I started this as a new thread so the original muffler mod thread would not get completely sidetracked.
The Aero looks to be a nice improvement. My 8v71 muffler has a 5" inlet, which I assume to be standard, and a 4" outlet, which doesn't matter. The only problem I see is that the current muffler has both inlet and outlet on the same (rear) end, so this would require changing the location of the exhaust discharge, Which would put it around the back of the rear tires. It looks to be within the skill set of a good muffler shop.
Is there any downside to making the switch? I guess Scott, for one, would know since he has done it. Anyone else?
Just wanted to add something else. The muffler/welding shop I sometimes use recommended buying a similar product, Magnaflow 12774. The specs on both are almost exactly the same. He claims that he has seen Aeros develop cracks. Anyone have any experience with Magnaflow?
I use a Magnaflow 14774 muffler. 5" in 5" out straight through. It is about 30" long and 8" dia. It is loud on a 2 stroke but no back pressure. It is silent on a 4 stroke Cummins.
It looks like the difference between the 12774 and the 14774 is that the former is satin finish and the latter is polished.
I have had my Aero stainless for 10 years now and no problems,, it's still polished as new.. I have never heard the cracking statement,, I think he wants a sale.>>>Dan
Seangie put the Aero Muffler on his Eagle back in May, 2016, and he had good luck with it.
Okay, for all of the muffler comparison fans I wanted to report my research results.
The Areo AT5050XL is made of 304 grade stainless while the Magnaflow 12774 is made of 409 grade stainless, which has a lower chromium content. The Magnaflow 14774, as Bill G. has, is made of a grade of stainless that is somewhere in between the two. Further, the Maganflow unit is a straight thru muffler and can be mounted in either direction. The Aero unit is not straight thru and has a dedicated inlet and outlet. They claim that their design evacuates exhaust faster than a straight thru pipe. The Areo also has a built in resonator, which is supposed to modulate the droning a bit.
I ordered the Aero through my muffler shop. It really makes no difference to him which I want. His price for either is the same as online. He makes his money off the installation, which will be in the range of $125. I am mainly interested in anything that will lower the engine temps. Of course, any extra power or fuel mileage would be nice too.
Lin,, study the entire exhaust system and determine is some other changes can be made to reduce restrictions in the system.. I was able to remove two 90 degree elbows by redirecting the flow and then added the aero resonator and got a substantial improvement of my Cummins 8.3..>>>Dan
BTW, who has slid under their bus lately to look at, let alone polish, their SS muffler?
Just sayin'
Jim: Agreed that I do not really care about the appearance of the muffler. It may be debatable whether more chromium is better or not. Aside from appearance, more chromium adds more rust-free life though. I'm not sure if it is more brittle and don't know if that makes any difference.
Utah: The exhaust pipe drops right out of the engine with one el to the muffler, so there is nothing to do there. I do not really think there is any abnormal restriction, but if increasing exhaust evacuation reduces some heat, it seems worth it to me.
To clarify,, I remove two 90 els and replaced that angle with one 45 el to counter the problem you have,,every little bit helps.. Also I heat wrapped from the turbo to the muffler to increase flow and reduce heating the bedroom.>>>Dan
Heat sleeves are a little more convenient and waaaay easier than wrapping.
http://shop.grpipes.com/templates/product.aspx?ProductGuid=HS-24&GroupGuid=33
After 33 years as an aviation mechanic/inspector,,I have wrapped quite a number of exhaust systems and prefer it.>>>Dan
It does work but I just never got the hang of it nor a fancy to the music ;).
Lin, when i got my bus the inlet and outlet were both on the same end and my exhaust pipe came out under the back corner of the bumper. Couldn't see it in the mirror. Looked like it could get ripped off if i went thru a deep enough dip. When i had to get a new muffler i got a Donaldson with inlet on one end and outlet on the other. put a 90 on it and had it come out right behind the tire. Liked it because then i could see what color smoke, if any. was coming out. Because the body angles down toward the tire a little from the bumper, i flattened the end of the 90 just a little to give more clearance. :)
Airplane engine exhausts are not usually subjected to salt spray unless they are operated at low altitude over the ocean. The salt can make a huge difference, retaining water and causing rapid corrosion. I've seen wrapped headers rust through completely in one year's time to the point where they were unrepairable. Salt water boat exhausts might be a better comparison.
