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SCCA_MS3
02-03-2009, 12:50 PM
Looking into getting a BOV and would like to know if there are any actual performance benefits to the addition, or if it is more for aesthetics and makes the turbo sound more prominent? Any input would be appreciated. Thanks.

Trader
02-03-2009, 01:25 PM
If anybody has any DH logs of a before and after that they could post. That would be helpful as well.

lestat13
02-03-2009, 01:40 PM
I was flipping through one of the car magazines yesterday while my girl grabbed a coffee in the bookstore, dyno tested a new evo x with a new bpv and a new bov and dyno'd a clear performance loss in the bov. Assuming since the new evo and our cars rely on mafs, this would be the same story with our cars. I will def tell you after having many bov setups on this car, you will lose a bit of power.

cjms3
02-04-2009, 02:20 AM
i have a forge BPV and noticed a good gain... but yeah in VTA you should notice a tiny loss..

fatti03msp
02-04-2009, 10:52 AM
but i think that problem would go away if you relocate the MAF. Im not sure if you speed3 guys have this as an option. But i know for the MSP we would move the MAF to be after the BOV so the MAF is reading all the air that is goign to the engine.

jred321
02-04-2009, 11:01 AM
the only time an upgraded bov (or bpv, bpv = recirc bov on this forum) will show a performance gain is if you are currently pushing more pressure than your existing valve can handle. this will cause it to leak and the air the engine thinks its getting won't make it there. a better bov would fix that problem.

if you dump air out of the closed system that has already been metered and expect to not have any adverse effects then you're a moron. after the air passes the MAF in this system it enters into a closed system.

a bov's function is to alleviate pressure that builds up when the throttle plate is closed so that the turbo doesn't have to fight hard to spin and damage itself. that's it. if the one you have is working correctly you will see no performance benefit.

mazdaspeedster3
02-04-2009, 11:07 AM
Hence just upgrading your BPV to a Forge or equivalent (full recirc BPV) if and when you notice (DH would help) not holding boost pressures proving a leaky BPV. I can tell you that with the stock BPV my boost would drop dramatically sometimes all the way down to 11psi almost immediately after hitting max. Now with the forge I can hold 15-14 psi with no problem to 5200 RPM.

JDM-P5
02-04-2009, 11:09 AM
Of course...I have a Miata. It sounds cool though.

Sorry...I am of no help.

Abilor
02-04-2009, 12:04 PM
If anybody has any DH logs of a before and after that they could post. That would be helpful as well.

I can do that prior to my install tonight. Logs of what?

Abilor
02-04-2009, 12:06 PM
Besides boost, I mean.

john blutarski
02-04-2009, 01:02 PM
Besides boost, I mean.

If you can, log your fuel trims too. I read a thread somewhere of a BPV/BOV's possible effects on fuel trims.

SleepyMSP
02-04-2009, 01:33 PM
the only time an upgraded bov (or bpv, bpv = recirc bov on this forum) will show a performance gain is if you are currently pushing more pressure than your existing valve can handle. this will cause it to leak and the air the engine thinks its getting won't make it there. a better bov would fix that problem.

if you dump air out of the closed system that has already been metered and expect to not have any adverse effects then you're a moron. after the air passes the MAF in this system it enters into a closed system.

a bov's function is to alleviate pressure that builds up when the throttle plate is closed so that the turbo doesn't have to fight hard to spin and damage itself. that's it. if the one you have is working correctly you will see no performance benefit.


I totally agree with this, at best you will not have a performance gain (rated in HP). But there is a benefit to be had for a properly functioning BPV/BOV, for all of us with the gobbler. When you kill the turkey this means that the compressor is not being stopped by the air trapped by the throttle plate closing and thus when you shift and then step on it again your spool is sitting there waiting for you, you don't have to experience lag again....

Wagonbacker9
02-04-2009, 01:46 PM
I totally agree with this, at best you will not have a performance gain (rated in HP). But there is a benefit to be had for a properly functioning BPV/BOV, for all of us with the gobbler. When you kill the turkey this means that the compressor is not being stopped by the air trapped by the throttle plate closing and thus when you shift and then step on it again your spool is sitting there waiting for you, you don't have to experience lag again....

not to mention that the turbo will last longer.

Your best bet is to recirc a good quality aftermarket bov. Stronger than stock, but functions the same way. VTA is a comprimise of performance and long term durability for styling, unless you relocate your MAF as mentioned earlier... And in doing that, some are concearned with having the MAF on a boosted tube ruining the MAF eventually. Others have done it for years without issue...

Wagonbacker9
02-04-2009, 01:48 PM
buy me: http://www.mazdas247.com/forum/showthread.php?t=123732685

SleepyMSP
02-04-2009, 01:54 PM
also note that some piggy back EMS's don't like a reloc-ed MAF (i.e. unichip). Having the MAF on the pressurized side will work for X amount of time but it will fail sooner than on the un-pressurized side

MM BOOST
02-04-2009, 01:58 PM
buy me: http://www.mazdas247.com/forum/showthread.php?t=123732685

PM already sent, just waiting on him to reply :)

Wagonbacker9
02-04-2009, 01:59 PM
also note that some piggy back EMS's don't like a reloc-ed MAF (i.e. unichip). Having the MAF on the pressurized side will work for X amount of time but it will fail sooner than on the un-pressurized side

I have to think there is another factor involved with failure than time. Maybe guys running it relocated aren't filtering intake charge as well? something? idk

Trader
02-04-2009, 02:36 PM
the only time an upgraded bov (or bpv, bpv = recirc bov on this forum) will show a performance gain is if you are currently pushing more pressure than your existing valve can handle. this will cause it to leak and the air the engine thinks its getting won't make it there. a better bov would fix that problem.

if you dump air out of the closed system that has already been metered and expect to not have any adverse effects then you're a moron. after the air passes the MAF in this system it enters into a closed system.

a bov's function is to alleviate pressure that builds up when the throttle plate is closed so that the turbo doesn't have to fight hard to spin and damage itself. that's it. if the one you have is working correctly you will see no performance benefit.

