Best Muffler to quieten truck without losing Power
06-28-2010, 07:26 PM
#18
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Nelson 86561M, can be used under the bed or as a stack. Makes the highway SO MUCH more tolerable, even when I have it as a stack. Quieter than my 89 with stock exhaust.
http://www.youtube.com/watch?v=KmYFz7WZOKM
http://www.youtube.com/watch?v=KmYFz7WZOKM
06-29-2010, 11:05 AM
#20
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06-29-2010, 05:53 PM
#22
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a buddy of mine made his own baffled muffler. having a single cab 2nd gen with a straight piped short stack made for an annoying road trip. it's really quiet now!! even at WOT he says he can hear the motor over the exhaust 
video before
video after
i love the little shorty turn out he's got on it now. he wants to put a cab height 6" mitre cut on top of it but i told him he should leave it as is. he agreed after looking it over a few more times.
video before
video after
i love the little shorty turn out he's got on it now. he wants to put a cab height 6" mitre cut on top of it but i told him he should leave it as is. he agreed after looking it over a few more times.
06-29-2010, 06:03 PM
#23
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cool, has an interesting sound when starting up. Thats about as far as i got on my internet connection... that is something i was thinking about doing... maybe just come out the pocket and finish my exhaust like it SHOULD be!
06-29-2010, 06:08 PM
#24
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it still has good tone at any RPM, it's just a lot quieter. you can definitely tell it's baffled. if you listen closely, you can hear the sound resonating inside lol.
Edit: he's got a video i'll try to find of a flame coming out of the shorty stack he had before he built the muffler. it was awesome!!
Edit: he's got a video i'll try to find of a flame coming out of the shorty stack he had before he built the muffler. it was awesome!!
06-29-2010, 09:16 PM
#25
1st Generation Admin
For what it's worth, one can cipher what kind of performance one can expect from a given muffler provided one can get some common information from the muffler's maker. The following is how I came to chose an earlier muffler I ran.
With the above, we're moving right at 1332 CFM through the exhaust system at 3000rpm.
In a perfect world, we'd be able to move all that through the plumbing with no restriction. The closest to that is the straight-pipe system.
As far as noise control goes, (note, I have no first hand experience with any of the brand-name systems), straight-through/glass-pack type mufflers (resonators) attenuate high frequency noise. They let the low rumble through. The baffled type mufflers attenuate the low frequency noise. While they do mute the high frequencies some, they also tend to contribute some with the baffles (it's weird science, do a Google). That's why you see both devices on the really quiet vehicles.
OK.
I've found that (outside of the brand-name packaged deals), many kits offer something like this; Muffler 4" In/Out 8.5" Diameter X 34" Body Length (Link).
Note: The rated flow shown, Low, Medium, and High, is at a given back-pressure (resistance to flow). That back-pressure is presented in Inches of Mercury (In Hg). 1 In HG = 0.4911541 psi, or just shy of 1/2 pound pressure.
In the Donaldson product line, that muffler is one of the highest flowing in a four inch pipe system. But it's also one of the loudest at only 8 to 12 db attenuation.
OK
Using the Attribute Search (Link) feature of the Donaldson website, I found one muffler to be the quietest while still maintaining a high flow with the least back-pressure.
This one: M110189 (Link). I call it the BHM (Big Honk'in Muffler)
The specs are:
As you can see, it flows the required volume with under 1 pound back-pressure. AND, it attenuates the low frequency noise 19 to 25 db. A BIG drop in noise.
Now, it IS a Big Honk'in Muffler!
With a gross length of 45.5", and a diameter of just under 12", it's gonna be a close fit under my 1st gen (250 CC long-bed / Your mileage may vary). It's also a Round, Style 2 muffler, meaning it's inlet and outlet are not centered. With that, you'll most likely have to move your pipes a bit to get them to plug in.
Checking with the maker of a muffler you're looking at, they should be able to provide information about a given product such as those used at Donaldson. Plug that information into the above equation to see what it will do in your application.
This is the muffler I currently run ~ https://dynamic.donaldson.com/webc/W...10&item=163863
Hope this helps.
