I have flowmaster A/T's and I think I have a slight drone - a "whirring" noise from 55-65 in fifth gear. At first, I thought it was the Ring and Pinion TSB. Had that done (twice before it was fixed right) and that helped, but the tech said on the repair order that "remaining noise is drone from aftermarket exhaust." I thought that was cop out on their part...until this weekend.

After the ring and pinion was fixed, the sound had me thinking I had a tranny problem in 5th gear instead. As a pre-emptive measure before taking it in, I took the A/T's off and put the stockers back on.

I'll be darned...the noise is about 90% quieter. Still there but I can barely hear it. Whereas, before you couldn't NOT hear it.

I always thought drone was a deep, low-pitch, single note bass-y type sound. Or like the fat chick on Hee-Haw playing the water jug on the bluegrass numbers.

This is more of a higher pitched gear whine kind of noise, that starts medium pitch at 55 and gets a little higher until it fades after 65. Totally sounds like a gear whine problem, but I think I've definitely isolated it to the A/T's.

I really liked the A/T's, but now I'm thinking I should get GTA's instead...

Anyone else experience this with the Flows?

 

Absolutely! Flows drone. My pending question is how much affect, good or bad, will a CAI/tune have on the drone???
I heard, here I think, about someone installing Dynamat on the inside of the doors and under the rear seat to help decrease interior drone.
I would think x-pipe vs. H-pipe would make a difference??

Frankly, I've just got used to it.

 

I was planning on taking off my JLTII for the stock next weekend in returning my car to the dealership for a visit. I will let you know. I also have the Pypes street legal x. That actually helped reduce the drone I experienced below 55. (The lower bass-y drone).

I also have dynamat in the doors and under the rear seat and that did squat for the drone. But sure helped cut wind noise and vibrations...making the drone more obvious.

 

I've noticed that the drone and even the "trumpet" sounds are more apparent inside the car than outside.

 

Nothing like that here... Maybe the clamps were not tight enough or a baffle inside one of the mufflers came loose. Since the mufflers are now off, hit each of them with a rubber mallet. If you hear a "clinging" sound, then it's a baffle. The sound you described dosen't sound like drone. Drone is more of a teeth virbrating lower pitch reverberating bass sound. Ride with someone who owns Stingers and you'll become an expert on what drone sounds like.