everyone experiences different things with this wastegate. some people have stated that they creep only when u use a boost controller, which is not tru. ive had some creep like a bitch until i switched on the profec b and it held perfect with no creep ranging all the way from 7-12psi. ron also stated that they only creep at low boost, which im sure has happened but again it is not consistant. i know from my experiences they usually creep at higher boost levels when the extra exhaust gases can not be bypassed thru the wastegate primarily because the valve is just too small. on dougs car anything over 10-11psi would start creeping pretty bad(about 1psi/500rpm). i think its more of the combination of the wastegate with the location of the port on the drag manifold and the one pictured in this thread. they only vent off of the#1 exhaust runner, allowing all the other 3 runners go straight to the turbine causing it to spin faster at higher boost levels where more exhaust gas is producing causing the boost to go even higher as rpms and exhaust gas increase. hope that helps