Resonator and muffler replacement

Topic: Resonator and muffler replacement (Read 12582 times) previous topic - next topic

Re: Resonator and muffler replacement

Reply #125 – June 12, 2012, 09:04:51 pm

Since 'everyone' was changing their original mufflers, we decided it would be a good upgrade for our coach. While we were in Santa Fe, we had an unexpected opportunity to have a truck mechanic friend who was an expert welder make the muffler change. But we had not purchased the Aero muffler and could not find one in the area, so we decided to use a locally available 'regular' resonator. When I went to the small muffler shop to pick up the resonator, I was very surprised how heavy the resonator was and to see that it was a straight perforated pipe, packed tight all around the center. When I commented how different his resonator was from the Aero we really wanted, the shop owner said he had a new Aero resonator muffler in his back room that he purchased over a year ago. He did not know his cost or what model the Aero was. But it turned out to be AT5050, which is probably the best one for our installation. So that is how we had a chance to compare the Aero to a resonator.

The Aero is unique design, much different from the standard resonator, even though it is called a resonator muffler. It has no packing, is quite light and is completely open. Just inside the inlet connection is an aerodynamic wing shaped concentric ring that directs exhaust around the open center pipe that is connected to the outlet connection. There are cuts on the center pipe that cause the directed exhaust to swirl out. The wing shape causes a slight drop in pressure on the inlet and the swirls help "pull" the exhaust from the turbo. Our Aero AT5050 is all stainless and is not expensive at $110 (Mufflers ).

We have driven a mountain pass since the change-over and feel that we are running 'easier', maybe with slightly lower temps. Changing our 2002 Jeep Grand tow car that we pulled around the country for 10 years, to a new 2012 Jeep Grand in January added about 1,000 pounds more weight to pull behind us. We felt the extra weight on our motorhome and now that we have the Aero for a month, we feel we are back to where we were with the 2002 Jeep. Sound is a little different, but not very noticeable.

Re: Resonator and muffler replacement

Reply #126 – June 13, 2012, 11:55:04 am

Hello,
when reinstalling the side panel and the trim strip, what caulking have you used? Are ther any easily removeable caulkings because I will be doing air bag replacement now and it may be another 6 mo. before I get to the muffler replacement and do not want to fight too hard getting the caulking off.
Thanks

Re: Resonator and muffler replacement

Reply #127 – June 13, 2012, 12:07:24 pm

If you know for sure you will be taking it off again inside 6 months I would go with a standard acrylic paintable filler just so you can at least seal it up. When you do the final removal I would use a good Polyurethane caulk.
John H

Re: Resonator and muffler replacement

Reply #128 – June 13, 2012, 12:40:31 pm

It seems to me that the resonator upgrade would be especially good for the '93 Cummins 5.9 mechanical engine. The 3030XL fits the exiting exhaust system and I wonder if there would be any advantage to moving to a larger exhaust fitting right at the resonator.

Anyone have any thoughts on this? After the solar panel project is completed I'm going to do a resonator, I think.

Craig

Re: Resonator and muffler replacement

Reply #129 – June 13, 2012, 04:45:38 pm

Quote from: John Haygarth – June 13, 2012, 12:07:24 pm

If you know for sure you will be taking it off again inside 6 months I would go with a standard acrylic paintable filler just so you can at least seal it up. When you do the final removal I would use a good Polyurethane caulk.
John H

John,
Thank you for the suggestion.
Rick

Re: Resonator and muffler replacement

Reply #130 – June 14, 2012, 12:38:26 am

Quote from: wa_desert_rat – June 13, 2012, 12:40:31 pm

I wonder if there would be any advantage to moving to a larger exhaust fitting right at the resonator.

Only if you change out the exhaust to 4" all the way from the turbo to the resonator. And then the bigger AT4040!

Re: Resonator and muffler replacement

Reply #131 – June 14, 2012, 12:48:47 am

Quote from: PatC – June 14, 2012, 12:38:26 am

Only if you change out the exhaust to 4" all the way from the turbo to the resonator. And then the bigger AT4040!

Not worth the trouble... we have a PacBrake in the way... I'll just get the 3030xl and work with that. Thanks Pat.

Craig

Re: Resonator and muffler replacement

Reply #132 – June 14, 2012, 01:07:46 pm

Can't hurt to go to the next diameter size and it probably will have a positive effect.

We decided to keep the short turbo pipe in place as it was in good condition and add a size increase transition at the end of the turbo pipe. If your exhaust pipe exits through a fiberglass hole, the hole will have to be increased for the additional inch increase.

