How effective is this muffler design?

RarlyL8 · RarlyL8's Garage

How does this design work? The path is straight through with a perferated core. What use is the lopsided packing? Is it an effective sound deadener?

Craig 930 RS · 02-13-2005, 06:45 PM

I'd need to see the inside path/tube sizing etc but it looks similar in concept to a Magnaflow. These have a good sound with zero baffling -

RarlyL8 · RarlyL8's Garage

It is a Magnaflow. Tubing size is 2.5" straight through.
Just looks odd having asymetrical packing material. I don't see the point.

350HP930 · 02-13-2005, 06:59 PM

Without the traditional packaging it would look like a glass pack which would not pass the visual test in many states.

RarlyL8 · RarlyL8's Garage

Visual test? HA! My ENTIRE CAR can't pass a visual test. I'm sorry the area you live makes you think of such things. I gotta meet you next time I'm in Tampa visiting my brother so I can see your beast-in-progress.

The muffler does look like a glorified glass pack or "cherry bomb". I'm just trying to understand the design. If you have all the packing on one side of the muffler how effective is it and if it is, how does it function as a sound deadener? It seems to me that a straight through design would allow a very large % of the noise to travel straight through the muffler as easily as the path itself.
Anybody use one like this? Pretty loud?

350HP930 · 02-13-2005, 07:30 PM

Florida is completely lax when it comes to emissions testing, but a noisy car with obviously non stock exhaust system can get an expensive ticket from any cop that feels like writing one.

I assume there are other states with similiar harassment laws, not to mention emission states like california where appearances are just as important as function, if not moreso.

Craig 930 RS · 02-13-2005, 07:43 PM

The offset *is* weird.
Go for a Flowmaster - fits right in there on the SC and will give ya a buzz from 2200 to 3200 (resonance). ;-)

randywebb · 02-13-2005, 07:55 PM

Teh offset may not be what it appears. The gas flow path might from a U inside... have to chew it open to see. If so, that would give a longer path length in a shorter space.

RoninLB · 02-13-2005, 08:19 PM

fwiw, Monty is a balance tube design afaik.

RarlyL8 · RarlyL8's Garage

The path is straight through. I have seen it with my own eyes, just don't understand how it would work. Looks to me like a "cherry bomb" shape would be much smaller and just as (in)effective.

I don't want a loud car, that's why I'm looking at different designs. Glad to hear Florida hasn't gone all smog Natzi on us yet.

Craig 930 RS · 02-14-2005, 08:55 AM

I can see how it would work - the increased absorption of the large packing area would absorb more noise, while retaining the classic 'muffler' shape -

IROC · IROC's Garage

A few years ago, I needed a "quick and dirty" exhaust on my car just to tied me over until I installed my headers. I had a shop in town (Clanton Muffler here in Madison - highly recommended) make me up an exhaust that was nothing more than a glasspack (straight-thru, "cherry bomb" style) that attached directly to the single outlet of my then factory heat exchangers.

Believe it or not, it wasn't that bad as far as providing a functional muffler. I even did a track event with it. A little louder than stock. Crappy "note", but it worked.

I have yet to hear one of these "Flowmaster" exhausts that I thought sounded very good, but YMMV.

"Visual test"...ha ha..whew...that's a good one. :>)

Mike

KobaltBlau · 02-14-2005, 09:23 AM

magnaflows (perf. tube) flow much better than flowmasters (baffle) ... FWIW. Maybe less of an issue on an NA car (which Rarly's isn't. It's hard to make an aftermarket exhaust for these flat 6es without an annoying resonance.

Craig 930 RS · 02-14-2005, 09:25 AM

Back-to-back dynojet 248C tests show the Flowmaster has about 5 hp on the Magnaflow.

One of those 'don't know why it works but it does' kind of things.

randywebb · 02-14-2005, 10:54 AM

"don't understand how it would work"

Ok, since it's straight thru - here is one idea. IF the pressure waves are not completely absorbed by the fill and thus hit the walls, the assymetry will cause them to hit the walls at different times. That means they will not add up and resonate as much (most likely -- excuding harmonics). Just an idea. One would have to do some testing and modeling to find out for sure. Also, this allows the resonant chamber to be larger. And -- if it was "designed" by "some dude," rather than an engineer experienced in wave phenomena, you can toss that idea out the window. It could just be a whimsey, or an attempt to fit a given space, or who knows...

KobaltBlau · 02-14-2005, 10:58 AM

Quote:

Originally posted by Craig911
Back-to-back dynojet 248C tests show the Flowmaster has about 5 hp on the Magnaflow.

One of those 'don't know why it works but it does' kind of things.

Ok, my experience to the contrary was based on front-engined turbo cars. so obviously YMMV for a specific engine config.

Craig 930 RS · 02-14-2005, 12:12 PM

Yeah its one of those things where for a specific application the Flowmaster seems to show that it is the best muffler for HP output for the larger flat 6 Porsche engines.

This was tested with B&B headers btw.

donstevens · donstevens's Garage

Tha packing helps to absorb the burbles and pops. This config would be very loud at WOT which could be cool.

Don

RarlyL8 · RarlyL8's Garage

My (turbo) application requires a straight through design for maximum HP. I've looked at just about every muffler type out there to find one that will do the best job muffling in the space provided while not robbing power. Not an easy task.
I stumbled upon the above configuration by accident. A coworker of mine bought a new Dodge Hemi truck that came stock with the above tail pipe muffler. I snatched the muffler when she swapped it out for an aftermarket exhaust. It is 3" OD and straight through. Must work or they wouldn't waist the money on materials. I just have a hard time seeing exactly how it can work well.

Hey IROC, I have been to Clanton's place. My buddy with the high strung Carrera had his exhaust done there. I plan to have him do mine once I make a muffler decision. On another note, the local PCA is trying to get some DE practice and training in at the Auto-X Park on Saturdays. Interested?

Rob Channell · 02-14-2005, 06:01 PM

RarlyL8,

In my own limited understanding a muffler works like an expansion chamber. The gases come in fast under a high pressure and are allowed to expand and lose some energy before exiting the muffler. A gun silencer works in a similar fashion by allowing the gases to expand and lose energy in a series of expansion chambers before releasing them(not that I know anything about that, either).
The gases will expand to fill whatever shape the muffler has until the pressure is equal thoughout the muffler. This is a dynamic process that will change the average internal pressure over time due to engine speed and throttle (air throughput), and in your case, boost as well.
Your turbo is already quieting down the exhaust a little bit. I would think it wouldn't take much of a muffler at all (if any) to make it good enough. I'd be tempted to try it. You could probably get Clanton's to install it for $60 or less since you already have the muffler.

And count me in for DE practice. Will that be at the old airport?

BTW, we will be having a Trackaholics meeting this Thursday 17th at West End Grill at 11:15am. That's in Huntsville, Alabama for anyone else that wants to join us.