This is the big BOV thread. If you didn't find this thread, you didn't search.
This thread is where all BOV question threads get merged into.
The quote below in this first post is from our BOV info sticky and contains links to some very explanatory BOV information. Please take the time to explore the links before you ask repeated questions.
A stock WRX/STi comes with a BPV (Bypass valve) which is a vacuum-actuated valve designed to release pressure in the intake system when the throttle is lifted or closed. This air pressure is re-circulated back into the non-pressurized end of the intake before the turbo.
An after market blowoff valve (VTA) does basically the same thing BUT unlike the stock unit it releases air to the atmosphere (giving you the loud sound). Some people see an after market BOV on a stock WRX as being in poor taste (probably due to the fact that it is basically a noise maker that really as no other benefit), while others simply find the sound very attractive.
Proponent opinions notwithstanding, there is a small mechanical downside to having an after market BOV (VTA) on a stock WRX. The problem comes when releasing air to the atmosphere that has already been metered by the mass airflow sensor. When the BOV releases (blows off), the ECU will be injecting the wrong amount of fuel into the cylinders. The engine temporarily runs too rich (meaning too much fuel is injected into the cylinders). This temporary rich condition isn’t typically THAT harmful, but it may cause bucking or hesitation on lift-throttle as well as some other concerns outlined in the links below.
It is BAD, period. Please do not try to confuse people with theories. It is a proven fact that a BOV on a WRX causes a rich condition which is bad and the only reason people buy them is for the sound.
BOV = CRAP for non to slightly to even somewhat modded subies!
If you wanna argue with people with a lot of time behind the wheel of subies, fine! I'm going to start hosting clubBOV.net soon. You can just go there, get flamed, look at riced out cars and go to bed.
How many BOV threads will it take?
YES, YOU WILL RUN RICH! IF YOU LOVE FOULED PLUGS, BY ALL MEANS, BOLT ONE ON! GO PSSSSHHT PSSSSHT TILL YOU MOMS TELLS YOU TO BE QUIET IN THE DRIVEWAY, BUT KNOW THAT IT IS BAD FOR YOUR CAR!!!!!!!!!!!
go ahead, ask again what kind you should use. sure, KHS is great...
BTW, how much RAW JDM power are you looking to gain from something dumping your oxidizer outside your INTERNAL COMBUSTION ENGINE?
I have done many searches on this btw, and blah blah etc. Can someone help me?
1. Took off my stock BOV
2. Took black.. vacuum/piping off.. (I guess you can call it that, pretty fat.)
3. Took small black line off.
4. Now when I put my new BOV on, how do I put the fat black vacuum? Do I plug it with the black piece they gave me and just stick the new BOV right on, put in the small line and leave it all that?
I have done many searches on this btw, and blah blah etc. Can someone help me?
1. Took off my stock BOV
2. Took black.. vacuum/piping off.. (I guess you can call it that, pretty fat.)
3. Took small black line off.
4. Now when I put my new BOV on, how do I put the fat black vacuum? Do I plug it with the black piece they gave me and just stick the new BOV right on, put in the small line and leave it all that?
Remember..it is now a BOV..so it blows to atmosphere. The "fat" line is the stock recirc line. It sends the air that has already been measured by your MAF back to where it should be (hint, hint:thumbup: ). The BOV will "blow it off" to atmosphere via this same line, which will no longer be connected. Just put the BOV on, connect the small black sensing line, and your in business. Don't blame me though if your car starts stuttering and hesitating and backfiring a little bit.:thumbup:
I have done many searches on this btw, and blah blah etc. Can someone help me?
1. Took off my stock BOV
2. Took black.. vacuum/piping off.. (I guess you can call it that, pretty fat.)
3. Took small black line off.
4. Now when I put my new BOV on, how do I put the fat black vacuum? Do I plug it with the black piece they gave me and just stick the new BOV right on, put in the small line and leave it all that?
I have done many searches on this btw, and blah blah etc. Can someone help me?
1. Took off my stock BOV
2. Took black.. vacuum/piping off.. (I guess you can call it that, pretty fat.)
3. Took small black line off.
4. Now when I put my new BOV on, how do I put the fat black vacuum? Do I plug it with the black piece they gave me and just stick the new BOV right on, put in the small line and leave it all that?
Also, the stock black small tube doesnt fit the BOV, so I pulled it off of the old BOV and off of where it was connected at start, now I can't get the smaller one the BOV came with on where the stock black line was cuz its to small? Hard to get in there anyways.. So any help?
Try posting this in the regional forum, a local guy to you might be able to lend a helping hand.
Please read all the stickies we have about BOVs, good luck.
Yea, get rid of the bov.. It messes the engine up.. You need to read more of the forums around here... I have learned a lot here, but I guess you haven't.. I don't have my sti yet but very soon!
But if you really want to keep that bov, just remember it gives you another 200hp and you get to hear that pssshhtt! :rotfl: :rotfl:
ROLF ROLF.. Uh yea, I'm pretty sure were not back in second grade. My STi is far from stock (Thank god they did it before I bought it). Anyways it is not recommend for STOCK.. I've read around here, I'm pretty sure you haven't *Sound familiar?*. Anyways thanks for the advice, I got it in, runs great!
I was under the impression that a stock WRX has a compressor by-pass valve in leu of the bov.
Another option if you have to have one is getting a recirculating bov. That way some of the air goes out and Pssshht, and some air goes back into the intake.
I agree with everyone that is saying No to BOV's. I was in this same position. I wanted a BOV so bad that i would do anything for that PSH noise, but then i did research and found out that it is bad for your a/f ratio. So what i did was bought a Short Ram SPT intake which gives it a little psh although i know intakes aren't the greatest for your car, but they dont harm it. after i got the intake, i wasnt happy with how loud that psh was, i mean, i was able to hear it, and people outside were able to hear it, but then i heard there was an intake silencer, so i took that out too. After i took out my intake silencer, it sounded a little better and not only did i get that psh noise i wanted, but i also took some 7lbs of weight out of my car by removing that intake silencer. If you want the psh noise that bad, and you want the bov. i mean, it is your car, do what you want, but what i recommend is an intake and a silencer removal. Not saying that intake is good for your car, but it is the best choice for a psh noise.
there you go
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
Subaru WRX Forum
3.2M posts
152.7K members
Since 2001
We invite you to join our Subaru Impreza WRX and STi community to discuss engine mods, builds, detailing, and more.