Bringing this thread back up, because I think I might have found a very affordable solution.
I have a E350 7.3 EB50 SMB with the 4" turbo back Diamond Eye exhaust without a muffler.
Noticeable drone for about 400 rpm. Usually under load. I use ear plugs to retain what little hearing I have left.
Did some research and came across:
http://www.ftediesel.com/store/pc/viewP ... category=7
All the truck guys on the Cummins forum use it with rave reviews. I just got off the phone with Wally, the owner of FTE. Good dude, usually has resonators in stock and ships right away. He makes his stuff in OH and not from China.
I'm not a great note taker but here's the gist:
Drone (sound and vibration experienced inside the van) is caused by the turbulence from the airflow through your exhaust, causing vibration and our van floor and van cabin act as a speaker for this vibration. Vibration = sound similar to a tuning fork. With his resonator it smooths out the flow of air and thus causes less vibration and sound inside the van. Turbulence starts as soon as air leaves the turbo so he recommends installing the resonator as close to the front as possible. He said his product doesn't do much for sound outside the van. That's what mufflers are for. Also, that's not my concern either. I love how my exhaust sounds outside the van, not so much inside.
Excited to try this out. Will report back once its installed.
Sportsmobile (AKA Money Pit)
Makes me think of Arlo Guthrie
Linear Mode
