Have any of you guys done a power break, smoked the tires then let off the gas and heard some sound "VVHHH VVHH VVHHH" or something like that..

Been getting the sound more after letting off under slight to hard acceleration.

mine does it as well when towing. Get on it and let off and you get it.:eek:

Wonder if that is a bad thing or its 'ok' or 'normal'

I've never experienced it myself but from what I've read it sounds like you guys are both haveing a case of turbo bark. Apparently this happens when you quickly get off the gas at high rpms or if it runs out of fuel when you're running it hard. Basically the turbo's wheel stops and reverses direction nearly instantly. As you might have guessed the turbo doesn't like this ;)

I don't think the turbo is actually reversing direction, but the differential pressure across the turbo increases by suddenly going from loaded to unloaded. Call it compressor surge. It can cause thrust along the turbo shaft, impacting the bearings and premature wear on the unit...could eventually destroy the turbo.

On a wastegated turbo I would expect the wastegate to open. On a VVT...sounds like to me that the VVT control is a little slow on de-fuel and perhaps this condition is exacerbated by some power adders.

Are you sure is wasn't more like vrhh vrhhh hv hv hv hrrrrrr vhhhh? Cause that would be bad.

What he said...:exactly:

oh trust me wastegated turbos do it too;)

Turbo bark. It sounds like a mixture between a small dog ana 3 stooges woop woop woop right? Sounds cool yet expensive at the same time? Yeah.....thats bad, dont do it.

Just be mindfull about lifting slowly when into the throttle hard.

haha thats funny cause my friend has a f-250 and he holds the brake till the wheels almost brake loose and lets off the gas ....and it sounds like a blow off valve like on the ricers ...is that turbo bark?