GMCtrk

iTrader: (27)

So, the 4" pipe going over my rear axle didn't work out with the drop I have out back. Pipe kept banging on the axle on larger bumps.

So today I hacked off the pipe just after the muffler exit. It's the 24" Magnaflow diesel muffler. Outside the truck doesn't sound any louder, but it drones like mad in the cab now and frankly gives me a headache. Would a turndown after the muffler do any good? Or do I need to look at a different muffler? I miss my Corsa catback. I'd err on the side of quieter sound, as honestly, I much more prefer listening to the turbo sing than loud exhaust.

Mangled03gmc

iTrader: (95)

As long as it is dumped under the truck it is going to give you that sound.

GMCtrk

iTrader: (27)

What sound? Drone? Your post isn't exactly specific or helpful. I know I'm not the only one out there with 4" exiting under the bed. I'm open to suggestions including different mufflers, sizes, and pipe configurations.

Mangled03gmc

iTrader: (95)

The droning sound. It will be there untill you exit the pipe other then under the bed.. 4'' in it self is going to have droning issues because of the dia of the pipe itself..You could possibly add a dynatech turn down tip, it seem to cut down slightly on my drone, rasp issue. I since switched to that huge Edelbrock muffler, the rasp and alot of drone is gone, but not all of it. Your 4'' exhaust is already hushed some because of the turbo..

aldrichg9

iTrader: (1)

I had a single 5 inch all the way out the back when i got my truck and there was no conversations while accelerating. Drone like crazy above 2000 rpms even though it went all the way out the back

Atomic

iTrader: (42)

Add some tailpipe length, mine got a lot quieter after adding a section that went over the axle from the muffler. Its still pointed down about 45 degrees.

oakley6575

iTrader: (5)

He already said over the axle didn't work because of his drop. Is there any space before the muffler to run a resonator or another muffler? You could add a 90* bend after the muffler to make it a side exit before the rear tire. That should help with drone a little.

Atomic

iTrader: (42)

My suggestion is to make it work. This hobby wouldnt be nearly as rewarding if it was easy would it?

black00chev

iTrader: (2)

You could always flatten the pipe over the axle to make for more room. Just make sure to widen it proportionally to not affect flow.

MB2008LTZ

Add a truck load of sound deadener to your cab.....?