BOV recirculation question...

[dsylvia]

ok, i have to recirculate my greddy BOV and I've heard that you have to recirculate it between the turbo and the MAF on the intake pipe. however, my greddy intercooler kit, on the pipe to the right of the intercooler, has a small tube welded on it......

my question it, can i just recirculate the BOV into that tube. cuz then i wouldnt have to worry about making an intake pipe with a port on it and i would be able to hide the recirculation tube better.

also, if this would not work, could you please explain to me why. I dont totally understand why you have to recirculate it in the first place. all i know it that if i dont, i will most likely stall out.

thanks in advance for any help -derek-

[Import_Ant]

there should be two tubes on your intake, one for the PCV hose coming from your valve cover and other for BOV recirculation. if you only have one then I assume that is intended for the PCV hose. you can use any bung on your intake as long as the hose seals around it, if you don't attach your PCV hose you can add a small filter on the end of the PCV nipple on your valve cover or route it to a catch can (<-better of the two Imho)

the reason you need to recirculate your bov on a MAF based car is that the ECU adjusts your fuel trim based upon the air it meters coming past the MAF. so if you have a boost leak, or atmostpherically vented bov, the car will run PIG RICH when the air is escaping because the ECU has accounted for that air and assumed it made it past the throttle into the engine (which it didnt because it escaped) so the computer has added fuel to team up with the air to make *DA DUM* ideal AFR team, but the air doesn't make it there so the fuel is all alone and says "fine screw it I'll just try to burn by myself" which causes the engine to be overly rich, stumble, and sometimes die.

hope my goofy analogy helped but that is my input on your BOV ricirculation question. I am NOT recirculating my BOV, I just have to tap the throttle a few times if I go from heavy acceleration straight into neutral. You can run without recirculating, you just have to adjust your driving style. leave it in gear when you decelerate, keep an eye on the throttle if you get up past 2k rpm and just 'let off the gas' abruptly.

not sure what BOV you have but most have an adjustment to make it 'stiffer' (each car operates at different levels of vacuum at idle. to keep the BOV from leaking in a car that operates at a large amount of vacuum the bov needs to be stiffened up. take advantage of this setting if your bov has it to stiffen it as much as you can. it will make it less likely to open under minimal pressure and improve your city driveability as a result)

happy boosting-Aaron

[dsylvia]

thanks for the info man. that def. cleared things up.

but.....haha....if the point of recirculating is so the air does make it to the throttle, which i understand, why would it matter if i recirculatethe air into the intake pipe or back into the intercooler piping after the turbo, but before the intercooler? know what i mean. to me it seems like the same thing is being accomplished, but i could be wrong.

[dsylvia]

to better illistrate...here is a picture.

i'd like to recirculate the BOV in the port the red arrow is pointing at.

[Craving4Boost]

hmm interesting...that could very most likley be your recirculating port...it doesnt seem to be a BOV flange to me or for the IACV hose or anything.

[Craving4Boost]

actually i take that back i'm not sure anymore haha...that doesnt look like a good place to recirculate

[dsylvia]

haha, why do you say it doesnt look like a good place?

[jmwenick]

It looks like it will work to me, also, why would they put that there if it was not intended to recirculate there?

[cyrus240sx]

but that point on the IC piping is still pressurized by the turbo so i think that wouldnt work for recirculating purposes, it has to be after maf, before turbo to work IIRC

[rn240sx]

I dont think that would be a good idea.....

If u had it hooked up that way, that means u would have pressure on both sides of that valve..!!!

Think about it.... When ur under boost, u will have pressurized air at the base of the bov cause its mounted to the IC pipe.... You then have your recir hose routed to another IC pipe which ALSO has pressurized air flowing thru it so HENSE..... you will have pressurized air BACK FEEDING thru that recir hose...!!!

Basically u will have pressurized air under the bov (which is normal) AND comming in thru the outlet ... which is NOT normal... because you have that recir hose hooked up to an intercooler pipe...

Now u will have pressurized air on both sides of that valve... One side would be pushing to open the bov and the other side will be pushing to keep it FROM opening...

I may be TOTALLY wrong here... But thats my theory..

I think thats a bad idea... Thats why we recir b4 the turbo inlet... Cause there is no pressurized air there...

I have an AFC... so that i dont have to worry about that recir crap.....

[Import_Ant]

I dont think that would be a good idea.....

If u had it hooked up that way, that means u would have pressure on both sides of that valve..!!!

agreed X infinity.

you HAVE to recirculate your BOV PRIOR to the turbo.

think of it this way... if you recirculate back IN to the IC piping.... what is the point of the BOV in the first place? (this is assuming the valve would even open) the BOV's purpose is to release the pressure between the turbo and throttle body. if you vent FROM the ic piping back INTO the ic piping there is no pressure loss.

if you vent from the IC piping into an environment where there is no pressure, you have pressure loss. you have to release that air back into the system after the maf but before the turbo.

hope that all made sense.

[dsylvia]

haha, thanks guys. its clearer now. now i feel like a dumb ***, lol.

thanks for the help.-derek-

[SonyPete]

Yea if anything the outside of the BOV is gonna be more pressurized then the inside. Since the Outside has pressure comin right before the intercooler, so the pressure on the outside is gonna be stronger and even push air into the BOV if it were to open.

[Silverbullet91]

I think that pipe on the turbo piping is for the stock bov to connect to. Since you are using an aftermarket bov (I assume) this pipe is going to have to be plugged/welded up. You can't recirculate the bov to this hole. You will have to recirculate it to in between the mafs and turbo.

[eddiec]

I have an AFC... so that i dont have to worry about that recir crap.....

and how does this work? are you still using a MAF?

[DRIFTEADOR]

it locks maf voltage to the ecu so it doesn't add more fuel after you let off the gas