I have a universal BOV on my vortech SC, and i'm when shifting in boost it doesn't release air (don't hear the woosh). I've played with the "soft-hard" setting with no change. I've noticed that vortech sells a bypass valve (not a BOV), so i'm thinking I've gone about it all wrong. Do I need a bypass valve instead of a BOV? Any recommendations on where to get one? Car will never run more than 10psi if that matters.

Thanks,
James

 

BOV requires boost to the face of the valve, and manifold vacuum to to the diaphragm in order to open. So it's only going to open when you're in boost and chop the throttle and get manifold vac. BOVs have differentt springs for different elevations too to help dial them in.

 

I'm hearing the air (remaining boost) bouncing back and forth between the throttle blade and impeller... tuh tuh tuh tuh, but BOV won't open.

 

A bypass valve is a vacuum-actuated valve designed to release pressure just like a blow off valve but instead of venting into the atmosphere the air pressure is re-circulated back into the intake before the turbo. I believe they are used with really big turbos to help with turbo lag.

 

Bench test the BOV.
Pull vacuum on it with a hand pump (or an idling engine) and see how much pressure it takes to push the valve open with your thumbs. It might be jammed or leaking vac or something.

 

when I rec'd my 2nd BOV, it didn't work. I had to disassemble and reassemble it to make it work. Something was stuck closed on it.....? Works like a champ now.

 

A bypass valve can also be set to vent to atmosphere- I know because I have mine set that way- you just have to make sure your MAF is after it.

A bypass valve and BOV both operate under the same principal being hooked up to the motor but operate in different ways. BOV remains closed until the combination of boost and engine vacuum open it. A bypass remains open until it gets closed by the change in manifold pressure (engine load) and then opens back up when the throttle is released.

Typically bypass valves are used in supercharger applications as you control the amount of boost by the pulley sizes and there isn't a danger of overboosting your motor. And since they only require one vacuum line to hook up are easier IMO to get to work and setup.

 

I don't think the bypass has anything to do with overboost, and should be 100% closed under boost. Its not like a wastegate on a turbo setup. I'm ditching the MAF for SD, so no worries about venting. I definatly noticed a loss in vacuum (I'm assuming because the intake tract now has a good amount of pressure). I've learned the bypass is to releave pressure between the impeller and the throttle blade. I'm going to give the Proflo surge valve a try. Thanks for the responses.

 

Must be it didn't make sense- I said the bypass is used because you don't have to control your boost with a wastegate or BOV since the PULLEYS and RPM determine how much CFM of air your motor sees.

The ProFlo is a good choice- lots of people have had good luck with it.

 

So you meant like this