RollsCoal

Are any of you guys running the Summit racing 4" ID, 30" oal, 5" body glasspack diesel muffler, PN SUM-630100?

Does anyone know of any data to show how much a straight through designed muffler such as this is capable of flowing at a given inlet pressure? Are they close to flowing what a straight 30" section of pipe will flow, or do they greatly increase resistance to flow compared to plain smooth pipe?

And please don't just tell me to straight pipe it. It is straight piped now and the drone is going to turn me into a Neaderthal.

dieselman2300

To be honest with you, a straight through muffler doesnt do much, if anything. I started straight piped, then installed a Silverline stainless Turbo-back with muffler, and the drone was still there.

I just bought one of these, and everyone seems to love them. Cheap too, only $30 more than the Summit one, and that is with shipping.

http://www.cumminsforum.com/forum/ft...available.html

RollsCoal

Well, it must depend on the truck. I had a straight through louvered style muffler on my 95 before straight piping it. It had no drone whatsoever and was comfortable to drive. Not anymore. Straight piped it has a terrible drone.

dieselpup

Yep, I have the Summit 4 inch. It's louvered, sounds like the muffler you had on 95. I like the way it sounds, no bad drone. Even have it in with louvers facing backwards. It's held up for 6 years now, and I still drive around with passenger window down. What a great sound...

98.5Hotrod

Try the Hushpower muffler. I think it's made by Flow Master.

DaveB.inVa

Its a bit expensive, but you can buy the Corsa muffler that they put in their kit for 3rd gens. I've got the cat back exhaust from them and it sounds great. The muffler is straight through with just a couple inch wide slots at the front and back to do all the noise cancellation.