Also costs for next size pipe, clamps, muffler are not much higher and there is probably lots of room to handle the increase, so why not do it. At least if you don't feel the handling is not a lot better, you will have known you did the best you could. And never have a doubt that one inch larger would have been better.

By the way, installing the Aero muffler on our coach did not need the removal of fiberglass side panel. There was plenty of room to work and side panel removal would not have made the job easier.

Re: Resonator and muffler replacement

Reply #133 – June 14, 2012, 06:45:43 pm

Has anybody tried NOT using a muffler or resonator?
How was the sound altered?

I thought I read that the Turbo was a approved muffling device. Maybe my recall on the subject is incorrect.

With the Small size of these mufflers and resonators I just wondered how much of a effect they even had on the sound level and tone.

Re: Resonator and muffler replacement

Reply #134 – June 14, 2012, 07:26:57 pm

Turbos cut the noise by about 50% but exact number is just a guess. I tried running a couple of 930s without the mufflers but they were way too loud for the street. A turbo diesel motorhome without any muffler would NOT be campground friendly.

Pierce

Re: Resonator and muffler replacement

Reply #135 – June 14, 2012, 07:40:54 pm

Barry, the reason for me removing the side panel was so I did not have to lie under the coach and work looking up. It was easy on my back to sit on a small stool and a plus for having it off was I could clean the cooling rad and engine and chassis very easily. Would have been messy lying under. I did it all on my own so with 2 or having a shop do it is a big difference IMHO.
John h

Re: Resonator and muffler replacement

Reply #136 – June 14, 2012, 08:14:27 pm

My experience using a 8V-92TA Detroit Diesel in a MCI motor home, with no muffler nor resonator, the turbo-ed engine noise was too harsh, installing the resonator took the harshness out of it, making for an acceptable level of exhaust noise.
Of course noise level/db is an opinion, some will never accept anything that is not stock, so folks have to do what makes them feel good.
For me, I prefer the free'r breathing engine, reduced heat build up and better performance using the resonator.
I also have been told that a muffler is not required on an engine with a turbo.
So again, do what makes you feel warm & fuzzy.
Cheers
Dave M

Re: Resonator and muffler replacement

Reply #137 – June 15, 2012, 02:00:40 pm

A foretravel U295 owner near my home tried a straight pipe on his 8.3 for a while but found it too noisy, so added an Aero 5050 resonator and is happy with it now. It seems to be louder to my ears than my M11 with a Magnaflow muffler. The Magnaflow has a deeper tone than the OEM, but is not louder to my ears.

Re: Resonator and muffler replacement

Reply #138 – June 15, 2012, 10:11:48 pm

John, I agree that for the short term, acrylic caulk is the way to go, urethane for the permanent fix.

As far as changing exhaust for the Cummins 5.9, both Cummins technical and Banks Technical told me that there is no advantage to increasing the exhaust flow since of the 5.9. The muffler used by Foretravel has way more flow that the 5.9 needs. That's what they said.

Re: Resonator and muffler replacement

Reply #139 – June 16, 2012, 06:34:32 pm

The exhaust housing driving the turbocharger is the pinch point in the exhaust. There is no benefit to going any larger than its cross sectional area downstream.

Re: Resonator and muffler replacement

Reply #140 – June 16, 2012, 08:20:46 pm

The more free flowing the exhaust system is the lower the back pressure will be. When back pressure is lessened after the turbo , less positive gas pressure before the turbo is required to spine the compressor blades. In the end to a point larger dia exhaust pipes and more free flowing mufflers reduce back pressure and should result in faster spooling turbochargers which produce broader torque curves and faster throttle response. Gam

Re: Resonator and muffler replacement

Reply #141 – June 16, 2012, 08:32:47 pm

gam, Right on, my coach picked up about 50 hp from just the change to the resonator, That is a guess on my part, how much hp increase does it take to be able to feel it ? Where my guess of 50 hp came from, now with that and the change to the ISM500 setup it does feel like 200 hp, (another guess) a big kick in the butt, very noticable in drivers seat, and feels real good.

