Muffler to resonator?

Topic: Muffler to resonator? (Read 1889 times) previous topic - next topic

Muffler to resonator?

March 05, 2017, 09:21:26 pm

While the mechanic was disassembling the engine on our 1993 U300 (DD 6V92TA) he noticed that the muffler had some holes in it, and said that it wouldn't pass a Texas vehicle inspection. We decided that it was more important for him to get the engine taken care of and replacing the muffler could wait. There have been several discussions about replacing the muffler with a resonator, but always on newer coaches.

What might be involved in such a project on my coach? I've been warned that the muffler is heavy. How heavy? How heavy is the resonator? What's the cost of a muffler and a resonator? I do have two hydraulic jacks and can easily build some sort of cradle to support the muffler, then lower it some if it is too heavy. Obviously, I'm not too concerned about damaging the old muffler while I'm in the process of replacing it.

Ideas?

Re: Muffler to resonator?

Reply #1 – March 05, 2017, 09:29:03 pm

Reply #226 and #237:

Resonator and muffler replacement

Re: Muffler to resonator?

Reply #2 – March 06, 2017, 08:35:16 am

Texas inspections check for safety items-horn, brakes, lights, etc. No one climbs underneath or measures db's.

Re: Muffler to resonator?

Reply #3 – March 06, 2017, 09:40:14 pm

Have seen them check a bad muffler on a car or a pickup

but never on a big truck or a motor home, but the dealer

where he was having his work done was trying for a muffler

job, as well, I think.

Carter-

Re: Muffler to resonator?

Reply #4 – March 06, 2017, 10:11:09 pm

We changed ours out to a resonator two years ago and it has been great. It defiantly is a lot lighter. Our old muffler was huge and heavy, while the resonator is smaller and much lighter. Good luck!
Jeff

Re: Muffler to resonator?

Reply #5 – April 20, 2017, 05:19:22 pm

What brand of resonator does everyone suggest?

Re: Muffler to resonator?

Reply #6 – April 20, 2017, 05:25:31 pm

Most (including) me use Aero, search for other options on forum, lots of resonator threads

Re: Muffler to resonator?

Reply #7 – April 20, 2017, 05:33:09 pm

Used Aero on several coach's. Tried Jones Turbine on present coach, very similar to Aero but $50 cheaper.New Jones 5" TURBINE XL Truck Muffler Polished Stainless Steel 5050XL

Re: Muffler to resonator?

Reply #8 – April 20, 2017, 05:33:47 pm

It's an easy and inexpensive DIY job on a U300 but if you live in the mountains like we do, the Jake (if you have one) would be louder in our neighborhood. I think Andy installed one on his coach so he might be a good person to ask on the noise difference.

U300 Detroits have a 5" exhaust pipe so the following will fit. About $170 in galv steel, $225 in stainless. Google

Pierce

Re: Muffler to resonator?

Reply #9 – April 20, 2017, 05:40:56 pm

We started with an Aero and changed to a Magnaflow. Found the latter to be much quieter without any perceived change in other factors.

Re: Muffler to resonator?

Reply #10 – April 20, 2017, 10:21:16 pm

Will my cat 3208T go faster or get better mileage?

Re: Muffler to resonator?

Reply #11 – April 20, 2017, 10:29:50 pm

Not sure, but it will sound cooler

Re: Muffler to resonator?

Reply #12 – April 20, 2017, 10:37:24 pm

Quote from: Protech Racing – April 20, 2017, 10:21:16 pm

Will my cat 3208T go faster or get better mileage?

Gain 10 mpg and will need to watch for wheelspin when shifting into second.
Seriously, unless you are finally attuned to your coach, and keep good records of mileage. Probably not.

Re: Muffler to resonator?

Reply #13 – April 20, 2017, 10:41:03 pm

less back pressure - = either a tad better gas mileage, or a bit more power. But if you use the power - it will cost you gas - if you drive it the same way as before (in theory) you will have the same power at a slightly lower fuel burn.

For me, I noticed right away - much faster off the line - I suppose because turbo is spooling up against less resistance - that and the sound made it an easy decision for me - Again, search the forum threads - hundreds of posts out there on this topic - all from what to buy, how to install, etc.

Re: Muffler to resonator?

