Magnaflow versus Flowmaster ~ Showdown on the Dyno

The ones that have more than one in and one out collar have more than one pipe... like this.



Some Borla mufflers even have multiple perforated cores with single collars...





Mufflers are a totally fascinating technology.

You'll likely be right. Other tests have been done before and Magnaflow had the edge over Flowmaster because of it's simple direst straight through design. So many people have bad mouthed Flowmasters for so long the same things get repeated over and over.

So I'm curious to find out for myself exactly how well a resonant design stacks up to a straight through design under the same conditions on the dyno.


Greg

 

@tooter please continue with this.. It seems to be an actually very interesting comparison! Someone can finally solve it!

 

The do-nothings will always try to piss on the do-somethings.

It's my pleasure, Dawg...
The two muffler designs are so completely different... it will be fun putting them head to head just to see what happens.


Greg

 

Sub'd, looking forward to the results. I went with the flowmaster since it appears to be a more robust design. Lots of trucks around here only get a few months of good sound out of magnaflows before the deadening material goes to shit.

I'm going to guess the flow master makes better low end torque (because these little engines need some back pressure) and the magnaflow gains a bit of high end power due to the angled tube design. If that's the case I'll be very happy, since on a truck I'd rafter have power start further down low than add a bit up high.

Btw haters gonna hate. They're probably sore from some sort of divorce/sodomy/etc that threatens there tiny existence and big ego's.

 

I will, regardless of what anyone says.
But this question will most likely only be resolved for a certain narrow set of conditions, as both Magnaflow and Flowmaster make a lot of different mufflers from mild to wild. I just picked one of each, and chose the mildest sounding mainstream models.

Most all testing is of race mufflers on high performance engines because that's logically where the most interest in results is. There's a lot of money in competition motorsports.

In contrast, my interest is just in how these two different designs perform with a stock low performance engine under normal everyday driving conditions.


Greg

 

Yes. My Yaris has had one for two years now and it's louder, however not at all unpleasant. I really like the Magnaflow sound.

I agree. Everything I do on my truck is to enhance the low end pull. I couldn't care less about top end performance.

A lot of resonance technology has been designed into the Flowmasters, especially the 50 Series Delta Flow which is a relatively new model with the most sophisticated tuning features. A robot builds their mufflers and precisely locates and welds the internal components to within .004" accuracy so as to cancel out just the right frequencies.


Greg

 

Yeah, I did.

 

The two mufflers to be tested are the 22 inch long 5" x 11" oval stainless Magnaflow #12586 2.5" center inlet/offset outlet...



...and the 17 inch long 4" x 10" oval stainless Flowmaster #842452 Series 50 Delta Flow 2.25" center inlet/ offset outlet...



I already did a dyno run with the stock muffler and exhaust, and will be able to compare both the Magnaflow and the Flowmaster to it. My engine has a few other bolt on mods:

Injen intake
tooter intake manifold spacer
LCE long tube header

...but the block is internally stock with no tuning. All of the runs will be done with the same mods, the same regular 87 octane pump gas, and no other changes except the muffler as the only variable in each run.

The Flowmaster obviously appears to be the more restrictive of the two, but that isn't the end of the story.

Low rpm (1,000 rpm to 3,000 rpm) torque is maximized by retaining exhaust gas velocity. And at low rpms, the exhaust system is underutilized. So while an open free flowing exhaust system enhances high rpm performance, it exchanges it for a loss of low rpm torque.


Greg

 

Found this sound comparison between the two

 

its not a official tw thread without a little butt hurt and shenanigans.

 

It's ok, Boone.
Piss all you want.

Greg

 

Of course. It's like AM radio.
There will always be some static.

It's off to Harry's Dyno shop tomorrow for the Magnaflow runs.








Greg

 

I read through this article dyno testing a bunch of mufflers on a 370 horsepower Mustang.

http://www.mustangandfords.com/part...ler-comparison-test/muffler-dyno-numbers.html

While it didn't specify which models of mufflers were tested...

...throughout the entire tested range (2750 rpm to 6,500 rpm) Magnaflow logged average gains of 3 hp and 3 ftlbs of torque over the Flowmaster. Again, a very slight edge goes to Magnaflow over Flowmaster.

