JRD

Pulled out my Aeroturbine 4040XL yesterday and put in the Donaldson m085171 (4"in/out 40" long body) yesterday. Install was a breeze and I didn't need to use any bends to locate the exhaust properly.

Sound is almost exactly what I was looking for, slight drone in the cab in the midrange but nothing compared to the Aero. The rest of the time it is stock like volume in the cab. I can actually carry on a conversation without raising my voice. Roll the windows down and you can tell its not a stock muffler without the famous 3rd Gen rasp at high RPM. Overall I give it an A- because of the very slight drone at midrange, otherwise it would have had an A+. I have yet to tow with it but I have confidence that it will be leaps and bounds above my Aero. Oh and you can hear the turbo through the exhaust which is always a cool plus Just thought Id give someone more info in case they were in the market for this muffler.

tslewisz

Do you still have a cat?

roughstock

I am in the market for one. Have huge drone, looking for answer.
The muffler on my 4" after market exhaust is only 26 or 28 inch long.
How do you fit the 40" in there. ?

alboy

Leave your muffler and put a resonator in front, Fte has a real good one ,also one of the members on here had a litttle short res from nelson or donaldson fairly cheap with good results.

Fordzilla

I used two resonators in addition to my 36" Magnaflow...I have zero drone and good exhaust tone......Ben

JRD

The 40" muffler fits in there easily. There are people here that have put a 51" Donaldson under there. I just didnt want to have a hot water heater for a muffler. :-) I can post pics of how I did it if needed. Oh and the CAT has been MIA since the truck had 200 miles on it.

Classy5.9

I have choose to do the water heater size! Mine is a megacab though so there is more space under there.

roughstock

Resonator part number?

Troy Tapp

Installed 51" and love it! Still has a nice strong tone and no drone! I've also have 5" pipe.

ramman

Installed 51" and love it! Still has a nice strong tone and no drone! And for less than $100 delivered.

C Schomer

I started with a 51" nelson and it was raspy so I packed it with fiberglass and gave it a deep tone. I'll try the donaldson if I ever do it on a different truck. Then I changed the turbo and got bad drone. I came across completeexhaust.com and got a glasspack to use as a resonator up front and that fixed it. Craig

Asher

I used the 51" with 5" in-out, but then reduced it back down to match up with the 4" tail pipe (it was still cheaper using the adapters then it was to get the 4" muffler).. Works great, quieter inside the cap then the factory, but alittle more outside sound when you step on it... I couldn't ask for a better set up for my needs/wants..

Also the muffler I used is the most commonly used muffler in the semi industry, so they are cheap and everyone has on available if I would happen to need it in a pinch...

dodgebob03

Where did you find the resonators? I'm looking for one for my 5 inch ear exploding exhaust system. Need to tone it down a little (LOT).

raymond21

I've got a 4x40 donaldson, love it!! Gives real good turbo whistle at idle and just off of idle. Has nice tone at highway speed also.