91civicZ6

All I know is i have a Powerup VENOM Pro Type I BOV. It is adjustable by unscrewing the top and adding washers to raise the spring tension. the instructions said to warm your car up completely so it idles down, and then add or subtract washers until the blow off valve is closed at idle.

Honda16hb

just fyi, bovs do not work on naturally aspirated cars, I have removed mine and covered the hole with duct tape. here's the run down: at idle or any other vacuum situation the bov or whatever the ---- you want to call it is going to be open, unless there is mad spring pressure on it so that the vacuum cannot overcome the spring. this is physics you can't argue it. once vacuum pressure is stopped, or spring tension overcomes vacuum force, the bov will close. when you are boosting and you let off the throttle the throttle plate closes. you are getting vacuum source from the engine side of the throttle plate, the engine will suck in air and since boost is no longer getting into the intake manifold vacuum will be created. the vacuum combined with the boost pressure will open the bov and boost pressure will exit.

On cars with a maf/mas/whatever you want to call it the bov exit pipe is routed into the intake after the maf. if this is not done the maf will see air being drawn in by the turbo and think it needs to dump more fuel, when in fact the air it sees being drawn in is just going into the atmosphere. if you're going to argue with me on this one at least know what the ---- you're talking about, I've read all of maximum boost, I've been a member of this site for about a year and a half, I got the physics award for my graduating class, and I saw the fast and the furious.

iNetForce

lol, I agree bovs let air out of the intake, they dont suck air in.

Honda16hb

I never said they didn't suck air in, it's quite possible that they do suck air in when they're open during vacuum.

d16forlife

What so hard to understand here kids ?

A diverter will suck in air.It has one(1) diaphram and its vacume activated.

A true blow off valve will have two(2) diaphrams and one will open at idle whlie the other one will close to prevent air/debris from getting in to the intake mani.This is typically found on the big brand BOVs.


Im done ...lock this bitch up

Honda16hb

if you're so smart why don't you draw some pictures of this 1 diaphragm vs. 2 diaphragm action. I'm thinking that volvo one you sold me might be a real bov and that's why I can't get it to open when I'm running mad NA vacuum.

stinky

Honda16hb

hahah, what a jackass. I figured it would vent out the rush of air bouncing off the throttle plate when I let off the gas, but no go on that, I guess I'll have to actually get a turbo now.

quadnie

Alright guys, thanks for all the input on BOVs, I hope everyone has a good understanding of them now. I might link this thread to something in the near future.. of course after I clean it up a bit :P

I guess a lock would be in order about now, and it's going to lose it's sticky

We still have another BOV thread open and it's more of the different branding, feel free to share some input on that one.