bov vs dv comparative

a7med606 · 12-08-2011, 07:13 PM

what is the difference between blow off valve and diverter valves ??

the only thing i know that is the diverter valve is deiverting the air back into the air intake

and i know that in general the car comes rich when the bov start it works to take out the air

and whats better for the 335i ??

i made a search in the forum and i didn't find what i need

ttbmer · 12-08-2011, 07:26 PM

Is all the same, just a matter of preference. U want a BOV sound disconnect the front Dv from the IC piping going into the charge pipe and there u go.

a7med606 · 12-08-2011, 07:28 PM

only sound difference ??
there is no difference in the tune ???

Jeff@TopGearSolutions · 12-08-2011, 07:32 PM

No difference in performance or tuning. The stock DV tend to leak which is why people upgrade. Other people upgrade to BOV simply for the sound, however, the purpose is to relieve and hold pressure better then stock DV can.

a7med606 · 12-08-2011, 07:41 PM

i upgraded mine to he turbo smart diverters not the dual port
but the sound is not loud enough for me
if i disconnected the pipes will it be louder ??
and there is no effects if i disconnected them ?

ttbmer · 12-08-2011, 07:44 PM

Quote:

Originally Posted by Jeff@topgearsolutions

No difference in performance or tuning. The stock DV tend to leak which is why people upgrade. Other people upgrade to BOV simply for the sound, however, the purpose is to relieve and hold pressure better then stock DV can.

Jeff does anyone know, how much psi can the stock DVs handle. Hard prof.
How to test is DVs at leaking

Royal Flush · 12-08-2011, 09:06 PM

Quote:

Originally Posted by ttbmer

Jeff does anyone know, how much psi can the stock DVs handle. Hard prof.
How to test is DVs at leaking

IDK about specific tests and proof, but several members have no problem running low 20s psi on stock DVs.

nitehawk · 12-08-2011, 09:14 PM

Quote:

Originally Posted by ttbmer

Jeff does anyone know, how much psi can the stock DVs handle. Hard prof.
How to test is DVs at leaking

Not sure if you this on the other DV thread:

http://www.n54tech.com/forums/showthread.php?t=109

PINeely · 12-08-2011, 09:16 PM

BOV: Vents to atmosphere, makes a cool whoosh sound that some like and some hate.
DVs: Recirculate air into charge pipe instead of venting it.

BostonMike · 12-08-2011, 10:34 PM

Quote:

Originally Posted by Jeff@topgearsolutions

No difference in performance or tuning. The stock DV tend to leak which is why people upgrade. Other people upgrade to BOV simply for the sound, however, the purpose is to relieve and hold pressure better then stock DV can.

What does that mean "to relieve and hold pressure better"? It is my understanding that a BOV releases pressure. A diverter valve recirculates (holds) it.
The reason you have a diverter valve in the first place is to keep the pressure between shifts. If you "blow it off" the turbos take longer to spool up and create more pressure.
If you want to test this, install a boost gauge. The boost gauge will also show you if your diverters a leaking.
The BOV, however, sounds wicked cool! OP if you are one that likes bleeding edge performance, keep your diverter valves and spend your money on a boost gauge. If you like the cool sound and flashy look get a nicely built BOV.

Brey335i · 12-08-2011, 10:48 PM

It means to relieve when it's supposed to and hold it in between (not leaking)

BostonMike · 12-08-2011, 10:57 PM

Oh, Ok. I see what he meant now. Hold it before the shift.

TBolts10 · 12-08-2011, 11:36 PM

Quote:

Originally Posted by ttbmer

Is all the same, just a matter of preference. U want a BOV sound disconnect the front Dv from the IC piping going into the charge pipe and there u go.

Any side effects of doing this?

PINeely · 12-08-2011, 11:51 PM

Quote:

Originally Posted by tyler20c

Any side effects of doing this?

The dump line is never under vacuum so nope, just plug the holes in the DV inlets and you are good to go. Of course there are people on here who like to spend money on expensive parts and swear up and down that your engine will detonate as soon as you do this.

Zeph · 12-09-2011, 07:29 AM

You can keep hot air (recycle) or get rid of it. The sound is a personal choice.

NoQuarter · 12-09-2011, 07:33 AM

There is another issue with respect to Meth users.

Switching to a BOV can eject meth mixture into engine compartment correct?

Brey335i · 12-09-2011, 09:35 AM

Quote:

Originally Posted by NoQuarter

There is another issue with respect to Meth users.

Switching to a BOV can eject meth mixture into engine compartment correct?

It helps cool the engine compartment. Thus providing better reliability

/ troll physics

Lulz_M3 · 12-09-2011, 10:04 AM

Quote:

Originally Posted by BostonMike

If you "blow it off" the turbos take longer to spool up and create more pressure.

Incorrect, the DV's dump the air back into the pre-turbo intake tract. Any additional spool time would be hardly noticeable.

Quote:

Originally Posted by BostonMike

If you want to test this, install a boost gauge. The boost gauge will also show you if your diverters a leaking.

A boost gauge wont show you boost leak unless it is MASSIVE. You would get a CEL for boost target way before you would need to go this route. If you can log waste gate duty cycle you could identify a small leak much easier...

