Maximizing Muffler Output
 

Maximizing Muffler Output

Started by Glennman, September 22, 2019, 09:18:19 PM

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Glennman

In bouncing off the thread from a while back about the gentleman who had the top of his MCI muffler top cut open, baffles removed or otherwise opened up, then welded back shut, and how it gave him more horse power and helped with his overheating issues, I'm sharing my experience on this.

I commented on how I drilled a 4" round hole next to the tail exhaust of the muffler to open up the flow. Well, I just today welded in the new 4" elbows (one in the new hole, the other onto the original 4" outlet). It hardly raised the noise level at all, but doubled the output. The air feels like it comes out at the same pressure from both holes. Sounds good, runs good. I drove a bit, but didn't notice any measurable difference, but I'll be heading over the mountains next weekend. I'm hoping I'll have the same result as the other gentleman.

Scott & Heather

Or you can just throw on a stainless aero and call it a day :)

https://youtu.be/w4nI3y-YXiE
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

muldoonman

Sounds good, Scott. As soon as I get all the other work on the bus finished that will be next in line.  My 8V92TA has about 95,000 miles on it and is ready. Is that the   AT3535 or the medium AT5050XL??  8)[img]

edvanland

I was in on that muffler cut out then we just took that big muffler off my MCI & with a 8v92 and put on a resonator and straight pipe out the side. What a difference runs better cooler and pulls the hills better wish I had known about that long time ago.
Ed Van
MCI 7
Cornville, AZ

Glennman

If this change I made makes any difference, I might consider the straight pipe with resonator. I have about $65.00 into my 2 tailpipe elbows, so no big thing to rip it all out and go all the way. Thanks all!!!

Lin

Scott, is that your bus with the Aero muffler?  Did you see improved performance?
You don't have to believe everything you think.

edvanland

You will need the elbows so no waste of money
Ed Van
MCI 7
Cornville, AZ

Glennman

The main exhaust off the turbo is 5+ inches, and the two tail pipes are 4 inch, so it was reduced down from 5 to 4, not counting all the maneuvering within the muffler to get to the final 4 inch tail pipe. It was quite restricted. If I was to go with a straight pipe with a resonator, I would need all 5 inch parts. But that's ok!

Glennman

Scott & Heather

Yes that's my coach with the Aero. I cannot remember which one it was. But it fits perfectly. I tried searching my emails for the order but can't find it.
Scott & Heather
1984 MCI 9 6V92-turbo with 9 inch roof raise (SOLD)
1992 MCI 102C3 8v92-turbo with 8 inch roof raise CURRENT HOME
Click link for 900 photos of our 1st bus conversion:
https://goo.gl/photos/GVtNRniG2RBXPuXW9

DoubleEagle

Walter
Dayton, Ohio
1975 Silvereagle Model 05, 8V71, 4 speed Spicer
1982 Eagle Model 10, 6V92, 5 speed Spicer
1984 Eagle Model 10, 6V92 w/Jacobs, Allison HT740
1994 Eagle Model 15-45, Series 60 w/Jacobs, HT746

Fred Mc

So would this work with an 8/71 in a PD 4106 .It would be nice to get rid of that big muffler in the engine comparment. It would also reduce the heat in the compartment. What are the downsides to this.

DoubleEagle

I don't know the 4106 setup, but it is still a 8V71, so either you use two four inch resonators  or one 5". It will definitely take up less room, be a little bit louder, but there should be less heat, especially if you wrap them.
Walter
Dayton, Ohio
1975 Silvereagle Model 05, 8V71, 4 speed Spicer
1982 Eagle Model 10, 6V92, 5 speed Spicer
1984 Eagle Model 10, 6V92 w/Jacobs, Allison HT740
1994 Eagle Model 15-45, Series 60 w/Jacobs, HT746

Fred Mc

Where is a good place (. I.e. Reasonably price) to buy the pipe/elbows?

Thx.
Fred

TomC

Anywhere the shop does big rig exhaust.
Tom & Donna Christman. 1985 Kenworth 40ft Super C with garage. '77 AMGeneral 10240B; 8V-71TATAIC V730.