Stainless comes in many grades. Most have both Chrome and Nickel alloyed in along with other elements. Either may predominate. Typically Nickel stainless will be non-magnetic and chromium stainless will be magnetic but it depends mainly on the Nickel content. Lower grades can and do rust. To know the properties of a particular grade of stainless you have to look it up. Then you can do a proper comparison.
Jim
The 304 grade stainless used by Aero is not magnetic, and the 409 used for the Magnaflow 12774 is magnetic due to its lower chromium content. Research online says that 409 is the most common grade used in exhausts. It can develop surface rust but that is generally inconsequential. Interestingly enough, the 409 steel is supposed to be pre-heated before welding.
Only downside:
It's loud.
But not nearly as obnoxious as a straight pipe.
The end.
Quote from: Scott & Heather on September 30, 2019, 06:54:37 PMOnly downside: It's loud. ...
Which brings up a basic question in my mind -- what's (usually) the easiest engine to quiet, a 2-stroke or 4-stroke? Which is louder with a straight pipe?
Thanks, Bruce
Turbo engines are the easiest 2 strokes or 4 strokes Lin's 8v71 NA will be a loud sucker with AERO or a Magaflow and he will not like it.Bruce both are about the same noise level with straight pipes
I looked at a Eagle for a friend that had straight pipes on a 8V71 NA, and I found it to be irritating, not enjoyably loud. In a campground setting you would not make any friends. The Aero Muffler would be better, but without the turbo, it would not increase your popularity. :o
A turbo will lower the sound level quite abit,, the resonator will take out the sharp crack.. Overall a mellow sound and not irritating.. I have had folks mention when I passed them they knew I was there but not obnoxious.>>>Dan ( My exhaust exits the right rear corner)
Well Clifford, You may be right. I did not consider that the Turbo was quieter. I guess I'll find out soon enough.
We have installed the Areo muffler, and I want to post the results in case anyone else is researching such a switch. I have not yet gone on a trip that would help determine whether there is any fuel, heat, or mileage benefits, but I can report on the sound difference. I downloaded a sound measurement application for my phone and recorded before and after readings. I measured from each corner outside the bus and also back, middle, and front inside. For the most part, there was a 3 decibel difference at each location except the front to outside corners. For some reason, they were about 10 Db higher after the install. This seems kind of strange since the driver's seat had only a 3 Db increase. The back corners measured from about 10 feet away went from 73.5 Db to 76.5 Db. The inside back (bedroom) was 68 Db and increased to 70.5 Db. The middle of the bus (kitchen) went from 60 to 64. The driver's seat went from 60 to 63.
These numbers were all at idle. Although it might not seem like much, it was definitely a lot louder. The really noticeable difference though was when accelerating. I did seem that there was quite a roar at times. Once up to a cruising speed though, it did not seem to be very loud at all from where I was sitting though. I think that leaving a campground at 4 AM would get a bit of attention. Definitely better to air up with my auxiliary compressor. I probably would like it to be quieter for my neighbors, and if there are no mechanical benefits, this would not be a good project. If it helps keep heat down and contributes a little extra power and fuel mileage, I would consider it a good trade-off though.
The old muffler was a 36 inch long cylinder with an approximately 15 inch diameter. My guess is that it weighed at least 80 pounds. The new one is only about 7 inches diameter, 30 inches long, and weighs around 15 pounds.
Wait till you engage the Jakes it will rattle your teeth
I did use the Jakes. Sounds like trucks I have heard, but it is okay from the driver's seat. I may change my MCI badge to Tesla so people will think that sound comes from somewhere else.
A 3db level increase equals double the sound level.
Jim
Could be. I do not completely understand the science. It seems to say online that a 3db increase is twice the energy, but that that does not translate to the perceived sound level as being twice as loud. Anyway, it is certainly very noticeably louder.