Tonight just for kicks as I was driving around town I had my truck in D2. I was wondering if the truck would sound any different. Man with the BHAF and the truck revving higher,it sounded BAAAAD. Just going around 25-30mph with stop signs and redlights,it seemed to be making some real noise. Anyone else notice this??

 

Mine sounds fine at high RPM. Real smooth and quiet actually.

 

Mine has a low frequency drone that starts at around 1800 rpm. At first I thought it was the drive line, because when you took your foot out of it, the sound stopped. But I tried putting the stock box back on and it went away. So, it must be the air being sucked in that's making the noise.