Muffler installation with db comparison

[Heath_h49008]

Ok... one MONTH to get the job done. (Seriously, it took 1/2 an hour and I was dawdling.)

I have video before and after with audio. I'm going to upload once I figure out which camera caught the best audio.

As you will see, I didn't shorten the pipe after I cut it. The extra 18"-20" doesn't look out of place, and the added benefit of the distance from the cab was huge. You can talk in a normal voice inside. For those who are concerned, I think I captured an appropriate amount of "whistle" even with the muffler. It just cut the high pitched chatter and pop out of the exhaust noise.

 

[Heath_h49008]

Before....

http://youtu.be/0KYOMCI3vHU

 

[212sparky]

What model did you use?

 

[Heath_h49008]

After....
http://youtu.be/i2D_f5yiPR4



Honestly, I think the sheet metal rattles louder than the exhaust, but the sound inside the cab was dramatically reduced. I'm just wondering If I'll get sick of the pipe sitting that high and cut some off.

I hope this helps folks on the fence.

The biggest take-away from this is how noticeable the whistle from the turbo is in the "Post Muffler" recording. The way sound works, only the loudest sound is really able to be picked up by the mic or the ear. The rest of the exhaust was muffled enough to clearly hear the turbo at idle.

 

[Heath_h49008]

What model did you use?

Donaldson M070028

The guys in the beginning of the thread gave the numbers data as to how much the dB was reduced, but this is a pretty good audio of before and after to help put it into perspective.

 

[3rdaavbn]

I regret to say that I did not measure DB levels after installing my Dynomax. However, on the drive to Zout's last weekend, I was able to yell conversations with my two daughters which of course before was impossible.

 

[TehTDK]

Heath, might just be my hearing but I can't honestly hear that much of a difference on the before and after shot of the exhaust install.

 

[dikwks]

Just installed the Donaldson today. Thanks for the info and inspiration everybody. I had originally gotten the Napa equivalent ( it is listed as a resonator), but didn't like the way it was constructed. It was straight through and the body had sloppy welds that would have needed dressing. The Donaldson was cheaper from a local big truck place and it was built way better. Nice beefy metal and smooth welded seams. Man it made a difference in the sound!! No db readings, but it is a real noticeable difference. And no pics yet, it is still silver-ish. Anybody ever notice pyro temps higher? My temps seem to be a little hotter and climb a little faster. But lovin' the sound (or lack thereof) so far.

 

[212sparky]

Where are you guys sourcing these from. Napa is a no go, since they claim they can't get any thing like it.

 

[shenkmen]

Where are you guys sourcing these from. Napa is a no go, since they claim they can't get any thing like it.

I was jerked around by two online stores for my Donaldson and finally got it from local Cat dealer.

 

[dikwks]

Truck Enterprises in Chesapeake VA. It was cheaper than NAPA and it came in 4 days. Big truck places seem to be the ticket.

 

[brianp454]

I've been digging around and considering the Aero Turbine and Flowmaster muffler.

 

[welldigger]

View attachment 472853

I've been digging around and considering the Aero Turbine and Flowmaster muffler.

The aero turbine 3535 is awesome. Fits neatly between the fender and the stack brace. Pretty impressive sound reduction for such a small full flow muffler.

 

[brianp454]

Manufacturer	Part Number	Inlet	Outlet	Body Dia.	Body Length	Overall Length	Price	Notes
Aero Exhaust Turbine	AT3535	3.5	3.5	6	12	20	$ 100	Straight thru design twist baffle, polished stainless
Aero Exhaust Turbine	AT3535XL	3.5	3.5	6	18	26	$ 120	Straight thru design twist baffle, polished stainless
Dynomax Race Bullet	24247	3.5	3.5	5	12	16.5	$ 70	Glass-wrap perforated tube, stainless
Dynomax Ultra Flo	17224	3.5	3.5	6	16	21	$ 75	Glass-wrap perforated tube, stainless
FLO-PRO Twister F4	41288	3.5	3.5	4	12	18	$ 60	Spiral design
FLO-PRO Twister F4	41788	3.5	3.5	4	17	23	?	Spiral design
FLO-PRO Twister F5	51288	3.5	3.5	5	12	18	$ 72	Spiral design
FLO-PRO Twister F5	51788	3.5	3.5	5	17	23	?	Spiral design
Flowmaster Pro Series	13512100	3.5	3.5	6	12	19	$ 150	Straight thru design, stainless
Flowmaster Pro Series	13516100	3.5	3.5	6	16	23	$ 180	Straight thru design, stainless
Moroso	94052	3.5	3.5	4	12	16	$ 60	Straight-through baffled, steel
Moroso	94056	3.5	3.5	4	12	16	$ 106	Straight-through baffled, stainless steel, olished
Patriot Exhaust	H3840	3.5	3.5	N/A	N/A	12.5	$ 36	Insert, louvered core
Patriot Exhaust	H3843	3.5	3.5	N/A	N/A	11	$ 21	Insert, auger design
Walker RV \ Donaldson	? \ M070050	3.5	3.5	7	18	26	$ 50	Perforated tube
Walker RV \ Donaldson	21470 \ M070028	3.5	3.5	7	31	37	$ 50	Perforated tube, Replaces Part Number M353570

 

[welldigger]

To clarify the aero turbine isn't a twist baffle like the twister mufflers and similar designs. It has an air foil shaped baffle. I don't know if that matters one way or another but the construction is quite different than most other mufflers.

 

[Merc1973]

To clarify the aero turbine isn't a twist baffle like the twister mufflers and similar designs. It has an air foil shaped baffle. I don't know if that matters one way or another but the construction is quite different than most other mufflers.

Can you post a video for sound?

 

[Katahdin]

I recently learned there's "now an app" for decibel meters, so I downloaded "Sound Meter' for my Samsung Galaxy S4 and fired up the deuce.

At idle, standing outside the exhaust stack, the Sound Meter dial fluctuated between 83 and 84 decibels. (C turbo muffled with the Donaldson M07002 I'm sure Sound Meter is not as sophisticated as a professionally calibrated sound instrument, but it does seem to confirm MO MV Man's readings on the Donaldson.

In the hard top cab, which I've stripped of foam while I'm refurbishing it, the sound reading also was 83/84 decibels. I plan to test again once I've reinstalled the foam padding, I have several GI ground pads on order for this.

 

[bonedoc]

I have to do some work on the muffler on my deuce. It works perfectly and makes driving much more pleasant. It was installed by previous owner and was told it was a Donaldson but I don't know which one. What I need to do is disassemble it and try to re-assemble it straighter. I'm hoping it is just adjusting the brackets. It leans back and is an issue as I want to install a snorkel kit and want to be able to brace it on the exhaust and don't want that to lean as well.