Syndicategt · 12-09-2011, 10:35 AM

Quote:

Originally Posted by NoQuarter

There is another issue with respect to Meth users.

Switching to a BOV can eject meth mixture into engine compartment correct?

Incorrect. When spryaing (either based off of duty cycle or boost) your BOV should be closed, unless it's not working properly. When you let off the gas to shift, or brake, you may have a miniscule amount of meth be released out the BOV , but the amount would be so little it will not cause any harm. Watch DSBJ's videos of flame testing different mixtures, even with a direct flame, the meth did combust with 50/50.

OP - our cars have TMAP sensors, so a BOV will not effect anything.

PINeely · 12-09-2011, 11:07 AM

^^^ +1, and any meth vented to the engine is just water and alcohol anyway, it'll evaporate instantly.

12-08-2011, 07:13 PM	#1
a7med606 First Lieutenant 41 Rep 307 Posts Drives: 1 ///M + F80 M3 Join Date: Nov 2011 Location: bahrain iTrader: (0)	bov vs dv comparative what is the difference between blow off valve and diverter valves ?? the only thing i know that is the diverter valve is deiverting the air back into the air intake and i know that in general the car comes rich when the bov start it works to take out the air and whats better for the 335i ?? i made a search in the forum and i didn't find what i need
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12-08-2011, 07:26 PM	#2
ttbmer Lieutenant Colonel 68 Rep 1,943 Posts Drives: space gray on black 07 335i Join Date: Jul 2010 Location: las Vegas nv iTrader: (15)	Is all the same, just a matter of preference. U want a BOV sound disconnect the front Dv from the IC piping going into the charge pipe and there u go. __________________ PROCEDE, PWM Vishnu Kit, AR catless DP, BMS DCI, Helix IC, P3 gauge, 25% window tint, mattblack window trim, mattblack roof wrapped. Vorstainer CSL trunk, CF wrapped interior, 18'' Forgestar F14 Matt black, quaife LSD, M3 suspension bits, Mtech front bumper). http://www.youtube.com/watch?v=b8JIB8C8HDA
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12-08-2011, 07:28 PM	#3
a7med606 First Lieutenant 41 Rep 307 Posts Drives: 1 ///M + F80 M3 Join Date: Nov 2011 Location: bahrain iTrader: (0)	only sound difference ?? there is no difference in the tune ???
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12-08-2011, 07:32 PM	#4
Jeff@TopGearSolutions 3441 Rep 79,211 Posts Drives: C6 Z06, 09 335i, 10 335xi Join Date: Dec 2008 Location: www.TopGearSolutions.com iTrader: (37)	No difference in performance or tuning. The stock DV tend to leak which is why people upgrade. Other people upgrade to BOV simply for the sound, however, the purpose is to relieve and hold pressure better then stock DV can.
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12-08-2011, 07:41 PM	#5
a7med606 First Lieutenant 41 Rep 307 Posts Drives: 1 ///M + F80 M3 Join Date: Nov 2011 Location: bahrain iTrader: (0)	i upgraded mine to he turbo smart diverters not the dual port but the sound is not loud enough for me if i disconnected the pipes will it be louder ?? and there is no effects if i disconnected them ?
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12-08-2011, 09:16 PM	#9
PINeely Lieutenant Colonel 1086 Rep 1,912 Posts Drives: 2013 535i, 2015 Tundra 1794 Join Date: Jul 2009 Location: Jackson, MS iTrader: (2)	BOV: Vents to atmosphere, makes a cool whoosh sound that some like and some hate. DVs: Recirculate air into charge pipe instead of venting it.
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12-08-2011, 10:48 PM	#11
Brey335i Banned 112 Rep 4,771 Posts Drives: e46 ///M3 Join Date: Oct 2009 Location: Austin, TX iTrader: (11)	It means to relieve when it's supposed to and hold it in between (not leaking)
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12-08-2011, 10:57 PM	#12
BostonMike Second Lieutenant 30 Rep 238 Posts Drives: Black 335 Join Date: Jul 2011 Location: Methuen iTrader: (1) Garage List 2017 M4 [0.00]	Oh, Ok. I see what he meant now. Hold it before the shift.
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12-09-2011, 07:29 AM	#15
Zeph Major 27 Rep 1,410 Posts Drives: 2008 E92 335i 6MT SGM CR/BD Join Date: Jul 2008 Location: Southeast USA iTrader: (0)	You can keep hot air (recycle) or get rid of it. The sound is a personal choice.
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12-09-2011, 07:33 AM	#16
NoQuarter Captain 166 Rep 906 Posts Drives: 2008 535xi / 2011 Z4 35Is Join Date: Jan 2011 Location: Indiana iTrader: (0) Garage List 2018 BMW X2 [0.00] 2008 535xi [0.00] 2011 Z4 35is [0.00]	There is another issue with respect to Meth users. Switching to a BOV can eject meth mixture into engine compartment correct?
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12-09-2011, 11:07 AM	#20
PINeely Lieutenant Colonel 1086 Rep 1,912 Posts Drives: 2013 535i, 2015 Tundra 1794 Join Date: Jul 2009 Location: Jackson, MS iTrader: (2)	^^^ +1, and any meth vented to the engine is just water and alcohol anyway, it'll evaporate instantly.
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