BOV placement

[qrankz]

Where's a good place to put a bov on the intake pipe? What causes turbo cars to stall with a bov installed? I have seen people recirculate the bov, why?

[ryder_23]

Well, i'm offering my late night info, from what i know.

People recirculate, because some cars get screwed up with there Mass Airflow Sensor, and without recirculating, it messes up the computer. (atleast thats what i understand)

As for placement, after the cold side after the intercooler, leading to the intake manifold, atleast thats where i see it most of the time. I believe cars like the STi has it on the intercooler itself. Not sure if its crucial, but wait till morning, and someone will give you 100% proper advice :thumbsup:

[EK 2.0]

As Ryder mentioned...

Depending on what kind of air metering you car uses, will dictate which is the best form of BOV, whether recric-ed, or vented.

As for placement, the best place is usually as close to the throttle body as possible, that way as soon as the throttle plate closes air is evacuated...but having said that if you are recirulating, its a bit more plumbing to get that to work right...but anywhere AFTER the intercooler is good...

[camaro]

Recirculating also helps keep the turbo spooled.

[RickDaTuner]

just adding on to the Info already posted..

a BOV that vents to air will not make a car stall completely but it will make it bog down, in some cases it does give weird Idle problems.
But the reason for the boging is that when you are on full throttle, you reach redline, and then shift, the BOV releases all the static air into the atmosphere wich result in the next second or two of the car engine jerking.
In normal operation a pypass valve will recirculate all the static air back into the intake track, this is done to allow minimal pressure drop and a allow the turbo to keep spooling with the use of it own compressed air.
So the reason you feel that bog is becaue the ECU has already mesured the air and has set the air/fuel mixture acordingly, so when you vent to air, you are throwing the ECU off and causing the car to run very rich so rich that the fuel has a hard time combusting in the cylinders.
A vent to amosphere BOV should reall only be used if you are running a stand alone ECU, or if you are running a heavy spring in the BOV that will allow some of the boost pressure to remain in the intake track; high horspower cars use vent to air valves because those cars are usally producing in excess of 20psi, and well, it takes a while for 20psi to vent, so there is still some static pressure in your intake durring your shift.

If you ever heard a BOV on a civic its very short, but if you also ever heard it on a car like a Supra you will notice that its takes a while for it to finish venting, this is of course going from full throttle to closed throttle and no shift.

Like EK 2.0 said you should place the BOV as close to the Trottle Body as posible, but not so close that it creats turbulance and resuces HP, this make it more responsive and helps to prevent Trottle plate damage on higher Boost aplications.


hope that makes things more clear for you:thumbsup:

happy boosting:clap:

[90awdwagovan.]

Originally posted by RickDaTuner

A vent to amosphere BOV should reall only be used if you are running a stand alone ECU, or if you are running a heavy spring in the BOV that will allow some of the boost pressure to remain in the intake track; high horspower cars use vent to air valves because those cars are usally producing in excess of 20psi, and well, it takes a while for 20psi to vent, so there is still some static pressure in your intake durring your shift.

If you ever heard a BOV on a civic its very short, but if you also ever heard it on a car like a Supra you will notice that its takes a while for it to finish venting, this is of course going from full throttle to closed throttle and no shift.

Like EK 2.0 said you should place the BOV as close to the Trottle Body as posible, but not so close that it creats turbulance and resuces HP, this make it more responsive and helps to prevent Trottle plate damage on higher Boost aplications.


you sound hung over....

but yea, the main reason why people install a BOV is for the sound.... most stock bypass valves or whatever you wana call em do a fine job at preventing compresser surge...

.... and really... you don't need standalone to properly run a vented bov, just a speed density setup.

