I ran 30psi boost on my T34 on my 3door for at least 10,000 HARD miles with no dumpvalve and was no noticable damage or wear.

Real main reason for DVs in the first place was to muffle the chatter noise.

Then atmo ones started being sold to people who liked that noise.

Im going to run DVs on the GTR even tho i dont like the noise because the turbo is an enourmous one rated to 950bhp and will be running at least 30psi and i dont want to risk breaking it...