Aftermarket exahaust opinions help

[Tools R Us]

My advise is to post something like: “I like the sound of the Magnaflow and have had good luck with them.” Your arguments have zero technical merit.

Yeah...no, it's biased comments which are on every forum. "This one is the best nana" with no solid back up point. Such as you, bought a TRD FJ, and clearly love the TRD design, so it's kinda easy for me to assume you haven't listened to any other mufflers on your truck, NOT that I'm saying the TRD one is bad, it's one of the better ones.

It’s probably a good guess that the Toyota Racing Development unit was probably tuned, dyno matched to the rig. My guess is that it’s better matched to the power band of the motor than a generic muffler (probably designed for a small block chevy) slapped on at the local muffler shop. My problem with the TRD unit is that they are rock magnets, tend to get ripped off on the trail.

No, I'm not a rep for Magnaflow, but their muffler design is solid, and will outlast ANY chambered muffler design, and it sounds sweet while doing it too.

How much longer will it last? That’s a pretty good feat, a fiber packed muffler has tons of tiny passages between the fibers, unfortunately the exhaust isn't a clean place. The exhaust stream contains combustion byproducts (solids) these tend to clog small passages. All fiber mufflers that I have cut open have had at least some carbon in the fiber, most clogged up until it’s a solid mass. Chambered mufflers have large open areas between the plates, not at all likely to clog. About the only failure mode is a plate coming loose, when properly constructed that chance is slim.

My ‘84 Mini’s stock muffler has 200K miles on it and bet it still sounds very similar to it’s original sound. A good buddy drives a ‘97 Taco with 350K+ miles and it still sounds like a Taco. When you have 300K miles on the Magnaflow, get back to us about that, will out last anything bit!

And my point was, that with the design of the muffler (true-straight-shot) it clearly has more flow than chambered mufflers. … All tools r us, once again, just by LOOKING at a straight-shot design of the Magnaflow (and I'm sure there MUST be others with the design) you can tell how it would flow better.

No I can’t tell by looking. If you can see airflow there are a bunch of jobs where you can make big $$$. I’m not an engineer in the fluid dynamics field, but have done some amateur work, own some software and have ported bunches of heads. Lots of times what “looks” good doesn’t work. This is why professionals in the field use expensive things like flow benches, wind tunnels, modeling software, etc. If you can do it without all of that “stuff” your talents would be in big demand.

.... It is sourced originally from lava deposits found in volcanic rocks which are melted in a cupola furnace (sort of a man-made volcano). The lava rocks, taken right from volcanic areas that have experienced recent eruptions, are dumped into the giant furnace which heats to a couple thousand degrees. When the re-melted lava comes out of the furnace, it is spun, sort of like cotton candy and a special chemical treatment is added to give it water-repellant characteristics, then the whole spun material is bound together in a wool-like fleece. It basically becomes stone wool, which is ideal for thermal insulation, fire protection and acoustic control.
...

Good deal, more Magnaflow add copy. If you substituted silica (a type of rock) in the above process you would have fiberglass, plastic would result in plastic fiber, steel, steel fibers, that’s a common way of making inexpensive fibers.

I agree that rock wool (depending on the type of rock) has a higher melt temp when compared to fiberglass, but fiberglass softens at about 1700°C, if your exhaust is running that hot, the glass is going to be the least of your worries. Rock wool is slightly better noise absorbent, so more, thicker mat of fiberglass will net close to the same results. In the end all mat/pack type mufflers work the same, the noise waves are absorbed by the tiny air spaces between the fibers and these spaces are prone to clogging. The exhaust stream blows past, not through the mat, so there is no function to blow the carbon out of the mat.

The sound produced is subjective to the listener, has zero to do with motor performance. You prefer the sound of the Magnaflow and that’s great, others may not, I think they sound loud, raspy, annoying, have a nasty resonance at highway speed, etc. I would prefer silent, that isn’t achievable, so quiet as possible is good enough for me.

 

[NoHandleBars]

My advise is to post something like: “I like the sound of the Magnaflow and have had good luck with them.” Your arguments have zero technical merit.



