-
Need new muffler
Yesterday we developed a large hole in our muffler. Looks like it corroded from the inside out, looked fine externally when I checked it a few days ago.
The sound is great, much deeper than normal, not too obnoxious. It does get a bit loud with the Jake brakes on. I’m debating on whether to fix it when we get home (1,200 mi) or stop by Mira Loma service center to have it replaced. Any issue with holding off replacing the muffler on the road? It still seems structurally sound, just has an 8 inch hole in it.
Thanks, Gerald
-
12 Replies
-
Don’t think it will hurt you mechanically but the sound outside might make some think you are hauling a NASCAR driver. I also have a 99. I will probably have the same issue at some point.
-
Last year had muffler with hole in bottom put JB weld over hole until I could get one, when I replaced it , it was all rusted out on top where you could not see it, you can get to clamp from back of motor and long extension on ratchet , and the rest from under the back . Got round tip from truck shop still goes out side looks good tooo.
-
Has anybody tried a stainless steel diesel performance exhaust rather than the OEM muffler? Here is a 4 inch version
http://www.ebay.com/itm/Aero-Turbine-Performance-Exhaust-AT4040XL-Muffler-/221022866986
-
A friend of mine has the 5″ version on his Eagle with
the 12.7 Series 60. I’ve been standing behind his bus when he accelerates
from a stop and I don’t think it’s excessively loud. I haven’t heard it with the Jakes on, I suspect that could be loud. If you have a retarder then you
won’t have to deal with that. I think you’ll need the 5 inch.
I’m eventually going to put one on mine.
Ken
-
Ken, aside from the sound, has your friend experienced any change in performance and/or economy?
-
He installed it when he did the engine swap so really nothing to compare it
to. I used a 12.7 muffler on mine so it maybe a little restrictive. I think the
stock muffler is about $1200 dollars compared to about $150 for the stainless Aero.That’s another motivator for me.
It’s also much lighter than the stock one. I know it’ll sound faster with the Aero, but I don’t want too much fast. I prefer
quite.Ken
-
I looked up the price of the regular muffler (540045) at Prevost parts. It is $640. Not exactly a bargain. There might also be a stainless steel version for more $s. The Aero would require an elbow and supports to be fabricated. Definitely something to think about.
-
The last muffler I replaced I bought from Prevost. But knowing how they charge for some generic products such as brake chambers and Norgren valves I believe when the time comes to replace the muffler I might just bring the one being replaced to my local truck parts guys to see if they can match it.
I’m not comfortable getting creative and buying one that requires some mods, not because the effort to make it fit might be cumbersome, but because in some cases the muffler might contribute to how the engine performs and I would be afraid one that is more restrictive or more open might be harmful. Need to do some research.
-
Don’t be afraid of having an open/ free flow muffler on a 12.7 Detroit. It will be louder, but it will run better. We have done several hundred semi tractors with a free flowing muffler set-up for the 12.7’s and have had very positive results, but you need to know the CFM specs on any muffler you choose. John is absolutely right (as usual) that a more restrictive muffler will adversely effect engine performance. Most factory systems are pretty restrictive because they need to meet dba standards, but the after-market has more latitude. Jake brakes are louder too. Normally, mufflers that have the inlet on the side and out the end or out the other side are not as efficient as mufflers like that little torpedo pictured above. I’m sure that there is very little baffling inside, so it will flow more freely. Noise is reduced in an exhaust system by changing the direction of the flow. A muffler with baffles forces the flow in different directions and therefore reduces the dba levels, but it also increases the resistance. Additionally, try to avoid really sharp angles in the system, as that too, increases resistance. I know that is very difficult to do in the back of a coach. I firmly believe, the last item designed on any motor vehicle is the exhaust system. It ends up being the poor little sister that has to work around everything else.
-
Well, I drove the bus 1500 miles with the large hole in the muffler. It sounds ‘good’ particularly when using the Jake but I did not notice any performance or mileage improvement. Max turbo psi was still around 26 at 1900rpm and 100% load and fuel consumption remained around 6.95 mpg towing the Jeep.
Given that somewhat disappointing result I’ll probably just replace with the OEM muffler.
Gerald
-
Sounds like you should not replace at all!
-
Gerald,
Did you notice any decrease in the pyrometer temps with the large hole? One of the signs of a free flowing system is lower exhaust temps. Maybe your hole is in a place that still has several internal baffles that are restricting the flow, but does let it make more noise-especiallty the Jake brake. It does sound cool, but you are 45′ ahead of the noise.
Log in to reply.