Originally Posted by BC847
Code:
CFM = Engine Displ (cu in) x Full Load RPM x Eff x (Exh Temp F + 460)
C x 941760
CFM = exhaust flow rate in cubic feet per minute
Efficiency = .85 for naturally aspirated engines
Efficiency = 1.4 for turbo-charged engines
Efficiency = 1.2 for engines with scavenging blower
C = 1 for two-cycle engine C = 2 for four-cycle engine
If exhaust temperature is not available, use:
T = 1200F for gasoline engine
T = 900F for diesel engine
In a perfect world, we'd be able to move all that through the plumbing with no restriction. The closest to that is the straight-pipe system.
As far as noise control goes, (note, I have no first hand experience with any of the brand-name systems), straight-through/glass-pack type mufflers (resonators) attenuate high frequency noise. They let the low rumble through. The baffled type mufflers attenuate the low frequency noise. While they do mute the high frequencies some, they also tend to contribute some with the baffles (it's weird science, do a Google). That's why you see both devices on the really quiet vehicles.
OK.
I've found that (outside of the brand-name packaged deals), many kits offer something like this; Muffler 4" In/Out 8.5" Diameter X 34" Body Length (Link).
Code:
Rated Flow LR (CFM): 1800 Rated Flow MR (CFM): 2546 Rated Flow HR (CFM): 3119 Back Press LR (In Hg): 1 Back Press MR (In Hg): 2 Back Press HR (In Hg): 3 Attenuation (dBA): 8-12
In the Donaldson product line, that muffler is one of the highest flowing in a four inch pipe system. But it's also one of the loudest at only 8 to 12 db attenuation.
OK
Using the Attribute Search (Link) feature of the Donaldson website, I found one muffler to be the quietest while still maintaining a high flow with the least back-pressure.
This one: M110189 (Link). I call it the BHM (Big Honk'in Muffler)
The specs are:
Code:
A - Inlet Diameter (Inches): 4 B - Body Diameter (Inches): 11 D - Overall Length (Inches): 41.25 E - Outlet Diameter (Inches): 4 Rated Flow LR (CFM): 1050 Rated Flow MR (CFM): 1485 Rated Flow HR (CFM): 1819 Back Press LR (In Hg): 1 Back Press MR (In Hg): 2 Back Press HR (In Hg): 3 Attenuation (dBA): 19-25 Product Type Description: Muffler, Round, Style 2 Primary Application: FORD MEDIUM DUTY TRUCK Gross Weight in Pounds 35.5 Gross Length in Inches 45.5 Gross Width in Inches 11.8 Gross Height in Inches 11.8 Country of Origin US
Now, it IS a Big Honk'in Muffler!
With a gross length of 45.5", and a diameter of just under 12", it's gonna be a close fit under my 1st gen (250 CC long-bed / Your mileage may vary). It's also a Round, Style 2 muffler, meaning it's inlet and outlet are not centered. With that, you'll most likely have to move your pipes a bit to get them to plug in.
This is the muffler I currently run ~ https://dynamic.donaldson.com/webc/W...10&item=163863
Hope this helps.
06-29-2010, 11:51 PM
#26
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Good point David.
Specs for the 86561M Muffler by Fleetgaurd (originally used on Cummins powered freight trucks, Cats, and Freightliners so far that I've seen):
28" long body, 9" wide, 4" in/out. 1875cfm at 3" Hg, 1580cfm at 2" Hg. Made for Horizontal or Vertical set up (tapered top to let water run off).
I love how bearable it is to ride at 70mph now... all I hear is whistling turbo which may almost be too loud for me now!
Specs for the 86561M Muffler by Fleetgaurd (originally used on Cummins powered freight trucks, Cats, and Freightliners so far that I've seen):
28" long body, 9" wide, 4" in/out. 1875cfm at 3" Hg, 1580cfm at 2" Hg. Made for Horizontal or Vertical set up (tapered top to let water run off).
I love how bearable it is to ride at 70mph now... all I hear is whistling turbo which may almost be too loud for me now!
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