best flow through mufflers

[Matt400]

I want to go with the donanlson muffler. What do I need for a 2003. Is my stock muffler 4" in and 4 " out or do I have to buy a down pipe that goes from 3. 5" to 4". Thanks

I did that to my 03, What I did was:

• Banks 4" down pipe
  
• 4" straight pipe back to muffler
  
• Donaldson M090544
  
• Stock tail pipe
  

Banks has the down pipes for with or without cat, I did the "without".

You will notice the OEM muffler inlet and outlet are off set so you would think the M090544 would not line up proper however the Banks down pipe with a straight 4" section lines up the muffler with the OEM tail pipe.



A muffler shop did mine and they did not do any pipe bending. They took everything off except for the tail pipe and then bolted in the down pipe, straight pipe & muffler.

 

[JRG]

3. 5" reducer & muffler & a couple clamps. Maybe a beer or 2.



JRG

 

[Matt400]

M100580

Weird how time flys by... I get the urge to do a little muffler searching and find this M100580 and say to myself- never heard of that one yet here it is posted right here and I even replied to it.

In looking at the numbers for this muffler it become more obvious why he chose it. The flow vs noise numbers are the best I have seen. This muffler flows much better than the popular M090544 while being more quiet, I might have to give it a try.

 

[FJfonda]

Cat stuck in the pipe?

Drone --- the free flow demon. I have a Donaldson M085171 in place of the stock muffler and had terrible ear splitting drone. This is the 40" version of the muffler referred to earlier. Added a silverline glasspack before it (in place of the cat) and drone is better but at full boost the exhaust screams like a tortured cat. Without the Smarty Jr, the drone is still evident, with the Jr on level 1 it is bearable. At this point I would purchase a turbo back system if someone would guarantee no drone as I am tired of laying under the truck with the sawzall. I also tried extending the tip 4" and it did not make a difference.

Every time I see a gen 3 with performance exhaust I ask the owner their opinion on cab noise and drone. Most say the dreaded 2100-2200 drone is worse with aftermarket exhaust. Those that tow say it is a real pita.

Interesting note: I called Donaldson to ask about the screaming cat syndrome at full boost and the tech guy asked about the exhaust CFM the 5. 9 flows... when I said I didn't know, he pretty much stated that you can't select a muffler without understanding the flow.

 

[steved]

Hmmm, I'm running catless, a aftermarket 304 SS exhaust, and a Magnaflow 30"... the only thing OE on my exhaust is the downpipe.

I get no drone... towing, empty, or otherwise WOT.

 

[Matt400]

the tech guy asked about the exhaust CFM the 5. 9 flows... when I said I didn't know, he pretty much stated that you can't select a muffler without understanding the flow.

Call em back and say 1700 CFM to see what he says. I may be wrong but a 5. 9 turbocharged intercooled spinning at 3000 rpm shows just under that with the available online calculators. I would like to know what he says about the M100580??

 

[FJfonda]

Call em back and say 1700 CFM to see what he says. I may be wrong but a 5. 9 turbocharged intercooled spinning at 3000 rpm shows just under that with the available online calculators. I would like to know what he says about the M100580??

Where did you get to the online calculator?

 

[Matt400]

Where did you get to the online calculator?

Never know how accurate they are but may be in the ball park. The one I used was this one- calculating cfm. What I didn't know was the VE and ran across that here posted about 1/2 way down the page is 1. 85

4 CYCLE ENGINES

C. F. M. = C. I. D. x R. P. M. x Vol. Eff.

3456

VOLUMETRIC EFFICIENCY:

Diesel Naturally Aspirated = . 85

Turbocharged = 1. 60

Turbocharged - Aftercooled = 1. 85

 

[MMeier]

Running a see through Magnaflow now for about 185k miles, still like it. Also, have a full 4" all the way through.

 

[FJfonda]

Never know how accurate they are but may be in the ball park. The one I used was this one- calculating cfm. What I didn't know was the VE and ran across that here posted about 1/2 way down the page is 1. 85

Thanks --- something to play with.

 

[Matt400]

On the other hand maybe the oem muffler ain't so bad for low noise & decent flow.

The M085421 is a 40" oval muffler spec'd for the 5. 9 Cummins, 6. 6 Dura and 7. 3 Nav with better flow numbers than the popular 51" M090544.



I wonder if that M085421 is the oem muffler or is built the same as oem?

 

[Kubotaorange76]

im wondering this also

 

[DBurkham]

I kept the stock resonator and used a hushpower 4" it is louder than stock but doesn't "drone"... I expected more noise with more flow so I'm happy with it.

 

[TWenske]

I installed a 5" ebay turbo back kit and it had drone really bad. Yesterday I installed the Donaldson M100580 and I am very happy with it. The drone is gone and the wife is happy!!!

 

[Stab]

Real happy with my Pinnacle Exhaust. Hardly any drone. Jerry's a straight up guy with resonable prices.



Pinnacle Performance Diesel Exhaust Systems

 

[Linedog]

I have the Silent Might by rokktech.com I think it quieter than
stock and it is a through muffler egt went down also

 

[RShipp]

Hmmm, I'm running catless, a aftermarket 304 SS exhaust, and a Magnaflow 30"... the only thing OE on my exhaust is the downpipe.



I get no drone... towing, empty, or otherwise WOT.

I too have the 30" Magnaflow muffler. I went with a 5 in. stack to reduce EGTs further and I swear it is just as quiet as stock while cruising. A little louder at WOT and towing, but no drone.

 

[CurtLee]

Real happy with my Pinnacle Exhaust. Hardly any drone. Jerry's a straight up guy with resonable prices.



Pinnacle Performance Diesel Exhaust Systems

You haven't tried to get a hold of them recently have you? I've been trying to get a hold of them but none of the numbers i have worked the last time i tryied to call them.



As far as the exhaust goes they've got a very nice system. I took my time when installing it and like the results.