Just curious if anyone is venting there blow off valve to atmosphere with a mass air flow driven engine management system? I know with dsms if you try it will run like complete ----. Just curious if the car runs ok and doesnt throw a CEL like that. I would assume the car would get some type of mass air flow code or system rich code.



thanks

 

It's weird how every maf system is different because my buddy with an STI vents his without any probs unless Subies don't use maf sensors.

 

i thought there BOV's where different thou
Like they had two vaccuum sources or two of something

 

 

As long as the spring is tight enough to stay shut at idle (stock DSM's are not) it can work. But you will run rich while venting because the MAF thinks that air is going into the manifold when it's really not.
Unless the MAF is set up as a blow through, then it does'nt matter.

 

1.8t's do ok but if you look at the value blocks in VAG-COM you can see the jump in A/F

 

If the BOV is open while in vacuum, the are is going into your engine thats not being measured by the MAF so youll run lean.

 

Was just talking to my roommate about this today. He runs un-recirc'd on his subaru... but it isn't tuned of a MAF. It uses the Utec to tune off other settings, so the circ/recirc doesn't change anything.

 

hmm this is what I was afraid of, the dsm bov is definatly not strong enough to stay shut at idle so I think its definatly going to throw a code. Greatttttttttttttttttttttt, just more ------- plumbing I have to do

I'm done turboing cars

 

I ran the BOV venting to the atmosphere on my probe, I just set the MAF sensor up so that it was right before the throttle body and after the BOV. It worked great set up as a blow through design when I used an safc with it .

BTW: I knew a guy who ran it as a draw through design like factory but then he changed it to a blow through setup and said that it felt alot better and thought it had alot more power, also I never got a CEL with that setup .