BOV FAQ: The REAL dirt on BOVs. Ups AND downs. Lets dispell some myths.

[Bov_Rider]

good info!

personally, I love the sound of the BOV. I was still a kid when i saw the GC then the bugeye with that sound. Since that time and I wanted to own a Suby and now I do so I dont care what others think of that sound. I am paying for my stuff and my car at the end.

Waiting my HKS SuperSequential BOV.

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[Shamwow11]

Originally Posted by Bov_Rider

good info!

personally, I love the sound of the BOV. I was still a kid when i saw the GC then the bugeye with that sound. Since that time and I wanted to own a Suby and now I do so I dont care what others think of that sound. I am paying for my stuff and my car at the end.

Waiting my HKS SuperSequential BOV.

Don't get the hks ssqv. I run it on my Subie now and I can't wait to get rid of it. It makes my car run terribly and tends to hesitate on throttle. The noise is also incredibly annoying and high pitched compared to a tial BOV or GFB BOV. If you're gonna pay all the money and enjoy a good BOV sound and also want a BPV, GFB makes hybrid BOVs like the deceptor pro where you can choose fully VTA, 50/50, or fully recirc.

[Bov_Rider]

Originally Posted by Shamwow11

Don't get the hks ssqv. I run it on my Subie now and I can't wait to get rid of it. It makes my car run terribly and tends to hesitate on throttle. The noise is also incredibly annoying and high pitched compared to a tial BOV or GFB BOV. If you're gonna pay all the money and enjoy a good BOV sound and also want a BPV, GFB makes hybrid BOVs like the deceptor pro where you can choose fully VTA, 50/50, or fully recirc.

thanks bro for the advice but like you, others telling that they r running with HKS SSQ for years with no issue but i like the way a GFB is usable in three modes.

[Shamwow11]

Originally Posted by Bov_Rider

thanks bro for the advice but like you, others telling that they r running with HKS SSQ for years with no issue but i like the way a GFB is usable in three modes.

No problem man! Just throwin my two cents! If you haven't bought one yet. You are more than welcome to buy mine. It's in great condition. Just not very fond of it.

[noonagon]

You guys make my face brain hurt.

From my research and from running a 50/50 and VTA on my car (even a crushed stocker would not hold my only 26psi), there is zero ill effect. If you have cats and run a VTA for 8 years you might cause premature wear on them. For the amount of time your car runs rich ( I will log it Friday) you might actually cool the engine a little lol. Running rich is not the problem imho, running lean is a problem and a VTA, as long as it functions properly, will not cause the car to run lean. I will log a 3-4-5 pull and regular city driving with a Turbosmart supersonic VTA and post the AFR results!

[amalgrover]

sooo...then you are saying you agree with the OP...which is pretty much what 99% of the people who posted in here said...i am confused about what exactly is making your "face brain" hurt...

[soberpoet]

according to my understanding venting boost back to intake also helps with turbo spool during shifts...
granted the plumbing is not routed all funky, but i dont know they sound cool thats about it in my opinion

[noonagon]

Originally Posted by amalgrover

sooo...then you are saying you agree with the OP...which is pretty much what 99% of the people who posted in here said...i am confused about what exactly is making your "face brain" hurt...

Lol, what is making my head hurt is the large percentage of folks that say VTA is bad. I agree with the op but it seems the last few pages of posts went to say that bpv is the only way to go.

Doesn't matter, I will post some logs and we will see some real proof lol

[amalgrover]

i don't feel that a VTA bov is going to hurt anything when properly installed and adjusted, but, like i said in response to the person a few posts back, the vehicle was DEFINITELY not designed for a VTA bov. so the 100% "proper" way is with a bpv.


for the record, i run a VTA bov on my daily driven bugeye, and have for the last 4 years, without any issues.


also, a log may not be able to capture the full extent of the effects of a VTA bov because alot of the time logs have a hard time even picking up tip in, but i agree with you that a log is probably a good thing to post up.

[PleiadesSTi]

My Perrin recirculating BPV for my 09 wrx sounds cool and works as intended.

[Street_EJ257]

For those of you just looking for that Tssss or Chufff sound when you come off the boost, the easiest, cheapest (free) way to get you 70% of the way there:

Remove the white plastic resonator from your factory intake airbox. It will amplify the sound of your stock recirculating BPV by close to a factor of 10, sounding like a slightly muted VTA BOV.

Advantages (over a VTA BOV):

*FREE upgrade you can do in your garage with very close to 0 skill and only basic tools.
*Does not cause any performance problems.
*Does not require a Speed Density pro-tune to function correctly, since all the air metered by the MAF sensor is eventually used up by your engine.
*Your OEM BPV doesn't leak (if you are getting a turbocharger capable of boosting high enough to cause a leaky stock bpv you will need a protune anyway)
*You can hear the whine of the turbo compressor clearly.
*You can hear the WHOOSH of air being sucked into your intake under boost.
*The rest of us won't be mocking you for making your car WORSE just to hear it breathe.
*Unlike most aftermarket intakes, you won't need to reflash your ECU for it to work properly.

