'69 Charger with '71 440 30 over. HP manifolds, TTI 2.5" exhaust with H pipe, and Dynomax/Walker 17748 Super Turbo mufflers. Stock style exhaust tips that slip over the pipe. Edelbrock Pro Flo 4 EFI and Crower 32242
Crower 32242 Crower Compu-Pro Performance Level 3 Camshafts | Summit Racing
Johnson lifters, Comp cams double roller timing chain and 911 valve springs. Otherwise stock. Stock '73 727. 8 3/4 rear with open 3.23:1. 27.8" tall tires.
The car runs great but I have this pretty loud and annoying hum from ~1750-2100 rpm, which is most of my driving rpm range through town. Stop and go traffic it sounds great, same when getting the rpms up a little. Light throttle doing 55 it sounds great and not at all too loud, same doing 70 or more, but it will still growl when you push the go pedal down. I tried Dynomax Ultra Flows 17513 and it has the same problem.
I've never had a real drone, I don't think. From what I can tell from others, it's a drill in the skull type of deal. The closest I've encountered like that is when I'm on the highway, with any car, and I close the front windows but not the rear, and it feels like your eardrums are gonna blow.
This is a constant deep hum and goes away as soon as you let off the throttle. It doesn't give you a headache or make anything tremble, it's just obnoxious.
I have some 12" Cherry Bombs I can mount in the tail pipes but I'm not sure that would fix it, and I'd hate to cut the pipes only to find out it was for nothing. Alternatively I could try Walker Quiet mufflers but I only want this hum gone, not the sound it makes throughout the rest of the range.
Any ideas what's going on and how to remedy it?
