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Topic: Cummins M11 Exhaust Conversion (Read 1254 times) previous topic - next topic

Cummins M11 Exhaust Conversion

I am wanting to order parts online for the resonator conversion, and was wondering if anyone here would happen to know the dimensional lengths of the 90 and 45 degree pipe extensions used.  There seems to be a couple of different lengths available.  This would be for the 5" exhaust system on an M11 450 hp Cummins.
Thanks, Mike
Mike Brady
'97 U320 SE. #5137
'13 Honda Fit
Willow Springs, MO

Re: Cummins M11 Exhaust Conversion

Reply #1 –
I had the muffler replaced with an Aero 5050XL resonator at a local truck repair place. Here is what they used:

Exhaust hanger (360 degree) EH/TPH21- two used
 
Exhaust clamp EC500 - two used
 
5" stainless exhaust band clamp - 4 used
 
flex exhaust pipe stainless: EF50300S - 2 feet used
 
Exhuast elbow 45 degree EPEL4521DA (steel, they couldn't find stainless)
 
Exhaust pipe downspout (tailpipe) Chrome 50CS1-18C
 
I believe the parts came from a local Peterbuilt dealer.

Re: Cummins M11 Exhaust Conversion

Reply #2 –
I have a 1996 U320 and also replace the muffler and tail pipe.

Muffler:
Magnaflow (30 inches) because Brett Wolf indicated that the Magnaflow is quieter then the 5050XL (30 inches). The 5050XL is quieter and shorter than the 5050 (20 inches). I did not want it to be louder than stock, and it has a deeper tone but is not louder. I read a blog on IRV2 about someone who replaced the stock muffler on a SOB with a 5050XL and after a year of listening to the annoying drone, he replace the 5050XL with a Magnaflow.

The Magnaflow has a 4 inch straight opening with perferations. The 5050XL has two halfs, the first half is like the Magnaflow while the second half splits the exhaust flow and causes half of the exhaust flow to swirl and recombine with the straight through exhaust, which Aero claims reduces the back pressure. Unfortunately, it appears that this swirling also increased the noise.

I replaced everything after the two 90 degree bends welded together and clamped to the turbocharger. I used the following: 15 inches of flex, a short radius 90 degree, Magnaflow, then a short pipe with a 30 degree bend.

I mounted with custom angle iron attached to the OEM muffler mountings.

Another Foretravel owner from BC who I camp with during summer months, replaced the muffler on his U295 (Cummins 8.3) with a straight pipe, but a few weeks later replaced the straight pipe with the Aero 5050 because the straight pipe was too loud. His exhaust is louder than mine.

Most Foreforums members seem to be using the Aero 5050XL.

I also wrapped the exhaust from the turbo to the muffler with heat tape.




Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada

Re: Cummins M11 Exhaust Conversion

Reply #3 –
Quote from: P. Wyatt Sabourin –

Muffler:
Magnaflow (30 inches) because Brett Wolf indicated that the Magnaflow is quieter then the 5050XL (30 inches). The 5050XL is quieter and shorter than the 5050 (20 inches). I did not want it to be louder than stock, and it has a deeper tone but is not louder. I read a blog on IRV2 about someone who replaced the stock muffler on a SOB with a 5050XL and after a year of listening to the annoying drone, he replace the 5050XL with a Magnaflow.

We also replaced our 5050XL with a Magnaflow after one season.  No change in performance from the Aero and we definitely prefer the sound of the Magnaflow.
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Cummins M11 Exhaust Conversion

Reply #4 –
What you need can also be obtained from M&B Enterprises.  They do the install of the Aero mufflers at rallies.  He has a complete trailer of welders, tools etc to does a great install.
Saw one at the last rally and top notch.  Call him for parts and ideas.  520-471-3535
Dan & Shirley Stansel
2002 U295 4020 AGDS Build#6054
Towing Buick Enclave & M &  G Braking
Emerald Bay, Lake Palestine, Texas
MC# 16650

Re: Cummins M11 Exhaust Conversion

Reply #5 –
I used a basic Fleetguard resonator and love the sound. Have had a few truckers comment on how nice it sounds too. It has been on over a year now(maybe more) and no problems.
John H
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Cummins M11 Exhaust Conversion

Reply #6 –
This sounds like a project I could do, what are the benefits of this conversion? Hopefully, the ROI will justify this upgrade.
OH
Rick & Deborah Webster
2002 3610 U320 #5964
2014 Jeep Wrangler Sahara JKU- 'Copperhead'
Richland Chambers Lake, East Texas

Re: Cummins M11 Exhaust Conversion

Reply #7 –
Wonder how the Jack would sound with a resonator?
jor
93 225
95 300
97 270
99 320

Re: Cummins M11 Exhaust Conversion

Reply #8 –
OH,
One never has enough power and never gets enough mpg, but you will enjoy the resonator if your the type that knows your coach.  Some folks can very easy feel additional 50 hp, some could not feel an extra 300 hp, so take your chances.

Re: Cummins M11 Exhaust Conversion

Reply #9 –
Quote from: Old Hippie –
This sounds like a project I could do, what are the benefits of this conversion?

Here's some discussion. 

Resonator and muffler replacement

Installed Aero resonator
Learn every day, but especially from the experiences of others. It's cheaper!  - John C. Bogle

2000 U320 36' non-slide / WildEBeest Rescue
2003 U320

Re: Cummins M11 Exhaust Conversion

Reply #10 –
Quote from: Michelle –
We also replaced our 5050XL with a Magnaflow after one season.  No change in performance from the Aero and we definitely prefer the sound of the Magnaflow.

What number magnaflow?

Bob
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Cummins M11 Exhaust Conversion

Reply #11 –
which one did you guys use?
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)

Re: Cummins M11 Exhaust Conversion

Reply #12 –
thanks Michelle. Lots of information on the subject.
Old Hippie
Rick & Deborah Webster
2002 3610 U320 #5964
2014 Jeep Wrangler Sahara JKU- 'Copperhead'
Richland Chambers Lake, East Texas

Re: Cummins M11 Exhaust Conversion

Reply #13 –
I purchased a MagnaFlow 12774 $160  SS muffler, 5 in, 5 out, 30 long, 7 OD body.

It is available in polished SS at $200 with #14774, however, I wrapped mine with heat tape, so why pay for polishing.
Wyatt
96 U320 40 WTFE, build 4943
84 Toyota Supra towd
2015 Jeep Wrangler towd
Victoria, BC, Canada