It’s probably a good guess that the Toyota Racing Development unit was probably tuned, dyno matched to the rig. My guess is that it’s better matched to the power band of the motor than a generic muffler (probably designed for a small block chevy) slapped on at the local muffler shop. My problem with the TRD unit is that they are rock magnets, tend to get ripped off on the trail.



How much longer will it last? That’s a pretty good feat, a fiber packed muffler has tons of tiny passages between the fibers, unfortunately the exhaust isn't a clean place. The exhaust stream contains combustion byproducts (solids) these tend to clog small passages. All fiber mufflers that I have cut open have had at least some carbon in the fiber, most clogged up until it’s a solid mass. Chambered mufflers have large open areas between the plates, not at all likely to clog. About the only failure mode is a plate coming loose, when properly constructed that chance is slim.

My ‘84 Mini’s stock muffler has 200K miles on it and bet it still sounds very similar to it’s original sound. A good buddy drives a ‘97 Taco with 350K+ miles and it still sounds like a Taco. When you have 300K miles on the Magnaflow, get back to us about that, will out last anything bit!



No I can’t tell by looking. If you can see airflow there are a bunch of jobs where you can make big $$$. I’m not an engineer in the fluid dynamics field, but have done some amateur work, own some software and have ported bunches of heads. Lots of times what “looks” good doesn’t work. This is why professionals in the field use expensive things like flow benches, wind tunnels, modeling software, etc. If you can do it without all of that “stuff” your talents would be in big demand.



Good deal, more Magnaflow add copy. If you substituted silica (a type of rock) in the above process you would have fiberglass, plastic would result in plastic fiber, steel, steel fibers, that’s a common way of making inexpensive fibers.

I agree that rock wool (depending on the type of rock) has a higher melt temp when compared to fiberglass, but fiberglass softens at about 1700°C, if your exhaust is running that hot, the glass is going to be the least of your worries. Rock wool is slightly better noise absorbent, so more, thicker mat of fiberglass will net close to the same results. In the end all mat/pack type mufflers work the same, the noise waves are absorbed by the tiny air spaces between the fibers and these spaces are prone to clogging. The exhaust stream blows past, not through the mat, so there is no function to blow the carbon out of the mat.

The sound produced is subjective to the listener, has zero to do with motor performance. You prefer the sound of the Magnaflow and that’s great, others may not, I think they sound loud, raspy, annoying, have a nasty resonance at highway speed, etc. I would prefer silent, that isn’t achievable, so quiet as possible is good enough for me.

Do you, or HAVE you had the TRD muffler? It resonated louder than my Magnaflow in the cabin. But as I said, sounds very close to the notes of the Magnaflow. The Flowmaster overall was just terrible. It honestly sounded like the putt putt sound that the "ricers" in civics have around here, I couldn't stand it. A chambered muffler, if that is in fact what you're 84 had, degrades relatedly quickly, as most studies have shown, and of course my flow master on my 2000 Dodge showed. The moisture inside you're around winter time REALLY kills chamber mufflers from my experienced, studies prove that degradation speed of chambered being pretty "fast" too, however glass-packed, of course has the fastest (cherry bomb etc).

On the topic "of what looks good dosen't work" I'm not seeing how that applies to the muffler that I'm talking about in terms of "air flow". Chambered it relativly obvious that it will slow-down the flow, that is why the Delta 50, and so forth, have more chambers, the more chambers, the less noise. The Magnaflow has NO chambers, and goes straight through and on the way hits rock-wool on the sides of the round muffler that pings the sound off so while it's exiting it dampens it. I see absoultey NO way a chambered muffler could have a higher flow-rate than a straight-thru design. That's like having a bent pipe and saying the bent one can "somehow" have more flow than the straight one.

 

[knoll0351]

Why argue the point? There are people that get paid a whole lot of money to design these things to account for sound, vibration, air flow... and also Marketability. At this point it sounds as if your OPINION is exactly that and we have all read it...several times. It sounds as though others are offering advise as well, some based on opinion and some based on experiance others still based on statistics/facts.

As to flow that is why they have expensive machines to measure because it isn't as simple as straight vs bent, size of pipe and degree of bend also affects this equation as well as many other factors that I for one am no an expert on...but those that work in this field sure as heck should be.