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.
dont screw with boost until you get the proper gauges, (boost + egt. Have fun installing that upipe should u choose to buy one...
Hippy's links should be very helpful.. But dont be sucked into the idea that u must have an intake and BOV. Neither really benefit performance unless you are running a huge turbo, and have spent over 2g's in that related area. some, if not most actually hurt performance.
also get used to the idea that 7 out of 10 dealers are very trigger happy when it comes to voiding warranty due to modifications.
we have laws that protect us, but subaru can still screw us...
word of wisdom... wait till 1k miles before letting her rip, and be gentle on that transmission... last but not least, smile you have yourself a great car, that excels in just about every test that is thrown at it.
Easy mod to do that will help people learn how to take the intercooler off and put it back on. It also makes this process easier cause the hoses are more pliable. Could be a good stepping stone........
Easy mod to do that will help people learn how to take the intercooler off and put it back on. It also makes this process easier cause the hoses are more pliable. Could be a good stepping stone........
I was just assuming he wanted some quick mods to do to the car, and while I would agree that an up-pipe is a more effective mod, it's also an extremely difficult thing to install compared to an intake, bov, mbc etc...
If you feel comfortable installing an up-pipe or can pay to have it installed, then I would change my recco to an up-pipe over samcos....
bov is not a performance mod. I always wonder why people put it in a list of mods, when they ask which car would win given these mods...
Plus, a bov may screw with your car...leaking under certain condition.
But to answer your questions, and what others have suggested...uppipe is one of the cheapest mod. However, it's one of the toughest mod to perform.
Just something to consider. Replacing any cat or deleting any cat is against the law. And if you have to comply with emisions regulation around your area, then you may need to think about that.
Yeh, I didn't mean to assume that anyone was a new-b or anything(not that it would be a bad thing).... I just think if ya pay $150 for something, there is no reason to pay that much to get it installed(which is the least amount you'd pay to get an uppipe installed if you don't know someone). If you are a new-b and reading this, installing an uppipe probably sounds pretty hard, especially since most downpipes don't even know what they are when you ask them if they can install them. That with the thought of killing the car and then having to have someone else fix it could be pretty scary. This would be why I say to save your money and do some reading.
Installing something on your car is a lot easier, less expensive and more rewarding in many ways then having someone else install it(especially if they screw up and you payed all that money for a poor install). This is kinda why I put all the links up there.... When you get your car(if you don't have it yet), you might wanna go out and get stuff as soon as you can, but that might not be the best idea in the world(for many reasons). Not that everyone has or want to take the time to know what they're actually doing to the car when they upgrade it, or that they wanna do the installs themselves, but I thought you might .
I was just assuming he wanted some quick mods to do to the car, and while I would agree that an up-pipe is a more effective mod, it's also an extremely difficult thing to install compared to an intake, bov, mbc etc...
If you feel comfortable installing an up-pipe or can pay to have it installed, then I would change my recco to an up-pipe over samcos....
exactly... an upipe is a great mod, i just dont know anyone who regularly works on subaru's and does alot of up-pipe swaps. Ive done my reading, and if someone would direct me where to go to have it done, otherwise it wont be done. I dont have the tools, the lift, the garage, etc. I wont trust anybody who hasnt worked on a wrx, specifically the uppipe.
NO ONE in dayton works on subaru's. Maybe i could convince my subaru dealer to do it. Afterall It would be a mod that is preventing them from doing a turbocharger swap. I dont trust catalytic converters one bit, i had one break apart in my dodge.
Ive done my reading, and if someone would direct me where to go to have it done, otherwise it wont be done. I dont have the tools, the lift, the garage, etc. I wont trust anybody who hasnt worked on a wrx, specifically the uppipe.
This is why other mods like turbo timers and intercooler hoses are good places to start. They build confidence in workin on the car for people who are weary. Also, with the money you save from the labor on the uppipe, you can start your tool collection. I am no expert with any type of car, but I've learned a lot more about cars(expecially subarus), from working on my car. Anyways, you can get a jack, some car stands, and all the tools needed to do an uppipe install for less then anyone(but family or friend) would charge for the install. This and the fact that noone knew what it was around me, drove me to do the job myself(I'd definately do it again). I also know a few wrx tuners that got started installing peoples uppipes in parkinglots(so you really don't need a garage).......
