After reading the ton of conflicting info over several forums and articles regarding proper bov settings, I have found myself back at square one.

The reason I am asking is because I have some full boost/half throttle inconsistencies. So how do I know if it's properly adjusted? Currently at WOT my car doesn't always make consistent boost. Some pulls it'll hit 22 psi, and then the next pull will make 25 psi like it should. I was informed by a shop it may be because my bov screw is a little too loose and the spring isn't able to maintain the high boost consistently (honestly this doesn't make a ton of sense to me seeing how a bov operates off of vacuum and stays shut when the throttle plate is open, but maybe I just don't understand something, I thought it mainly operated on your vacuum and how much is being pulled at high RPM decel). So at WOT, when I release the throttle I get a clean wooosh sound. If I do a light throttle release I get a little stutter/flutter. Nothing like you hear on the compresssor surge videos though.

So is my valve a little loose? Is the flutter at light throttle release bad? Is there a good way to dial in a bov, and is that good way to basically set it as loose as possible and just tighten it as I go?

Relevant car info: 1996 Evo 4. Stock ic piping. Turbosmart fully recirculated valve. Stock valve train/head. Stock Evo 6 intercooler. Evo 9 turbo. AEM Truboost controller.

I have a small boost leak from the throttle body shaft seal. The car comfortably holds 30 psi for at least a full minute from boost leak testing.

Thanks a ton. Sorry if this is a dumb question, I just couldn't find a well explained answer in regards to my question. I even watched a video where a high performance shop was saying compressor surge isn't that bad and it's worth it cause the sound is great.

 

A stock BOV is open when the engine is idling.
How far open?
Measure it.

An aftermarket BOV should be open by the same amount when idling.
If it's closed, the spring is too tight.

 

Thanks. I no longer have the stock valve (was leaking an awful amount when I purchased the car). To measure it could I set the valve as loose as I can at idle without it opening? And then after I find that point should I tighten it just a tad to make up for the -21ish inhg at decel or leave it at the idle amount?