Bov Operation?

[1ViciousGSX]

Originally posted by Matt D.@Jan 27 2004, 12:40 PM
Regardless, if the BOV is opening under vacuum conditions it is only sucking in air, not blowing it out.
It's blowing out because even at idle the turbo is spooling.

[CVD]

It may be spinning a little, but you wont see positive pressure in the IC pipes. With the kind of vacuum present in the system I wouldnt even think it would be possible to have air come out of the bov.

[A//// Guy]

Yea Im stumped I dont know what is going on it seems backward. The vacuum and air blowing out doesnt make sense.

When I reved the engine and held my hand over the BOV outlet it was pushing air out at idle and then during rev it wasnt and then when i let off it pushed out more air than at idle.

[1ViciousGSX]

Originally posted by CVD@Jan 27 2004, 12:57 PM
It may be spinning a little, but you wont see positive pressure in the IC pipes. With the kind of vacuum present in the system I wouldnt even think it would be possible to have air come out of the bov.
There is no vacuum at the UICP. All vacuum is behind the throttle body in the intake manifold. I wouldn't expect to see high pressure air either at idle, but if some air is coming out, then there is pressure behind it, even if it's very little.

[CVD]

There is vacuum in my IC pipes at idle. Enough so that I wouldnt think that my car is unique in this. I really dont think that the exhaust flow at idle is enough to put any pressure into the IC pipes.

[A//// Guy]

So anybody have any suggestions on what is wrong or is this something completely new to alot of people...

Ill talk to Mike tonight.

Can having a bad BOV hurt the engine by not letting out the air?

[Shane@DBPerformance]

Vacuum opens BOVs. If your vacuum is high at idle it can start opening the BOV. There isn't vacuum in the I/C piping, since vacuum is caused by the throttle body. But there is a hose that runs from the intake manifold(where you have vacuum) to the BOV(opens from vacuum). So unplug that annoying line and problem solved. :stick:

[Shane@DBPerformance]

Originally posted by EclipseTurbo@Jan 27 2004, 03:52 PM
Can having a bad BOV hurt the engine by not letting out the air?
No, but it can hurt the turbo.

[A//// Guy]

What does the line from the intake to the top of the BOV do? Does it just aid operation or is ther another purpose. But, so there shouldnt be air blowing out the BOV? What would cause the weird noise its liek a groaning or berp. Not a woosh at all and the turbo sounds weird too now.

[Shane@DBPerformance]

Damn dude, just try a different BOV, I was joking about the hose going to the BOV, it controls the BOV. With the stock intake, piping, and BOV setup it doesn't matter if it's open at idle because it's sucking in metered air.