Agreed.

I think that this question is better asked by saying the following:

At what psi does the stock MS3 BPV start leaking?

If you are boosting above this point you are loosing performance, because your turbo has to pump harder to keep the same psi level. Therby causing more heat in the intake and more restriction on exhaust gas flow to create the same boost pressure. Your VE of your engine would be less.

If the stock BOV holds the boost you are using there is no performance to be gained.

So at what PSI does the stock valve start leaking? And any data or DH logs that show this?

Abilor
02-04-2009, 02:51 PM
Wow. Can't wait to log. Might have to escape from work early...

neox.286
02-04-2009, 02:58 PM
I totally agree with this, at best you will not have a performance gain (rated in HP). But there is a benefit to be had for a properly functioning BPV/BOV, for all of us with the gobbler. When you kill the turkey this means that the compressor is not being stopped by the air trapped by the throttle plate closing and thus when you shift and then step on it again your spool is sitting there waiting for you, you don't have to experience lag again....

*sigh* the msp has a similar sound to compressor surge but it is due to the abnormally small outlet on the bpv and small inlet on the intake, that's it....combine that with the type of bpv it is and you get that sound

try getting a larger outlet bpv like the bosch, then get a larger inlet welded on your intake...the sound will go away

BUT since there are a lot of people who still don't believe this, and this is for the speed3 guys not the msp guys, [/threadjack]


Jred is completely correct

SCCA_MS3
02-04-2009, 03:15 PM
Great responses everyone.

So i am getting the impression that unless i have done enough work to the motor/turbo to produce a higher psi, i do not need to upgrade this?

jred321
02-04-2009, 03:21 PM
So i am getting the impression that unless i have done enough work to the motor/turbo to produce a higher psi, i do not need to upgrade this?
not necessarily. depends on how well the system was designed in the first place. while a stock valve shouldn't leak at stock pressures that isn't necessarily true.

neox.286
02-04-2009, 03:31 PM
yea, I wouldn't trust the stock bpv to handle the speed3's boost levels....upgrading to another bpv may show gains, but that's really really iffy and assuming a lot

mazdaspeedster3
02-04-2009, 03:39 PM
I dont think it is presumptuiss at all. I dont log on my DH but have seen boost levels stay more consistent with the Forge than with the Stock. The stock just wont hold the pressure across the RPM range. The Forge does. If your stock isnt leaking than obviously an upgrade isnt doing you any good other than sound. If you can tell it is leaking then it will, cut and dry.

neox.286
02-04-2009, 03:43 PM
^^^
by assuming a lot meant I don't know anything about the bpv in the speed3 lol, so I was assuming a lot

but yea, if you are able to see the boost levels affected in a positive way then the stocker is definately not able to handle the speed3's boost levels

Sphincter
02-04-2009, 03:53 PM
As some have mentioned, with BOV running VTA you would loose a little power, Would this also happen if you ran something like Turbosmart 50/50, going 50 recirc and 50 vta?

neox.286
02-04-2009, 03:55 PM
yes, any kind of air you are taking out of the system post the MAF sensor will result in some kind of a powerloss, even a 50/50 setup

this is why rally cars run with no bov/bpv at all, they just replace the turbo when the turbo fails....maximum power over short time periods

Wagonbacker9
02-04-2009, 04:14 PM
yes, any kind of AIR you are taking out of the system post the MAF sensor will result in some kind of a powerloss, even a 50/50 setup

edit for clarity....

AllLostThings
02-04-2009, 04:38 PM
It was the third mod I did. Racepipe, CAI, and the BOV. I didn't notice a thing but the diffrent noise which I like. However I got mine used from a member on this forum for $75 shipped so I wasn't exactly breaking the bank and getting nothing for it. I'm happy with what it does.

jred321
02-04-2009, 04:52 PM
As some have mentioned, with BOV running VTA you would loose a little power, Would this also happen if you ran something like Turbosmart 50/50, going 50 recirc and 50 vta?
think about it this way. your MAF counts air particles. it knows at any given moment how many pieces of air are in the system. it adjusts fuel accordingly. if you remove some of the air it has no way of knowing how much you've removed so it will not adjust the fuel. so you'll run rich. that means your power will be less.

neox.286
02-04-2009, 04:53 PM
edit for clarity....

lol, I'm dyslexic I think...

Abilor
02-04-2009, 04:55 PM
How about 80/20?

neox.286
02-04-2009, 05:01 PM
think about it this way. your MAF counts air particles. it knows at any given moment how many pieces of air are in the system. it adjusts fuel accordingly. if you remove some of the air it has no way of knowing how much you've removed so it will not adjust the fuel. so you'll run rich. that means your power will be less.

exactly

I've seen first hand the difference from VTA to recirc twice now....with dyno proven results

run recirc, don't vent any air off....the only advantage is sound

Mistersix
02-07-2009, 09:48 PM
after i hit full boost, boost slowly drops and drops. by the time it hits 11, 12 lbs its time to shift. does this mean my stock bpv leaks. i'm assuming so.
also this is read of my prosport gauge.

neox.286
02-07-2009, 11:22 PM
That could be the bpv or it could be the way the stock ecu is tuned since there is gear specific boost control stock

I'm guessing it's the bpv though