Disadvantages:

*Not quite as loud as a VTA (though for many people it's loud enough)
*If you are eager to spend your hard earned money, or charge up your credit card for parts you can't really afford (most of us have been there), installing a ~$250.00 TiAL or equivalent quality BOV, and getting a high quality ~$500.00 Speed Density (MAP Based) pro tune will net you considerable power gains (from the tune, not the valve) without running rich, in addition to having a louder noise - whereas removing your resonator will not make a difference in power.

While running rich is not going to blow up your engine, it will result in less power at partial throttle, and wasted gasoline. A "Speed Density" tune uses information from your MAP (manifold air pressure) and temperature sensors to infer mass flow rate of air into your engine. This allows your ECU to account for the air vented to the atmosphere by your aftermarket BOV.

Going to a full VTA BOV without a Speed Density tune is like removing your car's hood to save weight, without replacing it with a lighter CF one. I mean... YES, removing your hood altogether WOULD save weight, BUT it causes other problems - and announces to the world around you that you have no idea what you are doing.

Whatever mods or parts you choose to bolt onto your vehicle, know how they will affect other systems and why - and consider all your options.

___________________

A lot of folks who buy and install VTA BOV's erroneously see it as a good starter upgrade without needing a protune. Please don't be "that guy". Try the simple solution first, and if that doesn't satisfy, at least do it right and get a good SD protune to go with the valve.

-Josh

[Juan_STi]

is it true you need to tune your sti after you get a bov?

[akracer609]

Lol I was wondering what bov meant...figured it out half way through that it meant blow off valve

[r95x]

#4 LOL! Good one.

[sc00by4life]

Originally Posted by Juan_STi

is it true you need to tune your sti after you get a bov?

there is absolutely no way to tune for it.

[amalgrover]

Originally Posted by Street_EJ257

While running rich is not going to blow up your engine, it will result in less power at partial throttle, and wasted gasoline.

I agree with everything you posted except for this.

The bov only opens (or at least is supposed to only open) during throttle lift, and last time I checked, the power output has never mattered here.

Also, how long does it take your valve to relieve pressure? Last time I watched my boost gauge while the valve was opening, it literally was almost instant. Once the pressure is relieved, the valve closes again. If you watch on a wideband, you can see this actually happen. Now, my point is, how much gas are you really wasting by going rich for that 1/4-1/8 of a second? My guess would be almost an unmeasureable amount.

For example, my car with a VTA bov, 80mm KSTech mega maf, 1250cc injectors, evap deleted, tgv's deleted, and E85 was still getting 16-17mpg city and 22-23mpg hwy. On 93oct it was getting about 1-2mpg more on both city and hwy...and last I looked, that was pretty darn close to a stock turbo 2.5L's fuel economy...so I can't be wasting THAT much gas.

[randomtasks]

Nice reply amalgrover. To sum it up, running with an aftermarket (unless you has to change ur bpv) aint a good idea. Apparently the hybrid ones are "less" harmful

[amalgrover]

Originally Posted by randomtasks

Nice reply amalgrover. To sum it up, running with an aftermarket (unless you has to change ur bpv) aint a good idea. Apparently the hybrid ones are "less" harmful

...That's not what I said at all...

[goose247]

Davenow! My 04 forester xt. Has a turboXS BOV and rotated red turbo. List of everything else is to long. But I'm starting to think my BOV is leaking or is not closing or opening properly as I am getting a weird spike in rpms after coming out of even small boost to a stop. It revs up to 15k then down then usual spikes up and down to 22k before it settles to idle. Would u say BOV or something else?

[luan87us]

Originally Posted by Street_EJ257

For those of you just looking for that Tssss or Chufff sound when you come off the boost, the easiest, cheapest (free) way to get you 70% of the way there:

Remove the white plastic resonator from your factory intake airbox. It will amplify the sound of your stock recirculating BPV by close to a factor of 10, sounding like a slightly muted VTA BOV.

-Josh

I think I might look into this. As long as there is no performance decrease I'm all for it.

[jthatch12]

Originally Posted by luan87us

I think I might look into this. As long as there is no performance decrease I'm all for it.

I think he's referring to a snorkus delete. It does amplify the sounds and will not hurt performance.

[luan87us]

Originally Posted by jthatch12

I think he's referring to a snorkus delete. It does amplify the sounds and will not hurt performance.

Any idea if it's the same on 2013 wrx?

[jthatch12]

Originally Posted by luan87us

Any idea if it's the same on 2013 wrx?

Should be. The snorkus' main job is to muffle the sound of the air intake. So removing it does enhance the sound.

[a3ng25]

This was a good one. I had heard the rumors of bovs making you run rich and it being terrible for the car. But this makes sense. I like the sound but im not sure its worth the $. And Im not really planning on running too much above stock.

[patrickrobare]

Originally Posted by luan87us

Any idea if it's the same on 2013 wrx?

their is none on a 2012+ all you can really do is get a intake.