I don't think it does any damage, it didn't do any to mine that I know of and I drove it pretty hard all the time. I had just recently bought it so I had too I couldn't really feel it letting the boost let go but my tuner said it would peak and drop back and then just wouldn't make any more. Sometimes when I'd drop the pedal off and then go back on it wouldn't spool quite as well as it did with a full spool up, if you know what I mean? Even so it still went REAL WELL considering the lack off mods. At the drags it almost coasted from about half way due to the standard injectors running out of legs. My mate reckons he can feel the flapper opening and closing a little when holding WOT. There is somewhere in the tune that controls the speed the boost comes on. We tried setting it so it came on hard but ended up turning it back a bit so my wife didn't kill herself taking it up the shops.