[90awdwagovan.]

also... a recirculated BOV will reduce turbo lag(every gear but first)

heres a well made cluster fuck with a recirculated BOV on a SD equiped car.

http://bmcrace.com/DSC02877.jpg
http://bmcrace.com/DSC02876.jpg
http://bmcrace.com/DSC02878.jpg
http://bmcrace.com/DSC02879.jpg
http://bmcrace.com/DSC02880.jpg
http://bmcrace.com/DSC02881.jpg
http://bmcrace.com/DSC02883.jpg
http://bmcrace.com/DSC02884.jpg
http://bmcrace.com/DSC02885.jpg
http://bmcrace.com/DSC02886.jpg

[achtung]

Where is your BOV recirculating to? I want to recirculate mine as well, it is vented right now and I hate the lag.

[turbo minivan]

many stock BOVs, such as Bosch leak at higher boost levels, most around 15 to 17 or so. what you can do about this is, (depending on what BOV it is and if you know what the internals are designed like) you can flip it. instead of mounting it like it should be, you can flip it so the side that would normaly let the air out, is mounted in the boost line. that way, (again, depending on how yours is designed..) it can not leak at ANY boost level because now instead of your boost PSI pressing against the valve pushing it up, its pushing against the valves stem acctualy helping keep the BOV closed tighter at boost. i know this works for Bosch BOVs like off a turbo saab, but im not so sure about too many others.
you can try this if any of you are having a leak problem and youll
notice fast if yours will work like this or not. if it dosnt youll notice by a drop in max boost or a duck call sound or whistle when in mid to higher boost. thats what happens if you try flipping a stock
dodge BOV because of the design. try it out. ...... just in case any one was wondering or had that problem.

[RickDaTuner]

Originally posted by achtung
Where is your BOV recirculating to? I want to recirculate mine as well, it is vented right now and I hate the lag.

the intake after the air filter, before the Turbo, not on mine but that is where they get recirulated to :)

[RickDaTuner]

Originally posted by turbo minivan
many stock BOVs, such as Bosch leak at higher boost levels, most around 15 to 17 or so. what you can do about this is, (depending on what BOV it is and if you know what the internals are designed like) you can flip it. instead of mounting it like it should be, you can flip it so the side that would normaly let the air out, is mounted in the boost line. that way, (again, depending on how yours is designed..) it can not leak at ANY boost level because now instead of your boost PSI pressing against the valve pushing it up, its pushing against the valves stem acctualy helping keep the BOV closed tighter at boost. i know this works for Bosch BOVs like off a turbo saab, but im not so sure about too many others.
you can try this if any of you are having a leak problem and youll
notice fast if yours will work like this or not. if it dosnt youll notice by a drop in max boost or a duck call sound or whistle when in mid to higher boost. thats what happens if you try flipping a stock
dodge BOV because of the design. try it out. ...... just in case any one was wondering or had that problem.

cool first time ive heard that, another think that can be done when pushing higher boost levels that the stock BPV or BOV cant handle, is crush the top of the can, this will increase the spring rate by having it pre compressed and allowing it to hold more boost:thumbsup:

[EK 2.0]

Originally posted by RickDaTuner


cool first time ive heard that, another think that can be done when pushing higher boost levels that the stock BPV or BOV cant handle, is crush the top of the can, this will increase the spring rate by having it pre compressed and allowing it to hold more boost:thumbsup:


ohhhh so you STI guys are biting old DSM tricks are you now??...haha

[atomic]

Originally posted by RickDaTuner
[B]If you ever heard a BOV on a civic its very short, but if you also ever heard it on a car like a Supra you will notice that its takes a while for it to finish venting, this is of course going from full throttle to closed throttle and no shift.
lol

[RickDaTuner]

Originally posted by atomic
lol yeah yeah worst analogy ever.. civics arent turbos blah blah blah blah i was half asleep

[RickDaTuner]

Originally posted by EK 2.0



ohhhh so you STI guys are biting old DSM tricks are you now??...haha yeah but at the cost of some pretty damaging compressor surge:(

[turbo minivan]

Originally posted by RickDaTuner
yeah but at the cost of some pretty damaging compressor surge:(

wrong! no compressor surge AT ALL!! why would it? it in no way effects your vacuum assist in your BOV. it works just like it should
if not better and your not gona leak boost at all.
also if anyone here does want your gay plasic stock dodge BOV modified to take over 15 psi, you can streach the spring in it or add spacers under the spring. i would not recomend squishing your BOV though to stop it from leaking. a couple other things can be done that are alot less "hack joby" to get a higher resistance out of it.

