How often should you replace a muffler?

[luvrbus]

You start buying 5 in fittings and pipe to reroute a muffler if you don't do it yourself it can run into money in a hurry

[belfert]

I priced a muffler for my MCI a few weeks ago and was totally blown away by the price.  It was over $500 for the muffler, straps, and connectors. 
It's just a tin can! 

Heck, MCI wanted over $1000 for the muffler for my Dina!  I spent weeks looking for an alternative and finally found that one company still had a cross reference for the Dina part number.  A number of companies made the muffler over the years because International used it on some trucks, but most have discontinued it.  I couldn't get new straps as I couldn't anyone making 12" oval muffler straps anymore.  (MCI did not have the straps anymore.)  I paid around $400 for the muffler.

I had to replace the muffler because the tail pipe was so rusted it was falling apart at the end.  There was no way I could separate the tail pipe from the muffler due to rust and I might have broken the muffler anyhow.  The muffler was pretty rusty, but not noisy that I could tell.  There was really no space for a different muffler or resonator.  I was able to find a tailpipe that was really, really close to the original for a lot less than MCI wanted for the original.

[HB of CJ]

Could one just gut the bad muffler but keep it in place?  If you have a sweet turbo Detroit 2 stroke, just run the gutted muffler then place a nice approved spark arrestor on the end of the tailpipe?  Would that quiet it down enough ... if you kept your foot out of it in town?  I am thinking about the maximum allowable back pressure on turbo 2 stroke Detroits.  Just me.

[Seangie]

Does it matter what we use?
Can I use any 5" muffler?

like this:  http://www.ebay.com/itm/Flo-Pro-Max-5-Stainless-Steel-Performance-Diesel-Muffler-24-Body-M12774-/161673812201?hash=item25a48298e9:g:mO4AAOSwPhdVLo0L&vxp=mtr

Dave,

That looks like it would work for me.  I've got about 36" of tailpipe that would replace.  As long as it doesn't produce much backpressure.

Maybe the resonator.  But I'll probably be straight piping it by sundown today.

Looks like if I pull the muffler I just need about 2' of flexpipe to hit the tailpipe and that should fix me up for now.  Clamps and hangers are already in place.  Might need one more hanger.

Not many parts needed to make either the resonator or the 24" Flopro work.

Thanks guys.  Hopefully this fixed my issues.

-Sean

[TomC]

Donaldson M120131.

[Scott & Heather]

I had a friend in the metal recycling business in florida who gets
Buses all the time. He called me when he got a 9 in and it had a nearly new muffler. I pulled it off for free and installed it in my coach. Fun. Actually not fun. But quiet.


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[Iceni John]

Could one just gut the bad muffler but keep it in place?  If you have a sweet turbo Detroit 2 stroke, just run the gutted muffler then place a nice approved spark arrestor on the end of the tailpipe?  Would that quiet it down enough ... if you kept your foot out of it in town?  I am thinking about the maximum allowable back pressure on turbo 2 stroke Detroits.  Just me.

I don't know if this 6V92 is completely mufferless, or if it has just a resonator, or what, but it sure sounds good:  https://www.youtube.com/watch?v=Wz_VJB3y89M   I suspect I have the same Donaldson muffler as Tom has  -  it's not loud, but it definitely makes a throaty sound.   Or you could do what my friend Al did with his Crown's 6-71T:  he just performed a radical mufflerectomy and put in a piece of straight pipe instead!

John

[lostagain]

That's what mine sounds like against a wall too. So straight pipe or resonator must be a balance between enjoying the sound and added performance for yourself, and how much you think is OK to aggravate the public with the noise. Much like a loud motorcycle: not everybody thinks it is cool.

JC

[Tom Y]

Anyone looking I have a new old stock, 5" in one end and 5" out on the other. $40.00 but shipping will not be cheap. Tom

[Tikvah]

Tom,
I need one, and I'd be a fool to pass that up.
Where are you located?

[morefire]

What's a muffler?

[Seangie]

So I took the muffler off and installed a 90 degree and now I have a straight pipe. 

First thing Mack (my bus) says to me...  "Bout time bro, mufflers are for girl buses"

It is loud.  Not deafening but I don't need a tachometer to know what my RPMs are.

Jake's are really loud.

Temps are back to normal (best they have ever been)  and my power is back.  Was actually able to get up to the speed limit a few times heading into Junction TX on 10.

I think I'm going to go resonator.  It would be great if you could install a diverter to use a muffler in town and straight pipe on the hwy.

Thanks all.  All that headache back in Montana and all I needed was a muffler.

-Sean

[RoyJ]

Had great success using two Magnaflow style glasspacks on my 6V71. Both 3", rated to flow well over 1000 CFM each. My bus has dual exhaust from the factory, which makes this setup work quite well. I'd be comfortable using it on upto a 8V71N.

I was afraid of them being too loud, especially low frequency drone, but turned out quieter than my old rusted out mufflers (which were none flow-through).

Engine breaths a lot better, and I spend a total of $130 on the mufflers, and maybe another $70 on clamps and 3.5" to 3.0" reducers.

[Tikvah]

I guess Tom's muffler won't work for me.  Mine goes in and out both on the back end of the muffler.

Any other ideas?

[luvrbus]

Rule of thumb Dave a muffler for a DD needs to be 2+ times the CFM of the air cleaner,Donaldson has a formula for figuring it on their web page bigger is better IMO