or so. The other day when I was down there they said they have all the parts for their BPV, they just have to assemble them when they get some time.

[funksilver07]

I love my Forge BPV, with the install of the turbo inlet pipe the sound is more Pssshhh than ping...