@bnz500 haha, You're funny :) When you take your foot off the accelerator, the consequent back pressure forces the air back through the turbine blades. The more technical term for this is 'cavitation', which places enormous loads on the turbo and can or more than likely WILL lead to premature wear of the turbo bearings and other load-bearing components. Have a good day.
@mydogzty /watch?v=7Laz-O3BMEM&feature=related That is a Dose! a flutter just makes that noise you are hearing there, a dose is higher and sounds better, depends what car it is on.
