When I bought my 07 5.9 new,it had a slight swoosh sound wich seems to be coming out of the exhaust side of the turbo after the tranny shifts and my rpm drop.
now with the aero turbine and stage 11 afe,its very pronounced,what is this?and will it hurt anything?thanx

 

It is normal, Afe stage II plastic.
The "swoosh" sound is the turbulent rapid air/wind from the filter to the turbo.

 

Yep!!!!!!!!!