Hey folks, so I've got the 4" exhaust system on order, and was cyphering which muffler to get. I've seen reference to the Donaldson brand as being quiet while still free-breathing. Some have even mentioned going with the 4" in/out 8.5" x 34" muffler combined with the matching resonator for the best of both worlds.

Without getting into prices, the resonator is about $3 more than the muffler. Looking at the two, it appears the resonator may just be a short version of the bigger muffler (I'm not sure of the internal construction of the resonator).

Why not save $3 and just run two of the full-size mufflers (in series)? It seems it'd be much quieter.

There's a world of room under there (ClubCab w/8' bed).



For comparison purposes; Muffler (Link) and Resonator (Link)


Anybody care to comment?

 

stright pipe it, you wont be disapointed, unless you haul horses or something. i can carry a convo and listen to teh stock radio just fine in my single cab

 

don't get that muffler, it doesn't flow well...

forrest

 

Soooo, . . . . . .. you would suggest?

Lemme dig around in here; http://www.fleetguard.com/fleet/pdfs...mminsturbo.pdf

 

I dug through the donaldson catalog one time and compared numbers w/ the mufflers on airflowonline. that one didn't flow well. I think the one for the Detroits was decent. just go to the donaldson online catalog, and look at the flow numbers.

Forrest

 

Arrrgg!! Danged fine print!!

I wish the Donaldson cat was more descript! https://dynamic.donaldson.com/webc/W...?section=10210

They use estimates for the noise reduction figures. And to top it off, they present with a wide range (10 to 15 db for example). Those of you familiar with the decibel notation system know that a 3db change amounts to a doubling or halving of acoustic power.

With that, the noise reduction estimates Donaldson gives, cover a couple city blocks.


DOH! And no pictures.

 

Id put a magnaflow on it if ur not gonna straight pipe it later.

 

Well, for now I reckon it'll be straight-piped till I can figure out what I'm gonna do.

Thanks again folks.

 

str8 pipe > *

 

Just so it's been asked, what are you comparing it to?

According to Donaldson, that particular model https://dynamic.donaldson.com/webc/W...tml?item=22723

Flows:

It appears to flow pretty good compared to others they manufacture. NOISE wise, it doesn't do so well.

I did an attribute search of their products and found that, looking at the style-1 (round body, centered in/out), 4" in/out, they averaged just under 1000cfm (LR cfm) to around 1800 or 1900cfm (HR cfm). Those higher flowing models presented with an average of around 10 to 14 db of attenuation. If one wants a quieter rig [15 to 20db attenuation (or more)], those upper numbers are gonna drop an average of 200 to 300cfm (those are best guess averages by the way )




Hmmmmm. . .. . . .





FYI: my search; https://dynamic.donaldson.com/webc/W...tr_max_rows=73

 

maybe I was looking at 5" models and compared the flow on that 4" to them? sorry... also, I was looking at 51" models, not 40"ers

just get the 51" model w/ the highest flow... if you're not happy, run a resonator in front of it...

personally, I'd just run it straight!

 

The 5" do take a big jump in flow compared to the 4".

Still digging.

 

Good informative reading (albeit on a little larger engines )

http://www.ashraeregion7.org/tc26/pa...st_Control.pdf