I have a Dump valve on my Stage 1 cossie, soon to be stage 3. ill be fitting the dump value when i go stage 3,

I do like the Chatter better then the DV sound,,,, but DV's are ment to reduce turbo lag on gear changes as it keep the turbo spinning.

Better to be safe then sorry !

With out a DV it can f$ck the blade up, as they (may) break ! ! !