This a challenging problem.
I have some questions 1st. Do you have a blower bypass valve and is its connections to blower inlet anywhere near the air meter.
This kinda sounds like the bypass valve cycling open and shut at low load causing flow disruptions. If vortech shipped the Bosch bypass with your kit this could be the culprit. Adjustable bypasses are easier to setup for different cams.
To test this pull the vacuum line from the bypass and plug it. Drive the car with low to part throttle (no boost) and see what happens. It will idle funny with the bypass undone because the blower will push more air past the throttle blade. Look for that lean out condition while driving and don't rev it high with out the bypass!! The blower belt could jump off when you shut the throttle.
Hey PKRWUD lets see if we can get this one solved quickly.
Mike
------------------
Live near St.Louis?
Check out Mustang Muscle and Dyno in High Ridge, MO
Check out my
ride.