Hey guys, I have a bov I want to install on my 87 FC Turbo. The problem is I dont know where it is supposed to go. Someone told me they think it replaces the EGR valve, is this true?
Please help, and if you have pictures of where it goes that would really help alot more. I do have have alot to learn, Thanks. Any advice is greatly appreciated.

 

oh boy you have been seriously misinformed, I don't have any pictures to show but i think you should do some research before doing this mod.

if your car is stock with an Air Flow Meter (AFM) then you must recirculate the BOV back into the intake system so the reading the AFM has sent the ECU remains correct.

 

Look on the left of the engine bay.


closer in


Even closer


Can't get much closer than this


Hope this helps!

 

The BOV installs to the intercooler piping somewhere between the turbo outlet and throttle body. Closest to the throttle body is ideal but in the real world, they are generally installed wherever they can be fitted.

Your stock bypass valve (a BOV that recirculates back into the intake after the AFM) is on the turbo outlet pipe, just after the compressor. You can follow the hose from it back into the TID.

You would replace that stock bypass valve and plug the now unneeded hole in the TID.

However since there are few "kits" to install an aftermarket BOV onto the FC, how it gets mounted is up to you. Most certainly, the stock turbo outlet pipe will need to be modified or a new one fabbed up.

But it's a pointless thing to install on a stock turbo setup. It just makes a "Pssssshhhhh" noise and causes excess fuel to be dumped into the exhaust.

 

if you want the pshhhhhh ricer sound, you can first try just removing the re-circulation tube on the stock bypass valve. it will hurt your fuel economy and probably horsepower too though.

 

But if you do that you'll need to add a check valve as the recirc valve leaks a bit at idle.

 

Aaron is right, you will need a check valve. Anytime there is vacuum in the manifold it's open. You'd be lucky to get the car to idle.

 

And just to add, I've run a BOV on a stock turbo setup before. While the sound is "exciting" for some, the backfiring and decreased cat life isn't worth it. And to be honest, stock boost levels ~5psi aren't going to make much of an audible whoosh noise...

 

backfiring? and decreased cat life. Who cares dude you drive a sports car. The car will backfire either way when you go aftermarket exhaust. but then i suppose you wouldn't worry about cats unless you need to pass emissions :/

 

not entirely true. you done have to recirculate it. but it is a good idea.

OP: what mods do you have done? that will help us a lot to tell you where to locate it. if its stock IC or do you have a FMIC?

 

My S5 has full 3" exhaust... no backfiring... If your car is backfiring after adding exhaust, you most likely have fuel control issues (on a turbo car).

The cats I mentioned because some of our members (myself included) need to pass emissions. And I actually appreciate the sound control cats offer as well (personal preference).

Just trying to give the OP all the information he might need to consider.

 

Well my N/a backfires and there is nothing wrong with it. I've seen plenty of turbo'd ones do it to. It's the way the engine is designed. Backfiring does not mean there is something wrong.

 

Actually I dont think backfiring will be a problem as I have a complete racing beat exaust package installed....no cats, just a silencer and mufflers. That is the only thing I believe is aftermarket on the car relating to performance.
Also, Im thinking about getting the car registered as a classic so I no longer have to get it inspected anymore.

 

Thank you for the pictures, It does help to know where its supposed to go!

 

Aaron could you give me any Ideas about what type of connection design I would use to install it on the outlet pipe? Thanks.

 

You get a pipe ~2" in diameter that goes between the turbo and the elbow connecting to the intercooler. you weld the flange onto it that corresponds to the flange on the bov.




BOV's are a pointless, additional failure point. I run the stock afm with no bov and no problems. When throttle blades close, all that air goes back out the afm, just like it does with the stock re-circ valve.

 

From some modified FMIC set-ups that I have seen... It looks as though some people do not even use BOV's. Isn't a BOV necessary for cars running above stock boost?

 

Research into it, lots of debate. My take on it is that^

 

Common parts that are not necessary for an engine: Blow-off valve, pop-off valve, compressor bypass valve, wastegate, turbocharger, intercooler, and air filter. Whether or not you want to use any of these is up to you and your local law.

 

While not necessary, a bov/recirculation valve serves to prolong the life of the stock turbo. They don't take kindly to compressor surge and will begin leaking oil in pretty short order especially above stock boost levels.

 

The only reason to run a BOV is if you want to plumb it back to shut it up a bit. I ran no BOV on a t04z at 18psi was loud, makes you look like a ricer. The compressor surge thing is a big debate

 

It's a straight piece of pipe with a flange welded to it to match your BOV.