Mine comes in tomorrow a.m. Hope to be able to report later tomorrow.

 

Around here Carquest stores won't stock or even order the mufflers. I found a Donaldson at a Stewart and Stevenson service center for $96. I bought it and went to a local Midas shop who instelled it in less than an hour for $80. Unloaded the exhaust is much quieter than the Banks muffler. I am not sure how it compares with stock, it has been too long. I may pull the camper this weekend to check it loaded. There is no droan that I can tell. There is a large arrow on the muffler case near one end that I would normally think shows the direction of flow, but inside the arrow it says "INLET" so the muffler was mounted with the arrow pointing at the engine. The muffler does have the baffle in it. I am not sure which end it is closer to now. A lot of the turbo whistle is gone too. I think I will miss that.

 

I installed the 86131M on mine. I really like the sound and added performance, but I ended up with a little drone and some additional low RPM vibration. After driving it for a while, it felt to me that it was all coming from the exhaust pipe between the turbo and the muffler. I installed a 42" section of 1 1/2" steel angle by making 2 notches that let it bend and conform to the bends in my pipe and then clamping it on to the pipe with a half dozen 5" hose clamps.

Result: vibration and drone appear to be LESS than with the stock system. I have not towed with it yet.

I REALLY like this setup now that I've "tamed" it. Now I want to find a way to stiffen up that section of pipe in a way that is not so "cheesy".

100 Proof

 

I am picking up a Nelson 86131M tomorrow from a Cummins Atlantic dealer. I hope that it helps lower my EGTs when I tow my 33 Ft. 10000 lbs. travel trailer. Then I will think about some kind of air intake system then a box.

 

The M090544 is on. $87 from Carquest, $30 installation, I already had a 4" system. I love it. I think it is quieter than stock, but that has been a while. I also think it is quiter at 85 than 40mph. It does have just a little rumble when starting at moderate speed. I climbed a steep grade hard, before I sounded like a dump truck leaving the gravel pit, now(with the right windows down) I hear a little rushing air sound and the turbo whistle.
Unfortunately I did not check any numbers on the box nor did I look through the muffler, been terribly busy, just forgot those things.
Mine is a short bed, and the muffler starts about 5" behind where the doors meet.
My truck is a Laramie so it might be quieter, seems like it might have more insualation material behind the rear seat. You can see in my photo gallery that I have inslulated the hood. The same bubble foil material is glued to the metal part of all doors and to the inside of all door panels, inside the storage bins, and under the seat and up the back. I redid a '72 and an '81 corvette the same way a while back so I just decided to do the truck when I got it. I also have slush mats over carpert mats. --But with the windows down the muffler is still quiet. sound = stock or less.

 

Another good place to check for one of these is the muffler shop that is going to put it on. My shop had one in there. He aksed how much I paid and his reply was"hmm I must be too cheap" So I asked him if his was a donaldson or nelson, he didn't know and I think it was a 5" anyway. But he might could have ordered just as cheap.

 

I got my Nelson 86131M Friday from a Cummins Atlantic store in Kenly NC right on I-95. It was $79.56. I gad a local muffler shop put it on. He only charged me $30 to take the stock muffler off and weld the Nelson on.
It is quiter at idle and crusing at 60 mph, but when I really get into it the sound is louder. I have not pulled my travel trailer yet, so I don't know if it will be too loud under load. It feels like the turbo spools up a little quicker and it gets up to speed quicker. It is too early to tell if it helps my MPG. I will let you know after I get a few miles on it. My truck is getting very close to 5000 miles.

Bill

 

Well the 51" Donaldson "Silent Partner" was a mistake for me.

Donalson presents it as the most quiet muffler they have in both power and engine braking yet flow of the M101181 is more then enough for the little 5.9, I was sold.
The exhaust note out the tip was ok but the in-cab drone was awful.

I followed up with Donaldson tech support and this was there last email:

Did you buy this muffler with the intention of quieting the engine brake noise? If so this muffler will quiet the high pitch bark associated with a engine brake. If the intention was to use this muffler in place of the current OEM muffler to reduce in cab noise this is not the recommended product. This product is specifically designed to quiet the engine brake and to provide equivalent OEM noise reduction.

Key is whether you are trying to reduce exhaust noise or engine brake noise? If you are not going for the engine brake noise the M090544 and smaller OEM pipe will provide a quieter system.

Using the same Banks 4" down pipe I switched back to a 4" system using a M090544 and my stock tail pipe.

It is more quiet while also a little more loud than stock. But most important the drone is gone.

 

I"m bringing this thread back from the dead. I'm afraid I just gave one of our members some bad information. I was under the impression that the donaldson M090544 did not have baffles, until I read this. Now my donalson came in last week, but I havent picked it up yet. Has anyone heard both a donaldson and nelson for noise comparison.

I read in a recent post about a guy installing a 51" Donaldson, and he said it was straight thru. How could that be when most of you confirmed a baffle.

