All I know is that my dodge straight piped is WAY quieter towing than my 06 duramax with a mbrp 4" exhaust. The duramax was quieter empty, but put a big load behind it and it was real loud in the cab. My dodge is only slightly louder towing and i don't think anyone would call it loud.

 

an angle cut res tip will make a HUGE difference as well. The "drone" comes from sound impulses hitting off the inside of the fender well behind the tire. An angle cut res tip directs most of the sound impulses down and away. I have a straight pipe on mine and it had an unbearable drone until I put the angled res tip on it. It's either that or make sure the entire exhaust tip is protruding out beyond the fender well. Try taking off the tail pipe and let the exhaust ring out right out of the muffler, even a stock muffler, the drone is so bad it'll drive you to drinking.

 

well that is how I feel too. I would not mind a bit more sound outa my truck. I do not want drone or any more annoying noise inside. I have heard trucks that I like and some that I really dont. Problem is I never seem to be able to ask the guys that I like the sound of what they did. Which really would be the best way to make a decision. I have had nice sounding exhaust on gas vehicles that were not loud inside the cab. By reading this thread I am thinking the Donaldson could be what I am looking for. I have no real interest in removing my cat, although we have no laws or anything that say I cant. Sound clips is what we need now.

 

51" donaldson, i tried two straight through mufflers before....towing the drone was unbearable, especially right around 70 mph. The donaldson took away all in cab noise and still has a nice sound outside

 

I don't know about loud, but I gotta think straight piped is just plain loud. I was looking for something for my drone when towing my 5th wheel a while back and came across these recommendations. I ended up doing nothing, but next summer I'll be thinking about it again I'm sure.

This one has has a sound clip...
http://www.rokktech.com/_mgxroot/page_10437.html

This one is suppose to be great in front of the regular muffler for drone...
http://www.flopro.com/Twister.htm

Some sort of flex coupling...
http://www.epiflex.com/epi_diesel.html

There's another muffler from CORSA that is suppose to be drone canceling along with another one I can't find that has arrow shaped baffles welded in it. They garentee that one to work as I recall. Anyone know this one?

 

Anyone have a part number and contact info for where to get one of these mufflers? I would love to lose the drone that I have.
Thanks!

 

BTTT....

 

go to a local big truck dealer.(i went to kenworth) and ask for a donaldson catolog...i picked mine out that way,

You can also search this site for 51" donaldson muffler and get the part number that way...i remember one of the posts having a link that showed the catalog with details

 

for donaldson mufflers go to ryderfleetproducts.com. You will not find a better price.

 

M090544 on the ryder site

 

My 92 is straight piped, and I love it.

I dont think i could straight pipe the 07.... too smooth and quiet to add that much noise.

On thanksgiving weekend I was pulling some rockcrawlers around, pretty heavy load, and I got passed by a 3rd gen that was pulling and probably straight piped. It was so loud I thought a helicopter just landed on my sun roof, and all my windows were up.

Either its too loud or I am getting too old, but i still think its COOL.

 

I was hauling my car trailer with 3 on and got passed by a 3rd gen that was pulling just a sngle car, it HAD to be straight piped sounded great which was why I did mine

 

I put the Donaldson 51 inch on my '06 and cannot tell the difference between stock noise levels and the way it is now. I cannot comment on whether there is increased flow but am putting alot of faith in what I have read here. The consesus on DTR is that it does increase flow. Hope this answers your question about noise anyhow.