just installed MBC's, little concerned

[trev]

So I added a set of MBC's per robrobinette.com I have been running 17-18 vac before I added them (I could only boost to 7psi of course) and after I added these, I have it at about 9 psi and the car is measuring 16/17 with a very rare dip to 15 if the idle drops a little. Car is still smooth and runs fantastic...just the haunting thoughts that I could have done something during my couple of boost pulls...any thoughts or am I just being a little too over concerned?

Trev

[josh18_2k]

this may not be the cause at all.. but any good MBC is vented, to prevent boost fluctuation. on mine, there was a small hole drilled into the part with the ball/spring. i'm thinking that the tiny bit of air sucked in through the vent is contributing to your drop in vacuum, and is totally normal.
if im wrong, my bad

[David Jerome]

I wouldnt worry, if it was blown you would know it. Could possibly be loosing a little vacuum where you added all the new lines also.

[SPICcnmFD]

^agreed, IMO vaccum is not a good indicator of engine health since their are so many things that can cause it change.

[trev]

well,

I did swap out the boost control with a new ball bearing controller, but left the needle valve in charge of pre-spool. I am getting a 7-3-5 pattern now...guess I need to tweek it more...