Vent BOV to atmosphere?
 

I was wondering how every one is venting their BOV to atmosphere with using the stock r33 version 2 maf? I have an rb25 swap in my s14 and im looking into figuring it out. I know about half of dsm guys do it with out any problems but the other half have stumbling when off throttle and bad fuel economy. Any help would be appreciated.

Eric

For starters, you need an aftermarket BOV. The stock ones are recirc valves and do not work venting to atmosphere. One install, simply plug the hole on the intake pipe and your done. It will create a momentary rich situation when they go off which if you are rilling to a stop or reving down the engine can sometimes cause a stall or stumble just as with any other air flow meter car. Recirc is always better for MAFS cars. Another option is a 50/50 valve like Forge and some other companies sell that recircs half the flow to keep it running better but still gets the sound.

With my old skyline, I used the stock valves recirc the entire time since they worked so well. They were also quite loud for recirc valves. That was however an rb26.