Vent BOV to atmosphere w/ MAF driven ems
 

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

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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

Re: Vent BOV to atmosphere w/ MAF driven ems
 

http://www.wrx.ch/images/fx.jpg
http://www.wrx.ch/images/pop.jpg

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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

Re: Vent BOV to atmosphere w/ MAF driven ems
 

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 ;D.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

You can crush the dsm blow off valve to keep it closed at idle.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

my employee has a 95 eagle talon, 20psi daily and vents with no problems.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Good now sell me Homemadeturbo.com for $5.00 ;)

Re: Vent BOV to atmosphere w/ MAF driven ems
 

either blow-thru the mafs, or recirculate.

I was running an atmospheric on mine, one day decided to recirc it. Car ran 1000x better

Re: Vent BOV to atmosphere w/ MAF driven ems
 

I have a crushed one, yes is stay's shut, and I can vent, but if the boost is higher then ~16ish the pipes blow off while I let off because it's too hard to open.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

hmm you must of crushed it too much.I crushed the one in my talon and I had the boost set at 18 never had any problems.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Venting on a MAF car just isnt a great idea (unless its blow-through). I wouldnt even consider non-recurculating.

MAF is like ooh, air..yum better add some fuel. Air gets vented, fuel gets injected anyways. it's a mess

Re: Vent BOV to atmosphere w/ MAF driven ems
 

People only install VTA bov's on MAF systems for the sound, and very rarely have turbo life or throttle response or even quality of idle in mind when they do so, which is stupid. To them having a loud BOV is worth it I guess

I love stock WRX's with nothing but BOV's on them. ::)

Re: Vent BOV to atmosphere w/ MAF driven ems
 

well its definatly throwing a low input maf code, but the valve is not even open at idle... odd, I'm still gonna plumb it back into the intake pipe.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Can you run the MAF in blow thru mode?
The setup on my mustang has the bovs right before the IC inlets. The MAF is after the IC and before the throttlebody so all the air it meters goes into the motor.
Erich

Re: Vent BOV to atmosphere w/ MAF driven ems
 

I'm venting to atmosphere on the WRX with a turbo xs blow off valve, the type that the whole shaft moves up and down and opens some wholes on the side, because it stays shut until I shift I have no problems. It does backfires sometimes under hard acceleration when I shift.

I tried using the factory subaru bov, venting to atmosphere and it ran like crap. The greddy type-s can be adjusted to stay shut so it works too.
The one on the picture postd up seems to work good, it does both things.

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Where is a Bullshit Flag when you need one :P

Re: Vent BOV to atmosphere w/ MAF driven ems
 

I did this on my old MX6 GT... car accelerated so much better, and boost came in way sooner, only issue was drivability and backfiring ::) ... it sounded cool for the 30 minutes I left it like that...

Switch to MAP, it'll be happier...

Re: Vent BOV to atmosphere w/ MAF driven ems
 

What about mounting the BOV before the MAF meter?

Stan

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Even with the valve fully closed at idle I'm still get a low input maf code, so recirculating the valve isnt going to do ---- :-\

Blowing through the maf isnt a option

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Jeff just wondering what you ended up doing eventually about the BOV? I have a '90 Saab 9000T and am going through the same ----

Re: Vent BOV to atmosphere w/ MAF driven ems
 

Bump