Last week I had the muffler eliminated on my recently acquired '91 CTD w/ 3" exhaust. Initially it sounded cool, but the drone at low speeds and around town makes my ears ring after a bit, even with the windows up. It's kinda getting annoying. Now I know that a lot of guys go with a Donaldson muffler, how much are they? Who makes a resonably priced straight-through muffler that would flow like straight-pipe but not the drone/resonance of it?

 

DanMan,

Check out Stan's Headers in Auburn, WA. Their website is: http://www.stans-headers.com/. I don't recall the price off the top of my head but, their exhaust kits use the Donaldson straight-through muffler and according to Stan, the 4" Donaldson outflows a 3" straight-pipe on a flowmeter. You can purchase it from them. It's the same mufflers on the big rigs and I've been happy since I installed it.

Aloha,
Matt

 

Did you also x the resonator? I xed the muffler on my 01 but not the resonator and it's quiet inside the cab.
Summit has some big ID Bullet mufflers that are straight thru and inexpensive.

 

i have an areoturbine a bit spendy but we checked aginst a strait pipe and it actually performs better and isnt near as annoying

 

http://www.aeroexhaust.com/ here is a website you can see them on if your interested

 

Resonator, cat, all that junk was gone when I got it-thankfully. There was just a big muffler. I really didn't think it'd have this much resonance/drone at low speeds, the again, I've never heard a straight-piped Cummins before lol.

That Aero does look like a nice muffler, but $289 is a bit steep right now. I've been lookin at Stan's stuff and would love the 4" system but $$$. The muffler alone is $150. I was hopin to find something for under $100, but maybe what I'm looking for can't be had for that.

 

4"straight mufflers are available. Someone on ebay had them a few weeks ago in the $60 range.

The 1stGens only had a muffler- no resonator, cat or any of that. the crush over the tailpipe takes the place of the resonator.

Daniel

 

the best straight thru muffler is none at all

 

What's a good muffler for my '90? Basically I want this to be as quiet as possible at highway speeds (10,000+ miles per month of loud-as-hell diesel would probably make me deaf in no time...)

Right now the exhaust is fine up until the muffler, behind the cab, but the rest of it was whacked off at some point. I'm not going to be doing any huge mods to this truck, but if bigger exhaust will help by itself, should I replace the whole thing?

 

My truck came with a Vortex straight-thru(also Cherry Bomb stamped into it, so I don't know if that's expensive or cheap - probably cheap), with stock 3". Haven't actually measured the exhaust, I assume stock...anyways, it's only about 1 ft long, about 9" wide, and does not have that drone effect(or it would be outta there!). Has just the right amount of tone w/o annoying resonance to me. Have driven it 8,000mi, half of that at all-day long highway speeds and never bothers me. Bear in mind I probably DO like my trucks a bit more quiet than most, ok? I should imagine an entire exhaust larger size would both change the sound(deepen it?) and give you some performance/lower EGT gains. If mine was needing major exhaust work, I'd go complete 4" I think. :-)

 

I went to a TSC Farm store and got tractor muffler for a Int tractor with 3"
inlet & outlets, went to mc'Rileys and got adapters so I could adapt the ends to slip over the exhuast pipes.
Had a buddy who had a straight cutting torch cut out the washer restricter out.
That was what looked like a big washer with about a 1.5 inch hole.

Whole project cost less than $40.

I just coudn't stand to have to pay what they wanted for a new muffler.

Tom

 

That's a great idea Tom, how does it sound?

 

I bought the Donaldson they sell on airflo.com it was straight thru 4"
:-)
its real quiet, but the turbo sound is real loud :-O

 

I custom built my 4 in exhaust using 90 degree elbows and 4in pipe from Western Star parts store. When it came to a muffler flow master50 series... oval .18 inches long 4and1/4 inches high 4 inches inlet 4 in outlet ....2 small diverters inside deep tone with no drone no restriction and great turbo about $165 CDN 2 years ago.