Recirculating BOV

[Kooldino]

I know that there has been a lot of debate over recirculating the BOV behind the MAFS to aviod the stalling of the car. I thought it would make s significant difference, so I went ahead and had it done. Cost me less than $10 worth of hardware from Home Depot (a couple of hose clamps, some hose, and a small pipe). Hopefully all Spool kits in the future come this way.

Yup, you guessed it..the car no longer stalls. Or even comes close. It doesn't dip below 900rpm ever. So BEAVIS: Yes, go ahead and get your 9lb flywheel if you wish.

I had the guy who did my exhaust today (which, BTW if you live within a few hours of Trenton, NJ, and want to boost your car, this guy is THE man...and is looking for Proteges to boost) do the work to recirculate the BOV, and I had him cut about 1" of pipe out of the center of my Spool intake (compressor->MAFS) so it could fit better, and when he cut it, I had him "straighten" the pipe so that it only bends in 2D, and doesn't "twist" on a 3rd axis (Spool owners will know what I mean). You'll be able to see what was done in the attached pic. Note that I have temporarily relocated the coolant resivoir.

My ONLY problem since I did this is the following...
I took the washer I had in the BOV out (was using it to tense the spring more), but since I did, I hear the BOV venting air at 10Hg. That's way too early. Now theoretically that shouldn't matter since it's recirculated, and drivability wise, I don't notice a difference. HOWEVER, my problem is that when I punch the throttle and start boosting, it JUMPS to 3psi and then SLOWLY climbs to 5psi. I'm not at 5psi until 5,000RPM, whereas I used to be at 5psi at around 3,000rpm (which is about where I build 3psi now). So I tried putting the washer I had back in to tighten up the BOV...but then it started it's stalling act again. So I'm thinking either I should find a very thin washer, OR maybe the BOV is not getting a very accurate vaccum signal. Any ideas?

 

[LinuxRacr]

Looks like the issue is with your BOV. Not sure yet what it is yet though.

 

[Kooldino]

Amen to that.

 

[blynzoo]

I always wondered about recirc. tube position. I know everyone places it behind the MAF, what would happen if it went in front of the MAF? (i.e. the opposite of what you have in the picture).

With the BOV issue, one would think that having the BOV venting early would actually lead to stalling. One thing to check is your psi right before you stall. does it jump?

 

[LaZaBLuEMp3]

do u still hear the bovc like u did b4?im guessing no and besides, other people fixed the problem without doing this so why does rec the bov stop the stalling?

 

[LinuxRacr]

I always wondered about recirc. tube position. I know everyone places it behind the MAF, what would happen if it went in front of the MAF? (i.e. the opposite of what you have in the picture).

With the BOV issue, one would think that having the BOV venting early would actually lead to stalling. One thing to check is your psi right before you stall. does it jump?

You don't want it in front of the MAF. Reason bein is that if you did this, it would be just like venting to the atmosphere. Remember, that the purpose of the recirulating action is so that the air already metered does not get discarded out of the calculation that the ECU has made on how much fuel to add based on what the MAF sensor already read. The air must return to the system because it was already measured by the MAF.

 

[Kooldino]

I always wondered about recirc. tube position. I know everyone places it behind the MAF, what would happen if it went in front of the MAF? (i.e. the opposite of what you have in the picture).

Then it would count the air all over again and you'd have the same issue as venting to atmosphere.

With the BOV issue, one would think that having the BOV venting early would actually lead to stalling.

It would if it didn't recirculate.

One thing to check is your psi right before you stall. does it jump?

I'll try messing with putting different washers in there and checking it.

 

[Kooldino]

do u still hear the bovc like u did b4?

I still hear it, but it's quieter now.

im guessing no and besides, other people fixed the problem without doing this so why does rec the bov stop the stalling?

The BOV stops the car from stalling because...

In a MAFS equipped car, the job of the MAFS is to tell the ECU how much air is coming into the car, so the ECU knows how much gas to inject into the cylinders. The problem is that if your BOV vents some of the already measured air to atmosphere, the MAFS & ECU don't know about it, so it gives it the fuel that it would have anyway, had that vented air actually made it to the intake manifold. The end result is a condition so rich that the engine bogs, and causes the car to stall.

 

[Kooldino]

Linux, could you post pics of your BOV?

 

[LinuxRacr]

Linux, could you post pics of your BOV?

 

[Kooldino]

Got a pic of it when it was hooked up?

 

[LinuxRacr]

Nope. Just look at the pictures, and imagine it upside down hanging under the intake pipe.

 

[Kooldino]

Any BEGI owners out there w/ a digital camera?

 

[Little Beavis]

So no stalling issues due to the flywheel, but you're still aren't "perfect yet".

Looks good, great work. So somehow you managed to do this without messing up the coating too much. Looks real good in the picture.

 

[Kooldino]

Yup, not perfect yet. But I'll keep you guys posted.

AFAIK, the flywheel is good to go.

 

[afrey2002]

Any BEGI owners out there w/ a digital camera?

It's nice and big so you can see it, it's right next to the AFPR (UFO)

 

[Kooldino]

OIC...