Maintenance for muffler (?)

[GEN 3 SHO FAN]

Just wondering...

It's a good thing over time to change the mufflers for maintenance ? I know that some could have metal mesh in them that will fall apart with corrosion. Will they become cloggled over time ? I'm still running the originals mufflers. If yes, is there a method to restore them or to know how they are made inside ?

Thanks,

 

[rubydist]

The only reason to change mufflers for maintenance is when the outer shell rots away from rust. If they get clogged on the inside, you have way bigger problems than the muffler to worry about.

 

[luigisho]

Basically chambered with maybe some sound muffling fill. Agree with above no need for regular maintenance. Do you have a specific issue?

 

[GEN 3 SHO FAN]

No issue. As they are 25 years old, just wondering if they need some maintenance/replacement over time.

Thanks guys.

 

[stephen newberg]

The originals were very strongly constructed and of good materials. I suspect most people that have replaced theirs did so with the idea of changing the exhaust sound more than the need to do so due to failure of the factory muffler.

 

[luigisho]

Agree with Stephen above. However, I am impressed they haven't developed a rust issue up in Canada over 20 years. That's really good

 

[rubydist]

All the factory exhaust stuff is a pretty good variety of stainless steel, since the EPA requires that stuff last a fairly long time. I forget exactly, but I think its 5 years or 60k miles on all the emissions stuff. Anyway, its long enough that the use good materials so they tend not to rust out if cared for reasonably well (i.e. warmed up thoroughly etc.)

 

[GEN 3 SHO FAN]

Agree with Stephen above. However, I am impressed they haven't developed a rust issue up in Canada over 20 years. That's really good

More precisely, one muffler (driver side) developped an hole on the top because some salt fallen on top of it over time and with heat, create a small hole that we patched last year. other than that, no rust.

The car almost never saw the winter. And I must admit that some parts seems to have been paint (from factory ?) in black like mufflers and IAC valve also. The paint is falling apart after all this time but no rust. (I could take a photo of the paint on the mufflers.)

 

[RonPorter]

The mesh they referred to is not in the mufflers, it's the insides of the catalytic converters. Mufflers just **** out over time. If one of the cats get clogged, you will have other issues that you'll notice, with poor engine response.

 

[RonPorter]

Oh, how cute! This new software finds "blowe" (without the E) offensive!

 

[luigisho]

You ever think you'd see this in your lifetime? It wasn't that long ago that this would be laughed at as a concept.

 

[stephen newberg]

The problem is it is a truly mixed bag. Some things have gotten just hugely better in my lifetime. In ways I thought would never occur. Others have deteriorated to a point where a rational outside observer would say our society is going insane. In the end, you cannot let it get to you, though, or you will go insane. Better to just laugh at it as how strange life is.

smn

 

[luigisho]

Yeah I get your point. I'm just more of a reda$$ about certain freedoms. You folks up there have already put speech restrictions and compelled speech into the legal code. I'd like to tilt at windmills and stop that here.

 

[GEN 3 SHO FAN]

I don't even know that there is mesh in cats but some mufflers have too... From what I find, in the "straight through" design the mesh could block the flow if the internal part broke. The design of our factory mufflers is different, it's a "chambered" design and from what I see, there is no mesh in them but I could be wrong... (There is many internal setups for this kind.) They are better for noise cancelling but may cause exhaust back pressure but its another thread.

Example of straight through

https://www.etrailer.com/Performance-Mufflers/MagnaFlow/MF11219.html

Flowmaster ones too.

 

[RonPorter]

The whole discussion in years past was about cats breaking up. And either blocking flow, or getting sucked back up into the engine, causing catastrophic damage.

I have never heard of any muffler ever blocking flow. They just burn and/or rust out. Mesh holds the cat medium in place.

 

[GEN 3 SHO FAN]

Yes, I know that Ron and thank to you share your long experience with us. My own 3th cat was damaged and was blocking the exhaust flow a lot. (I was wondering for some time why I had a lot of warm air at the feet when driving until I found it.)

My thread is really on mufflers. I never found a picture on how stock SHO mufflers are made (inside). I had to make searches to understand that chambered ones, most of the time, don't have mesh. I put the results here for others...

 

[RonPorter]

Just a side issue, it's been proven that removing that silly 3rd cat loses power on a basically stock Gen 3.

Aside from that the choice of mufflers is a personal preference. But, from my experience, I've never heard a car that has not sounded great with Borla mufflers.

 

[rubydist]

Pretty much all stock Ford mufflers are conceptually like this Mustang example - the exhaust comes in the inlet tube, which extends part way through the enclosure. There are multiple chambers inside the enclosure, usually 3 like this example. In some cases the tube is open at the end, in others it has radial holes punched in it in the 2nd and 3rd chamber. The outlet tube is on the other side of the enclosure and also extends part way through the enclosure. Again, the end may be open like you see here, or there may be radial holes punched around the tube. The exhaust flow has to travel from the opening in the inlet tube to the openings of the outlet tube in order to flow out of the muffler. As it does that, the exhaust pulses are reflected off the various walls of the chambers which has the effect of reducing the sharp pulses and overall noise. The enclosure and chambers are tuned to provide a pleasant sound throughout the operating range of the engine.

As you can clearly see, the only thing that is going to go wrong is that the metal will rust.

 

[GEN 3 SHO FAN]

Just a side issue, it's been proven that removing that silly 3rd cat loses power on a basically stock Gen 3.

Ron, I will be curious to see these proofs if you can point at them. The only serious things I saw on this subject were dyno sheets saying the contrary on V8SHO.com...
This loss of power would be caused by the lack of backpressure or the bigger shape of exhaust at this place ?
Thanks.

 

[stephen newberg]

Ron might still remember were the dyno data is at. I remember if from long ago also, but not the site. I think there were a number of runs each under several configurations. ShoTimes FAQ, maybe. But the results pretty clearly established that deleting the 3rd cat had negative results in power output that were not insignificant. We are certainly talking a very long time ago, for when you go looking. '99 or '00 area.

smn