[finboy]

a lot of turbo dodge guys mount the bov on the hot air pipe, and vent hot air instead of air that is already cooled, personally i'm mounting mine by my throttle body because i'm a lazy ass and the pipe is already made.

[turbo minivan]

yup, im a dodge guy and mines on my "hot pipe". acctualy, 2 are on my hot pipe.

[turbo minivan]

you can also flip a turbo volvo BOV. i got one from "pick-your-crap"
the other day and the design would take it perfectly!

[RickDaTuner]

Originally posted by turbo minivan


wrong! no compressor surge AT ALL!! why would it? it in no way effects your vacuum assist in your BOV. it works just like it should
if not better and your not gona leak boost at all.
also if anyone here does want your gay plasic stock dodge BOV modified to take over 15 psi, you can streach the spring in it or add spacers under the spring. i would not recomend squishing your BOV though to stop it from leaking. a couple other things can be done that are alot less "hack joby" to get a higher resistance out of it.

the Extra weight on the spring makes the Valve close earlier resulting in, un vented boost causing the Turbo to come to a screecing hault. this is on our Subarus though, crushing the can is only a Bandaid before you need to move on to a aftermarket BOV/BPV

[RickDaTuner]

for more Correct and Factual information click http://www.gofastbits.com.au/index.php?parentid=tech_info&option=tech_info there although everyone here has contributed some correct points, there are still some misconceptions, and also every car is built differntly

[turbo minivan]

Originally posted by RickDaTuner


the Extra weight on the spring makes the Valve close earlier resulting in, un vented boost causing the Turbo to come to a screecing hault. this is on our Subarus though, crushing the can is only a Bandaid before you need to move on to a aftermarket BOV/BPV

streaching the spring, or squashing the can is doing the EXACT same thing as getting somthing else that will hold more boost...
a tighter spring. so, like i say, flip it on its side and you wont have to touch the spring at all cause the boost will actualy help keep the valve closed. and also, "most" BOVs wont "close early"
considering that unless your under boost, the vacuum will keep your valve open untill boost closes it, thats why you sometimes see a BOV with a filter on it, cause under vacuum its actualy drawing air in cause its open. notice how your BOV dosnt just go... psst, it goes ppssssssssssss.... if it just opens and closes instantly, oh ya, youll notice a tss tss tss tss, THEN, you know your springs too tight. your spring would have to be REALY tight for it to close early, and if you think its doing that, its probly not even opening at all. moral of the story, if your gona stretch springs or crush cans, do it a little at a time, or, better yet, get an adjustable BOV.

[tristanlee85]

Originally posted by turbo minivan
yup, im a dodge guy and mines on my "hot pipe". acctualy, 2 are on my hot pipe.


Originally posted by turbo minivan
you can also flip a turbo volvo BOV. i got one from "pick-your-crap" the other day and the design would take it perfectly!

I was searching google for my Pierburg BOV and it directed me to this thread. I got m BOV from a Volvo today from the "pick-your-crap." From what you were saying above, does that mean the Volvo BOV will fit on a DSM flange? Sorry if I totally screwed that up, but I'm looking for a flange and I have access to buy the DSM flange, but not the Volvo one.

[turbo minivan]

as far as i can think the flanges are the same shape but it probly wouldnt line up. when you do install it though, try it like i say and flip it the oposite way it should be, and you should see NO boost leak at all with no side affects. the volvo BOVs are sweet eh?
too bad some idiot crushed the can on the one i got from the junk yard!!.... but for 5$ how can you go wrong?