What your hearing is an open o2 dump. dummies

blow off valve vent the intake air between shift to help not spin the turbo or in some cases supercharger backwards(bad) wastegate is on the exhaust side venting excess boost without them the turbo would keep building boost until it blew up or the engine did

what is the difference from a blow off value and a wastegate?

woa. nice sleeper

SLEEPER!

its very nice man keep up the work love the auto

Yes, but the valve body has been modded with a shift kit and upgraded end clutches.

is it auto tranny?

Love that sound. I got a 1G and now I want an external wastegate!