Read this before you create a new thread about BOVs (Blow-off valves)

**nandanrp** · 03-20-2006, 09:07 PM

BOVs = Blow Off Valves. The STi (stock) uses a BPV (Bypass Valve) which is more than adequate for the boost levels produced by the stock turbo. BOVs can lead to your stock STi running poorly and/or with reduced power output due to running excessively rich. On a stock turbo, their only real use is to make sounds.

This topic has been repeated soooooo many times that you might want to take a look through these threads before you decide to create a new BOV thread:

BOV on 06 STI (closed)
Another CLOSED bov thread...... (closed)
Bov??? (closed)
BOV Question
bov's
BOV question (closed)
Will a BOV mess up my STI???
yes another bov question (closed)

You can see that we have closed more than half of these recent BOV threads. Please be sure to read through these, use the search (because there are MANY more threads than these seven), and if your question has not been answered after all of this...then *think* about creating a new thread

Enjoy your stay at IWSTI!

Rootus · 03-22-2006, 07:52 AM

The only problem is that most of those threads are filled with "it sucks" type of comments, or inaccurate statements like "it will make your car run rich", etc. Heck, even your own post says that. IMO what is needed is a definitive description of the function of the BPV/BOV, along with actual real world impact from running an atmospheric BOV.

**nandanrp** · 03-22-2006, 07:56 AM

That would be fantastic. If you are willing to write it, I'll be happy to edit my post accordingly

***Majin*** · 03-22-2006, 08:01 AM

with a non recirculating venting valve, your car will run rich between shifts

Rootus · 03-22-2006, 08:41 AM

Quote:

Originally Posted by nandanrp

That would be fantastic. If you are willing to write it, I'll be happy to edit my post accordingly

I would be happy to put together a first draft. I will let you know

.

Quote:

with a non recirculating venting valve, your car will run rich between shifts

A good point to include. As well as the counterpoint -- the engine will run rich between shifts even with a BPV. What is debatable is whether there is a significant difference, or if that difference causes any problems that last longer than the gap between shifts.

Dave

**Siegel Racing** · 03-26-2006, 08:38 AM

Does this help?

http://www.siegelracing.com/bov.htm

SS

**nandanrp** · 03-26-2006, 10:09 AM

Cool Scott, thanks for that

Please correct me if I'm wrong, but the turbo stays spooled with a recirc valve or BOV because there is no compressor surge (which would be caused by the air already in the system hitting the turbine). The important fact to note is the richness condition - that's the real difference between the two.

**Siegel Racing** · 03-26-2006, 03:20 PM

With a recirc the turbo blows in a loop, the air comes back around and goes through it again. With a BOV it only gets to "blow out" once....

They both prevent compressor stall, but the recirc helps keep it spooled more.

SS

FujiApples · 04-25-2006, 01:41 PM

Quote:

Originally Posted by Majin

with a non recirculating venting valve, your car will run rich between shifts

haha thats everything you need to kno about BOV on an STi right there..

and i disagree with teh it sucks thing.. so yea i get some lag between shifts.. but its too small to worry about

jrmiller33 · 04-25-2006, 06:43 PM

wow no body gets it the atmospheric bov's dont work on sti's is that sti's are MAF cars there for if you vent your bov your venting metered air that your ecu has already supplied fuel for. for all of you who have aftermarket fuel manage ment the sti is equipped with a MAP sensor switch to speed density and the car will run fine

FujiApples · 04-25-2006, 06:57 PM

haha u kno what i think it is... some people seriously just dont know thats true... but a lot of people (me being one of em) know of all the bad things and why BOV just aren't good. but get em for the sound... imo the power loss is too little to matter to me.. plus ill be switching to MAP eventually anyways.. so its a temporary thing

scoobyblu33 · 05-10-2006, 05:30 PM

Quote:

Originally Posted by nandanrp

BOVs = Blow Off Valves. The STi (stock) uses a BPV (Bypass Valve) which is more than adequate for the boost levels produced by the stock turbo. BOVs can lead to your stock STi running poorly and/or with reduced power output due to running excessively rich. On a stock turbo, their only real use is to make sounds.

This topic has been repeated soooooo many times that you might want to take a look through these threads before you decide to create a new BOV thread:

BOV on 06 STI (closed)
Another CLOSED bov thread...... (closed)
Bov??? (closed)
BOV Question
bov's
BOV question (closed)
Will a BOV mess up my STI???
yes another bov question (closed)

You can see that we have closed more than half of these recent BOV threads. Please be sure to read through these, use the search (because there are MANY more threads than these seven), and if your question has not been answered after all of this...then *think* about creating a new thread

Enjoy your stay at IWSTI!

does this also apply to my 06 STI which i have the whole intake side of the turbo aftermarket(CAI & inlet pipe) and i am getting a turbo back exh. and header and also having it tuned on the dyno? won't a bov help with quicker spool up of my stock turbo???

***Majin*** · 05-10-2006, 06:46 PM

Quote:

Originally Posted by scoobyblu33

does this also apply to my 06 STI which i have the whole intake side of the turbo aftermarket(CAI & inlet pipe) and i am getting a turbo back exh. and header and also having it tuned on the dyno? won't a bov help with quicker spool up of my stock turbo???

yes this applies to the 06 - no a BOV won't help with spooling. it definitely sounds cool, but besides that nothing else is good about it - at least for the stock turbo.