Anyway, since there has been a lot of inquiry lately about these mufflers, this will be some good reading.

 

the mo85171 muff is nice a little bit throatier than the 51" since its 41" and no baffle i went from the 51" to the 41" and like it much better, still quiet at highway speeds, towing etc, but when you get on it is sound deep and barky .

 

Just wanted to get this thread up to today's part numbers for Nelson if that is possible.

** EDIT!
Talked to Nelson rep and all of these should not be used as they have a cone in them. Can the cone be removed easily? Don't know.
Still researching...
** EDIT!

I found three stainless mufflers from Nelson,

Fleetguard part information for 19067A is listed below.
Part: 19067A
Manufacturer: NELSON
Part Type: Custom Muffler
Material: Stainless Steel
Body Shape: Round
Body Size: 215.9 mm (8.5 in)
Body Length: 873.76 mm (34.4 in)
Overall Length: 1016 mm (40 in)
Inlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Inlet #1 Offset, End View, Horiz: 0 mm (0 in)
Inlet #1 Offset, End View, Vert: 0 mm (0 in)
Inlet #1 Offset, Side View: -63.5 mm (-2.5 in)
Type: 1
Type: 1
Outlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Outlet #1 Offset, End View, Horiz: 0 mm (0 in)
Outlet #1 Offset, End View, Vert: 0 mm (0 in)
Outlet #1 Offset, Side View: 952.5 mm (37.5 in)
Additional Information:
MACK 583919067A

==========================================

Fleetguard part information for 20875A is listed below.
Part: 20875A
Manufacturer: NELSON
Part Type: Round Muffler Type 1
Material: Stainless Steel
Body Shape: Round
Body Size: 215.9 mm (8.5 in)
Body Length: 873.76 mm (34.4 in)
Overall Length: 1016 mm (40 in)
Inlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Inlet #1 Offset, End View, Horiz: 0 mm (0 in)
Inlet #1 Offset, End View, Vert: 0 mm (0 in)
Inlet #1 Offset, Side View: -63.5 mm (-2.5 in)
Type: 1
Type: 1
Outlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Outlet #1 Offset, End View, Horiz: 0 mm (0 in)
Outlet #1 Offset, End View, Vert: 0 mm (0 in)
Outlet #1 Offset, Side View: 952.5 mm (37.5 in)
There is no additional information for this part.

=============================================

Fleetguard part information for 21474A is listed below.
Part: 21474A
Manufacturer: NELSON
Part Type: Round Muffler Type 1
Material: Stainless Steel
Body Shape: Round
Body Size: 215.9 mm (8.5 in)
Body Length: 873.76 mm (34.4 in)
Overall Length: 1016 mm (40 in)
Inlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Inlet #1 Offset, End View, Horiz: 0 mm (0 in)
Inlet #1 Offset, End View, Vert: 0 mm (0 in)
Inlet #1 Offset, Side View: -63.5 mm (-2.5 in)
Type: 1
Type: 1
Outlet #1 Size: 101.73 mm (4.005 in) ID Slotted
Outlet #1 Offset, End View, Horiz: 0 mm (0 in)
Outlet #1 Offset, End View, Vert: 0 mm (0 in)
Outlet #1 Offset, Side View: 952.5 mm (37.5 in)
There is no additional information for this part.

Anyone have any experience with any of these? I'd like to pick one that I can see through without having to bust a deflector out with a pipe.

Thanks!

 

Back to the top.
Best info about exhaust I've found yet. I'm supprised people don't mention these things more often.

 

My Nelson 86131M is 51" and does not have a baffel in it. When you look in one end you can see out the other with no obstruction. I have been satisfied with mine. I can not say for sure if it helped my mpg or not, but I could tell that the turbo spooled up a little faster and the egt is a little lower than it was with the stock muffler. When my truck was new I was getting about 15 mpg. Now I have 23000 on it and have the AFE pro guard 7 and the modified timing sensor and the muffler and the mpg computer flash the mileage has gone up to 18. I do not know if any of these things contributed to the mileage increase or if just breaking it in did the trick.

Bill

 

Thanks for the post Bill!

I checked here

http://www.fleetguard.com/fleet/en/c...fler_index.jsp

and found that muffler. That is on my short list, however I would like to get a stainless steel Nelson muffler that is not as long if possible. Thank you for bringing up that number, I may do it if I cant get the stainless one I'd like (I think I'd also like it a touch louder than that 51 like AK's truck.)

If you get a chance, take a look at the list, there are several Stainless mufflers at least in the mid size length, however I have not heard of anyone having installed one yet. Even though it is 51 inch long, the equalivant of the 86131M in stainless with no baffle would be a good part number to get out there as well. The three part numbers I posted above are all mid length stainless, but none make any mention of having a baffle or not.

 

when looking through the models with no baffel,do they have the open area in them like the baffeled ones?or are they straight fluted from one end to the other?......................bama