Re: Resonator and muffler replacement

Reply #142 – June 16, 2012, 09:29:07 pm

Here is an excerpt and a link to the complete article from an engineer at Garrett Air Research, a big player in the world of turbos:

"Downstream of the turbine (aka the turboback exhaust), you want the least backpressure possible. No ifs, ands, or buts. Stick a Hoover on the tailpipe if you can. The general rule of "larger is better" (to the point of diminishing returns) of turboback exhausts is valid. Here, the idea is to minimize the pressure downstream of the turbine in order to make the most effective use of the pressure that is being generated upstream of the turbine. Remember, a turbine operates via a pressure ratio. For a given turbine inlet pressure, you will get the highest pressure ratio across the turbine when you have the lowest possible discharge pressure. This means the turbine is able to do the most amount of work possible (i.e. drive the compressor and make boost) with the available inlet pressure."

Here is the complete paper: Turbo Exhaust Theory

Pierce

Re: Resonator and muffler replacement

Reply #143 – June 16, 2012, 09:53:28 pm

RE: following Gam's point: free flowing mufflers reduce back pressure and should result in faster spooling turbochargers . . .

Aero claims include, creating a vacuum that cause Aero to be an improvement over no muffler at all:

"The Aero Turbine and Aero TurbineXL mufflers all use a patented Air-foil Technology By diverting slower moving outside air around the faster moving inside air, it creates a vortex that literally pulls the air off the head and out of the exhaust. The Aero turbine also spools up the turbo faster because of the vacuum effect created by the turbine, thereby further increasing the vehicles performance."

Re: Resonator and muffler replacement

Reply #144 – June 16, 2012, 10:33:27 pm

The Aero Turbine promises a lot and may work as advertised. On the other hand, the CEO could be Professor Harold Hill, class of '05 or a relative. Must be a non payola lab or major diesel magazine that has done some real world testing. Not a big believer in seat of the pants evaluation. Need a stopwatch to convince me.

Pierce

Re: Resonator and muffler replacement

Reply #145 – June 16, 2012, 10:45:34 pm

Quote from: wa_desert_rat – June 14, 2012, 12:48:47 am

Not worth the trouble... we have a PacBrake in the way... I'll just get the 3030xl and work with that. Thanks Pat.

Craig

Isn't your Pacbrake 4" with 3" reducers on each ends? Mine Pacbrake PRXB is.

Re: Resonator and muffler replacement

Reply #146 – June 16, 2012, 10:57:21 pm

Quote from: Pierce & Gaylie Stewart – June 16, 2012, 10:33:27 pm

The Aero Turbine promises a lot and may work as advertised. On the other hand, the CEO could be Professor Harold Hill, class of '05 or a relative. Must be a non payola lab or major diesel magazine that has done some real world testing. Not a big believer in seat of the pants evaluation. Need a stopwatch to convince me.

Pierce

Could be. But I do know that there are a heck of a lot of cult followed VW Jetta TDIs out there running around without mufflers, or in my case, with a reversed glass pac muffler which is basically a straight pipe. And many of them have been dyno'ed and found to have more power. And they are not noticeably louder.

Re: Resonator and muffler replacement

Reply #147 – June 16, 2012, 11:27:41 pm

Pat,

We manufactured a lot of turbo conversions for MBZ diesels and yes, I believe exactly what the engineer at Garrett says in his paper. We installed mufflers and exhaust pipes in as large diameter as possible according to customer's tastes. A straight through glass pack, resonator or any muffler that cuts back pressure to a minimum or off road with a straight pipe is the ticket. I just have trouble with "magic" muffler designs that claim to suck the exhaust out. To me the biggest possible inside diameter, shortest muffler/resonator works best with trade offs dealing with inside and outside noise levels necessary.

Pierce

Re: Resonator and muffler replacement

Reply #148 – June 17, 2012, 06:31:02 am

Joe Donnelly at the Turbo Diesel Register has done extensive testing of exhaust systems in Dodge pickups. He only saw measurable performance improvement above 3" dia. exhaust systems when engine output was pushed above 600 hp. Switching from muffler to resonator is lowering back pressure. Increasing pipe size likely not so much.

Re: Resonator and muffler replacement

Reply #149 – June 17, 2012, 07:40:30 am

Quote from: Pierce & Gaylie Stewart – June 16, 2012, 10:33:27 pm

The Aero Turbine promises a lot and may work as advertised. On the other hand, the CEO could be Professor Harold Hill, class of '05 or a relative. Must be a non payola lab or major diesel magazine that has done some real world testing. Not a big believer in seat of the pants evaluation. Need a stopwatch to convince me.

Pierce

No stop watch but my Silverleaf shows the difference. Much faster turbo spool up and I never saw Yellow on the gauge before. I see it now and I know I get two to three more lbs of boost. I also get better mileage. Now is it a vacuum produced, I do not know but it is lighter and more free in it flow than prior and it also sounds a bit better to me.

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