RyanE720 · 05-24-2006, 07:41 PM

i believe that greddy's type s and type rs are able to be recircualted, would that be better then venting to the atmosphere with say an HKS SSQV? i want a BOV but im contemplating on whether its worth it or not? opinions anybody? or recomendations? whats popular, and does anybody have vid/sound clip of how it sounds?

Rootus · 05-25-2006, 03:34 AM

Quote:

Originally Posted by Majin

at least for the stock turbo.

It has nothing to do with the size of the turbo or whether or not it is stock. A BOV can cause problems when it vents to atmosphere during part throttle and is used in a draw-through MAF system like the stock setup. No matter what size turbo you go with, if you want to vent to atmosphere at part throttle, you will have to convert to a blow-through MAF.

03-20-2006, 09:07 PM	#1
nandanrp Indiatr0n in yo IWDPL Car: 05FTW OBP STi Fav Mod: Brum Brum Location: downtown Chicago Posts: 48,830 Join Date: Jun 2004 Trader Rating: (11)	Read this before you create a new thread about BOVs (Blow-off valves) BOVs = Blow Off Valves. The STi (stock) uses a BPV (Bypass Valve) which is more than adequate for the boost levels produced by the stock turbo. BOVs can lead to your stock STi running poorly and/or with reduced power output due to running excessively rich. On a stock turbo, their only real use is to make sounds. This topic has been repeated soooooo many times that you might want to take a look through these threads before you decide to create a new BOV thread: BOV on 06 STI (closed) Another CLOSED bov thread...... (closed) Bov??? (closed) BOV Question bov's BOV question (closed) Will a BOV mess up my STI??? yes another bov question (closed) You can see that we have closed more than half of these recent BOV threads. Please be sure to read through these, use the search (because there are MANY more threads than these seven), and if your question has not been answered after all of this...then think about creating a new thread Enjoy your stay at IWSTI! This ad is not endorsed by this member. Please register or login to hide this ad.

03-22-2006, 07:52 AM	#2
Rootus S204 Racer Location: Mahan, OR Posts: 2,904 Join Date: Sep 2005 Trader Rating: (1)	The only problem is that most of those threads are filled with "it sucks" type of comments, or inaccurate statements like "it will make your car run rich", etc. Heck, even your own post says that. IMO what is needed is a definitive description of the function of the BPV/BOV, along with actual real world impact from running an atmospheric BOV.

03-22-2006, 07:56 AM	#3
nandanrp Indiatr0n in yo IWDPL Car: 05FTW OBP STi Fav Mod: Brum Brum Location: downtown Chicago Posts: 48,830 Join Date: Jun 2004 Trader Rating: (11)	That would be fantastic. If you are willing to write it, I'll be happy to edit my post accordingly

03-22-2006, 08:01 AM	#4
*Majin* A.X.D. Car: 2004 STi Location: LI, NY Posts: 12,792 Join Date: Apr 2004 Trader Rating: (2)	with a non recirculating venting valve, your car will run rich between shifts

03-26-2006, 08:38 AM	#6
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,262 Join Date: Mar 2005 Trader Rating: (2)	Does this help? http://www.siegelracing.com/bov.htm SS

03-26-2006, 10:09 AM	#7
nandanrp Indiatr0n in yo IWDPL Car: 05FTW OBP STi Fav Mod: Brum Brum Location: downtown Chicago Posts: 48,830 Join Date: Jun 2004 Trader Rating: (11)	Cool Scott, thanks for that Please correct me if I'm wrong, but the turbo stays spooled with a recirc valve or BOV because there is no compressor surge (which would be caused by the air already in the system hitting the turbine). The important fact to note is the richness condition - that's the real difference between the two.

03-26-2006, 03:20 PM	#8
Siegel Racing Authorized Vendor Car: Your STi ;) Fav Mod: Everything Location: Atlanta Posts: 1,262 Join Date: Mar 2005 Trader Rating: (2)	With a recirc the turbo blows in a loop, the air comes back around and goes through it again. With a BOV it only gets to "blow out" once.... They both prevent compressor stall, but the recirc helps keep it spooled more. SS

04-25-2006, 06:43 PM	#10
jrmiller33 Amateur STI Driver Car: o4 sti Fav Mod: utec, aps intake tbe, perrin springs hotchkis comp sways Posts: 12 Join Date: Jul 2005 Trader Rating: (0)	wow no body gets it the atmospheric bov's dont work on sti's is that sti's are MAF cars there for if you vent your bov your venting metered air that your ecu has already supplied fuel for. for all of you who have aftermarket fuel manage ment the sti is equipped with a MAP sensor switch to speed density and the car will run fine

04-25-2006, 06:57 PM	#11
FujiApples STI Driver Car: 2008 A4 6MT LOADED Fav Mod: I miss my Subaru... Location: Chino Hills, CA Posts: 254 Join Date: Jul 2005 Trader Rating: (2)	haha u kno what i think it is... some people seriously just dont know thats true... but a lot of people (me being one of em) know of all the bad things and why BOV just aren't good. but get em for the sound... imo the power loss is too little to matter to me.. plus ill be switching to MAP eventually anyways.. so its a temporary thing

05-24-2006, 07:41 PM	#14
RyanE720 Amateur STI Driver Car: 05 STi Aspen wht/gld Fav Mod: buying the car! and DP and Exhaust... Location: Sac CA Posts: 27 Join Date: May 2006 Trader Rating: (0)	i believe that greddy's type s and type rs are able to be recircualted, would that be better then venting to the atmosphere with say an HKS SSQV? i want a BOV but im contemplating on whether its worth it or not? opinions anybody? or recomendations? whats popular, and does anybody have vid/sound clip of how it sounds?