i dunno guys.. It holds boost nicely, then suddenly drops and almost holds a lower setting.. It's too sudden and neat to be the actuator spring. Rob might be a silly question, but you've unplugged all the factory boost solenoids and crap haven't ya.. try a bleed valve and see what happens.. i would have thought the spring would drop off boost slowly as it struggles to hold it, not just drop it from 13 to 11psi instantly.