dont listen to what all these guys are saying. ford didnt placed a dv without a reason in the first place. when you rise the boost pressure you want to loose this boost pressure when you get of the trottle. without a dv the boost pressure try's tpo stop the compressor wheel from spinning (rough). this is because the pressure cant go anywhere then going back trough the turbo. and that chatter sound is nothing more then the compressor wheel is chopping air which is forced to go back trough the turbo. well that a healty situation (NOT). dont get me wrong it is a great sound. a dv will take of the strain of the turbo a lot more.

most guys who are saying "i'm driving 3000miles without a dv, no problem"
i say......WTF is 3000miles. its nothing. i'll drive 90000km without problem.
guys who are saying "you only need a dv with a t-4 on high boost" come on guys thats bull shit.

a t-34 on 30psi is spinning also real hard. why putting more stress on a turbo which has a lot of stress allready with 30psi.

wim