im on mfi and my chatter is much louder than any dumpvalve (you can hear it if driving along in a car next to it even on the motor way).
ive got an old school piper cross sponge filter (its bloody huge, about the same size as a size 5 football)
the amount of boost your running also affect the amount of chatter, this is because the turbo will stall harder if your runing more boost, and it is the stalling wich cause the sound.
also, running a fmic should make it louder due to making the turbo less restrictive.
im running a stage 3 turbo, 1.4 bar and a race gate actuator (the charateristics of the actuator also affects turbo stall)
obviousely the metering head is going to restrict it slightly but switching to after market management isnt going to make that much difference
