Thread: BOV Question *searched* NEED HELP!

There are two ways you can run atmospheric. You either program the AFC to minimize the effects of blowing off metered air when you exit boost, or you convert the system to blow thru, which can be quite a bit more complicated depending on your setup. Running blow thru means you have the MAF in the intercooler piping on the cold side, close to the throttle body. The reason why it becomes complicated is because the BOV needs to be between the compressor housing (preferrably between the intercooler and the throttle body, though some place it before the intercooler to blow off hot air). The other complication is that you need as few bends as possible between the TB and the intercooler, for MAF placement. The MAF needs to be at least 6" (IIRC) from the TB, etc. etc.

Just do some research on here with regard to draw thru vs. blow thru, and you'll find your answers to your recirculated vs. non-recirculated setups.

Yeah, I read a thread earlier today about draw though, vs blow through.

I do have an SAFC, is that what you mean by tuning teh AFC? Also, do you think the BOV may just need some more adjusting to run atmospheric? Again, I don't really need to run open...and really I don't care about it...I guess I'm more just curious as to why it was stalling. Also, I like to gather as much info as I can.

But other than that, you (all of you) have been an amazing help. And because of your help, my car is running better, and I'm really happy.

Well it's likely that your BOV is open at idle and while cruising, causing that metered air that was registered to be expelled, and you're stalling because it's dumping fuel and running rich. If you re-adjust the BOV so that it's shut at idle and cruising, you shouldn't have any stalling issues. IIRC, the AFC's have a setting that prevents the rich condition between shifts, and when you fall out of boost and expell the charged air from the BOV. That's what most of the RWD SR owners do, is just tweak the AFC settings and their cars run fine.

Right, that makes sense. It's measuring a bunch of air at idle, but by the time it gets to the motor, there isn't as much. That's makes sense, too, that it would not stall when the recirc hose is on, because then it's keeping all that air in the system.

I'll do some more tinkering with the BOV adjustment tonight and see what happens. I'll have access to my friend's vacuum pump as well, so I'm not just 'eye-balling' it.

Or he could get a HKS SSQV. Those BOV's are draw thru friendly.

Very true! Or he could get a Synapse, as it's also draw thru friendly It's also not as obvious

^ I thought about that actually...that, or the Synapse. But I don't really want to go through all the trouble of having to change the BOV flange and all that.

Hell changing the flange is easy enough. Cut the old one off, and have a shop weld on the new one in the same exact place

He's happy with his Greddy Type S, let him be. =]

Also, BOVs are insanely expensive. You guys toss around Synapse and HKS SSQV like it ain't no thang.
There's no reason to spend more than $50 on a 1G DSM BOV or $45 on a Bosch diverter valve (if you plan on staying recirculated) if you're running low boost.
There's no reason to spend any money at all if your current BOV is workign fine and you're happy with it.

I'd recommend keeping the recirculation just because the car will run better, and that's my style (sleeper). If you want to vent to atmosphere, more power to yah, just do it right.

And while we're on the topic of expensive BOVs, if I ever decide to upgrade I'm going Tial all the way.