IW STi Forum banner

1 - 20 of 160 Posts

·
Indiatr0n in yo IWDPL
Joined
·
8,577 Posts
Discussion Starter #1
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:

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!
 

·
Registered
Joined
·
4,051 Posts
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.
 

·
Registered
Joined
·
4,051 Posts
nandanrp said:
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 ;).

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
 

·
Indiatr0n in yo IWDPL
Joined
·
8,577 Posts
Discussion Starter #7
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.
 

·
Registered
Joined
·
1,562 Posts
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
 

·
Registered
Joined
·
248 Posts
Majin said:
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..:D

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

·
Registered
Joined
·
12 Posts
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
 

·
Registered
Joined
·
248 Posts
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
 

·
Registered
Joined
·
8 Posts
nandanrp said:
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:
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???
 

·
A.X.D.
Joined
·
5,114 Posts
scoobyblu33 said:
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.
 

·
Registered
Joined
·
26 Posts
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?
 

·
Registered
Joined
·
4,051 Posts
Majin said:
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.
 

·
Registered
Joined
·
205 Posts
Thanks for the informative info currently running a Turbo XS BOV but bought the car like that in future will change to a stock one.
 

·
Registered
Joined
·
818 Posts
General question (I have no plans to get a BOV). Besides the sound, why would anybody get a BOV vs. a BPV (both protect against back pressure hitting the turbo)? It just seems to provide no benefit besides turbo longevity (which the BPV has) but screws with your AF ratio... I'm confused. Even with a large(r) turbo, wouldn't a BPV always be preferable?
 

·
Registered
Joined
·
818 Posts
Aren't there higher end BPV's which can handle the increased boost? (keep in mind I know almost nothing about cars) Or, is it that a BPV by design shouldn't be recirculating the increased (I'm guessing 20-25lb+ range?) boost back into the system and instead venting to atmosphere instead...
 

·
Registered
Joined
·
21 Posts
unrequited said:
Aren't there higher end BPV's which can handle the increased boost? (keep in mind I know almost nothing about cars) Or, is it that a BPV by design shouldn't be recirculating the increased (I'm guessing 20-25lb+ range?) boost back into the system and instead venting to atmosphere instead...

turboxs just release a new bov for sti , which come with recriculating . i think :D
 
1 - 20 of 160 Posts
Top