I have a 2002 Dodge 3/4 4x4 automatic with a banks power pack. The truck has about 16,000 miles on it. Since it was new and before the banks was installed I cound hear the turbo when it sprooled up. After the banks system was installed the whime got louder when I was under power and accelrating, which I didn't think much of(sounded kinda neat). The other day the sound stopped completely. The boost is the same, the exhaust temp is the same and the performance seems to be the same--just no whine. I've checked the hose conections, the air cleaner to see if it is obstructed in any way or to see if it isn't sealed and everything checks out o. k. The weather is about 20 degrees cooler(from 80 degrees to about 60-65 degrees during the day. My question is does anyone know why this may have happened? Or for that matter why the turbo whines to begin with. I guess if I had that answer then I might be able to figure out why it might have stopped. I don't want to do any damage to any parts and if I have missed something any help would be appricated. As we all know " We are our own Warranty"