I have to agree with hippy78 again - I started out by doing the I/C hoses, then did some gauges, intake, other hoses, engine mounts, leather seats, intercooler spray system and a Stoptech Stage 2 brake kit. I had never even touched a car before and all I had was a screwdriver to my name!!
I started w/Turbo Timer, MBC, and Hoses myself... Helped me to learn about the Subaru. As time went on, I tackled more and more difficult installs like the turbo-back, UTEC and up-pipe. Then I did Turbo/Injectors/Fuel Pump. Finally I took the plunge and installed my FMIC myself!
Working on the WRX is not hard, it's an easy car to mod, but start small and begin to learn it before you do something big like the up-pipe.
While I claim that I am a pretty fair mechanic, I did not install my up pipe myself (you cant even see the thing from the engine bay, let alone remove it).
Why not have some one remove your stock up pipe for you and then you can gut it (do a search on gutting). You will get over 10 whp from this mod.
With a little luck you could find a qualified individual who would do the labor for under $300.
A great many of us think that a catless up pipe (be it aftermarket or stock/gutted) is one of the best single mods for the Rex.
I talked to JC motorsports in columbus, and one of the workers would do the install, if i bought the helix flex uppipe thru them. It's marked up to 200, but theyd be willing to do the install for no additional cost, just as long as i help out.
does that sound pretty good? I know the helix has a flex joint that could fail. But my egt's should be low because ill be stock turbo on cobb software. 8 years it should last, or so they said over the phone. But i hear the are pretty leak-free.
So not only would the install be reasonably priced, but It'd be a learning experience for me.
SO , looks like ill be doing an uppipe soon
anyone know how to avoid throwing a code for the uppipe?
I would go with ECU upgrade that is what i started with and I'm sixteen. And now I have s/r 50 turbo and FMI and 3.5 exhaust and fuel upgrades. And all begins with ECU (UTEC, APS, COBB, Vinushu,AEM, APEX'i, Greddy)
rachet, extensions, 10, 12, and 14mm sockets, and adjustable wrench. Plus Jack + stands. For what you would pay someone for the install, buy some good tools. Same money spent, then you have the tools to do future work. Tools are a GREAT investment.
Now, a wider assortment of tools (especially getting rid of the adjustable wrench!) will help a lot, but aren't completely necessary.
FWIW, I in no way consider myself anything close to a mechanic, and I did the up/down pipe install without a hitch. Lots of steps, but nothing hard to do.
I did up/down/boost (w/guages) first. I'm happy.
VV
MidnightFLAT4 said:
I talked to JC motorsports in columbus, and one of the workers would do the install, if i bought the helix flex uppipe thru them. It's marked up to 200, but theyd be willing to do the install for no additional cost, just as long as i help out.
does that sound pretty good? I know the helix has a flex joint that could fail. But my egt's should be low because ill be stock turbo on cobb software. 8 years it should last, or so they said over the phone. But i hear the are pretty leak-free.
So not only would the install be reasonably priced, but It'd be a learning experience for me.
SO , looks like ill be doing an uppipe soon
anyone know how to avoid throwing a code for the uppipe?
For 300 find a used uppipe and a downpipe. Thats the most power your going to get for $300. And dont do the resistor fix, do the sparkplug antifouler fix/ 100% mechanical and can be restored to stock in a couple of mins, somthing you cant do with a reistor.
For 300 find a used uppipe and a downpipe. Thats the most power your going to get for $300. And dont do the resistor fix, do the sparkplug antifouler fix/ 100% mechanical and can be restored to stock in a couple of mins, somthing you cant do with a reistor.
Anybody else surprised by this? I mean - with the STi putting out ~73hp more at the crank than a regular WRX, you'd think the STi turboback would be better in some way?
If it's the same diameter, is there something else different about it?
-Vin
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