boost/mbc question

When I first got my car, it already had a greddy MBC. I used to be able to turn it all the way down to less than 8 psi. Now since gas prices are sky high, I tried turning it down... But now it won't boost anything less than 10-11 with the controller cranked all the way down as far as it can go. Also before to get down to 8 psi I didn't even have to crank it all the way down. anyone have any ideas what's going on here???
thanks

--Edit-- forgot to say it before anyone asks... no I'm not going by the stock boost gauge, it's an aftermarket.

having your boost turned down to 8 psi won't make a difference on your gas mileage in normal driving conditions. Whether you have it set at 8 or 14, you won't start using more fuel unless you go wide open throttle and you start going past 8 psi, but that takes a second for it to do so. Cruising and normal acceleration boost levels will not affect your gas mileage, this is the beauty of turbos since you have to spool them, which then the MAS sees more air, which then the ECU tells the fuel components to dump more fuel.

Hmm a few thoughts...

1 would be boost leaks which could skew your gauges numbers a bit.


2) possibly a kink or pinch in the boost gauge hose (can cause errors and make it show boost 2-3psi higher)

I'd pressure test and check your boost line to make sure it is free flowing.

vac/boost leak

Get your intake pressure tested, probably hte first thing you should do once you buy a TT/VR4. Mine had oogles of leaks, all fixed now I think.