zboost

Just installed my summit racing exhaust on the cummins 600. And I think I hate it already.... lol. This truck makes ALOT of noise! no straight cat or anything and I believe the "muffler" it includes is actually a glasspack, so that makes it even louder right? I'm already tired of it after 4 hours, its just to loud.... and I like loud cars. Will the aeroturbine quiet it down? I don't have any drone, it just.... LOUD.
thanks!

Andrew k

I would go with a 31" Donaldson or a Nelson. The longer 50+ inch mufflers are good if you want it to be really quiet.

zboost

I keep hearing about these donaldon and nelson muffler.... are they a straght through design? also where can I find them?

HorseHauler

yes they are straight through design, and you can get them at your local freightliner or other big rig shop/dealer

Big Bob

I have the 51" Nelson, 86131M and really like it! Quite inside but a nice deep throaty sound outside.

01350banshee

I just got my Donaldson 41" installed this morning. I Love its deep throaty sound and it is just slightly louder than stock. Driving it now, throttle response seems to be quicker and I see egt's down about 75-100 degrees at 65mph. I recall another persons post that mentioned after putting on the donaldson the vibrations/drone in the truck went away. Well I can honestly say, no more vibrations here also. It took me by complete surprise! Also, no drone at all. The guys at the shop did a bang up job installing it and they made sure that all the stock hangers mounts were reused. Highly recommmend this unit to anyone who does'nt have the extra cash to replace the entire exhaust system or just wants to do a muffler only. I got mine locally (Tukwila, WA) from Airflow Systems for $64.00 and they have them in stock. Cost me an hours labor that included the extra tubing and fabing new hangers.

zboost

Excellent, do you still have your cat on though? Sounds like this 40" donaldson is the way to go.

01350banshee

zboost
http://www.airflowsystems.com/ I paid $64.00 for mine. I have a shop here locally (Tukwila, WA 1-800-255-8853 @ Mike E) about 45 minutes away from my location. So I was able to walk in and see the three units everyone seems to be running. My opinion on the matter is the 41 is a perfect medium between the two. (33/51)

Yes, I left the cat on. I was'nt going to chance removing it. So that if/when I or have to move to a new area that may require emissions checks I would'nt be stuck with needing to find a used unit or spend $800-1000 on a new one. The 41" M085171 (series 1, 11096) seems to be the way to go, it's a straight thru flow muffler with an expansion chamber towards the rear. I was told the 33" flows better but is much louder and the 51 may be to quiet. I've put about 150 miles on it since yesterday morning and I'm nothing but pleased with it. Plus, I saved myself a crap load of money by not having to replace the entire system. As for the sound just slightly louder than stock during daily driving and definately more noticeable when above 2000 rpm, but nothing "I" could'nt live with on a long trip. Just make sure to get the pipe out past the bed and use all the factory mounts. Any other questions just drop me a PM