MY 93 SAFF 4X4 HAS DEVELOPED A FAULT WHEN UNDER BOOST , AS THE BOOST CLIMBS IT SEEMS TO GET SERIOUSLY BOOST NOISY THEN STOPS LIKE A BRICK WALL! AT FIRST I THOUGHT ID BLOWN A HOSE BUT SHE HOLDS A LOWISH BOOST NICELY INLY BRICK WALLING AT HIGHER RPM, SHE WAS RUNNING GREAT UNTIL I CHANGED THE COOLER FOR A 70MM AIRTEC 500 JOBBIE AND LOSING THE DUMP VALVE PREVIOUSLY FITTED TO THE TOP OF THE COOLER, IM MORE OF A FAN OF THE WASTEGATE FLUTTER ANYWAY , THE ONLY OTHER DIFFERENCE IS THAT IVE TAKEN THE VALVE OFF AND CAPPED OFF THE PIPE FROM THE INLET THAT WAS PREVIOUSLY RUNNING THE VALVE , BEFORE DOING THIS THE CAR RAN FINE AND BOOSTED FINE AND IS CURRENTLY RUNNING STAGE 1. ANY HELP OR ADVICE WOULD BE GREATLY APPRECIATED IN THIS MATTER SORRY TO BE A BORING TWAT I JUST WANTED YOU TO KNOW THE DETAILS IN FULL! P.S IDLE IS FINE , LOW BOOST IS FINE AND CAR RUNS WELL OTHER THAN THIS HIGHER END FAULT, THANKS IN ADVANCE PEOPLES