my motor just got rebuilt and we also put canton VC's on with a breather on each side, im only seeing like 2-3" of vac on my gauge were before it was rebuilt i was seeing at least 12-13, is it from the breathers being on or possible vac leak somehwere? we also dropped the CR to 9:5:1 to be a lil more boost friendly if that makes a diff?

 

Amount of vac you see will range dramatically depending on the valve train setup you have. However, I would say that if you are getting a true 2 - 3, that there is a problem somewhere.

 

2-3" of vacuum would make your computer think it's WOT all the time - not good at all. Do you have a scanner to get PCM data? I'm curious what your BAR and MAP readings are. From what I've read on Fred's page, the BAR minus MAP is the amount of vacuum you have - so if the BAR and MAP are reading consistent with 2-3" of vacuum it atleast rules out the vacuum gauge being bad. What RPM are you idling at?

 

He has a blower... his MAP readings are not going to be the same as a normally aspirated car. Appears the blower may be close to pressurizing the intake manifold at idle. What did you do with the PCV connection?

You would probably get better results asking this on the Forced Induction forum.