Stock muffler looks like good flow?

[Hurroicmedia]

Hey guys I was upgrading to a more free flow exhaust on my fleetwood discovery 37g with a 5.9 cummins isb 300hp. I have removed the stock muffler but I can see through it like it's not that restrictive. I don't. Know much about mufflers and there's no marking on this one but I thought I'd ask to see if this is actually stock or not.

Pics include view from each side and it's about 3 feet long

[twinboat]

Turbocharged engines don't need restrictive mufflers to quiet them down. The turbo does a great job doing that.

I've seen a lot of diesel truck mufflers and that looks like a typical one.

A free flow muffler isn't going to do much when the turbo is the biggest restriction.

[Jim_HiTek]

Saw a cutaway diesel muffler like the one I was buying for my Cummins 5.9 and there were just a few baffles inside. Really didn't seem much more then a tube with a couple vanes in it hardly blocking exhaust flow. I ran with a rusted out muffler (huge holes rusted through it) for a year and you could hardly tell any change in engine noise when I replace it.

[jcussen]

Inside looks the same as an Aero 5050XL resonator.

[FleetMan]

The stock muffler is “straight through” so you can’t do any better than that as far as reducing back pressure. I was going to change mine to a straight through muffler until checked what was on it from the factory - I already had one.

[Kjlunda]

On my old coach, when rust attacked it I took it off and never replaced it. Just a straight pipe in it's place.

[Hurroicmedia]

Thank guys for the replies yeah I already got a replacement straight pipe with a 4 to 5 inch turn down tip. I'll put it together and see how it is worse case I can put this stock one back in but... I probably won't hear the difference much since it's 38 feet behind me lol