Reply #14 – April 20, 2017, 10:50:10 pm

I went from a rusted out muffler to a straight pipe with no resonator or muffler. Just five or so feet of pipe. Its loud outside but from the drivers position sounds wonderful. Didnt see any gains, but thats to be expected when the original pipe was no longer fully connected to the muffler.

Word of warning, if you drop the muffler on yourself, it hurts. Guess how I know. :/

This is not a good mod of you want to blend in. I always get a crowd of gawkers who want to hear all about my RV whenever I pull into a new campground. A common statement is "I knew this was something special when I heard it coming and saw those big chrome mirrors"

Re: Muffler to resonator?

Reply #15 – April 21, 2017, 12:19:28 am

Tim noticed the same things

Re: Muffler to resonator?

Reply #16 – April 21, 2017, 12:23:46 am

Quote"This is not a good mod of you want to blend in

??"

Did this years ago and put in a basic steel resonator and love everything about it. It does make a difference and an added one is less heat under bed.
A no brainer.
JohnH

Re: Muffler to resonator?

Reply #17 – April 21, 2017, 01:39:04 am

Faster spool up due to less back pressure equals less over-rich operating time (for mechanical injection engines) equals less pollution equals better fuel economy equals more hp generaly. Same goes for a BAHF air filter. Side effect on the exhaust may more noise. I have owned 2 vehicles that the WOT intake noise exceeded the the perceived exhaust noise.
BTW I'm pretty sure HD has a patent on how to convert gasoline to noise without the side effects of HP or performance.

Re: Muffler to resonator?

Reply #18 – April 21, 2017, 10:45:28 am

I changed to a 4" diameter Aero muffler several years ago, mainly so I would have more room in that area for something else (AC compressor units). The difference between the Aero resonator and muffler is length. Made of polished stainless steel which discolors as soon as it gets hot. Weighs less than a muffler. My experience is that it makes a little bit more noise at idle, but is about the same at speed. The turbo does most of the muffling. I cannot tell any difference in power or economy, but there may be a little bit of improvement. If you have a jake brake, the Aero may not be suitable.

Re: Muffler to resonator?

Reply #19 – April 21, 2017, 11:05:00 am

Jeff- my resonator is Donaldson, basic metal. I didn't need or want stainless under the coach. I like not having the heat in the bedroom after running and turbo spools up faster and a little more boost at top end also....

Re: Muffler to resonator?

Reply #20 – April 21, 2017, 12:27:33 pm

I agree with Michelle in reply #9 "We started with an Aero and changed to a Magnaflow. Found the latter to be much quieter"

I installed the Magnaflow because Brett W posted that it is favoured in Cat diesel websites he monitors because it is quieter.

I am not sure why most folks here seem to prefer the Aero, but do know from experience that the noise level is highest with pipe, then Aero resonator, then Aero muffler, then quietest with Magnaflow.

The Aero muffler (not resonator) has internal ports which Aero claims reduces back pressure using a venturi effect. I do not know if it actually works, but do know that it does change the sound.

Re: Muffler to resonator?

Reply #21 – April 21, 2017, 08:08:11 pm

What model Magnaflow? The website doesn't like 1993 Foretravel.

Re: Muffler to resonator?

Reply #22 – April 21, 2017, 10:13:05 pm

For the Detroit get the biggest one probably 5". Detroits flow a boatload of exhaust cfm because they are 2 stroke. At full load iirc it's around 2900 cfm so about 240 mph air out the pipe. use slash tip instead of straight tip at the outlet.

Re: Muffler to resonator?

Reply #23 – April 21, 2017, 10:19:24 pm

Quote from: Old phart phred – April 21, 2017, 10:13:05 pm

For the Detroit get the biggest one probably 5". Detroits flow a boatload of exhaust cfm because they are 2 stroke. At full load iirc it's around 2900 cfm so about 240 mph air out the pipe. use slash tip instead of straight tip at the outlet.

Have heard before that slash tip is better for flow, but wonder why?

Re: Muffler to resonator?

Reply #24 – April 21, 2017, 10:32:01 pm

Andy 2 is the only forum member I know who did this change on a coach just like yours (except the year: his is a 1992 but I think it has the identical muffler layout). Here's his post on it with pictures: Resonator install
It appears you need to select a resonator that is not too long if you do an install like his.

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