Shadow Assassin

Just installed Supermaxx header system by Dynatech. Came with hi-flow cats, also installed those. Running sans muffler.

Love all the new noise except the drone. I expected a certain amount of drone and interior rattles, but at 1400-1500 rpm, it is unbearable. Sounds like the worlds biggest nest of hornets trying to drill their way in through my shifter. This is right in my usual rpm driving range, so I have to hear it a lot. It's one of my daily drivers, so this just is not going to work.

Any suggestions? I don't even enjoy driving it now. It sounds like junk.

black01_WS6

iTrader: (13)

check for leaks in the exhaust, and see if the y-pipe is hitting the floorboard, if its barly hitting it can sometimes sound like a drone. a muffler clamp will solve this easiely if its the y-pipe. but it shouldn't have a drone that is unabearable.

Rey Kirkman

My understanding is that there is an inherent exhaust resonance/drone in all Gen III motors at 1400-1600 rpm. GM spent a lot of time and money engineering the drone out on stock exhausts. With straight pipes the drone should be really loud. One aftermarket mfg that seems to be able to attenuate the drone is Corsa, they have GM part numbers for some of their applications. There may be other aftermarket mfgs that can eliminate the drone.
You might consider a baseline dyno with your straight pipes, so you can compare the detriments/benefits of any exhaust change.

neonblack

Put a race style bullet muffler on that bad boy and you should be good to go. The Borla XR-1 seems to be pretty popular around this joint. Most of the sponsors carry them at a reasonable price.

Shadow Assassin

Thanks for all the info and suggestions. Rey, that stuff you posted was really interesting. I had never heard about all that.

We traced out some of the worst of the noise. There were some parts rubbing under there and the expansion of the pipes when it all came up to operating temp was just making it even worse. We got this set up because it was supposed to be specifically for LS1's. But everything you try to squeeze into these cars is tight and requires a little tweaking. I don't know why I should have thought this mod was going to be any different!

I'm going to drive it a bit and see if I can live with what's left of the noise. If not, I guess I'll have to strap a muffler on. I'm really gonna hate that.

SouthFL.02.SS

Straight pipes on these cars sound horrible. Incorporate an X or an H junction into your setup, or go back to a Y and a catback. You'll pick up some scavenging with any of the above metioned anyhow.

1QWIKBIRD

iTrader: (25)

My car had the same problem, even with a muffler system, but after a bullet muffler was installed in the intermediate pipe, the drone is all but gone with not real downside to the performance..