But remember that's just a difference of 3 out of 370 total which is very small when expressed as a percentage of the total.

That's less than one percent.

I believe that difference would be imperceptible.

 

Bingo.

For me, it's about the tone, and especially on a 4-banger, the quieter the better.
I went with a MF on my '94 and I was happy with it.
I hate the "pissed off go-kart" sound that the Honda kiddies seem to love, and I spend too much time on the road to tolerate a drone.

Those db numbers are helpful... at 70mph, just the wind noise in my cab is 82db.

 

The old "rule of thumb" is that if you don't gain better than 5/10 percent you can't perceive the increase. I put two numbers there because it seems like a lot of guys with a ton of bolt on's say 5. I have bolt on's, but I believe realistically in the 10 percent figure. Most guys with exhaust perceive the "rumble" sound as making things faster, yet when you run a quarter mile with stock system on an aftermarket exhaust results are mixed at best.

Also all dyno's have a margin of error between 3-5%, so the 1% in the article is pretty much saying there the same.

What I'd be really curious the more I think about it is the performance compared to stock. Something tells me on the Tacoma stock will beat both for low end torque. I know I felt like I lost gas mileage because of my exhaust before I went to force aspiration. After supercharging I think the exhaust made a huge difference in my setup.

Lastly, I double checked with the local muffler shop. They only sell magnaflow at his shop due to a supply contract and he replaces most of the magnaflow mufflers he installs after 2 years due to packing wear.

 

With mods that logged dyno improvements of 15% more horsepower and 20% more torque over stock, the difference is perceptible. But after a while I get used to the gains and it "feels" normal again, and then I want to try out other things to see if I can make more gains.

We're definitely subjective beings, and sound is a good part of the fun of driving.

Yes. That's an important point.

Muffler manufacturers aren't stupid. They do their own research and development, and dyno testing. It's truly amazing that so many different designs can end up being grouped together so tightly!

Another good point.
So far all of my gains have been with the stock exhaust. So there is also another ancillary test going on that I'm really curious about.

While the Magnaflow muffler that's going to be dyno tested today is more free flowing than the stock muffler...

...the rest of the exhaust pipe is now slightly smaller than the stock pipe diameter. I did this in an effort to retain exhaust gas velocity so as to keep the low end torque. I don't yet know how well this worked out, but the dyno will tell the tale.

So not only will the mufflers be compared to each other with exactly the same exhaust system, that same mandrel bent exhaust system will be compared to the stock system. I'm almost more curious about this than the mufflers themselves, as the difference between them will likely be small. The other constants for all of the tests are the LCE long tube header and the Injen intake. Out of everything else I've done, that header still remains the best mod that made the most improvement on the dyno.

Yes. Opening up the exhaust on a normally aspirated engine reduces low rpm torque because it slows exhaust gas velocity. But you get more sound so it subjectively ~feels~ more powerful.

After two years, the one in my car is louder than it was new. But it's such a nice sound I don't mind.


Greg

 

Who's underside truck picture is that, in your post #41?

 

Certainly nothing I own!
It's just a google picture that turned from a search for "multicore mufflers". I do a lot of google picture searches just to see all of the different muffler and exhaust designs.


Greg

 

Did the dyno run today.

And all the Magnaflow muffler produced was..... sound!


Here's the chart:



The previous run was 4th gear so the speed limiter cut it off at 4,700 rpms. I did this run also in 4th gear so as to be done in as identical conditions as possible. Basically +2hp +2tq... which is a very slight difference between the stock exhaust and the Magnaflow muffler. We did get the run to start recording at only 1,100 rpm because I especially wanted to see what the off idle torque was.

Run 007 was done with:

Injen intake
tooter intake manifold spacer
LCE long tube header
stock muffler and stock tailpipe


Run 010 was done with:

Injen intake
tooter intake manifold spacer
LCE long tube header
22" long 5"X11" oval Magnaflow muffler and 2.25" mandrel bent tailpipe

Harry suggested that I do some kind of tuning to richen up the mixture as it's running really lean at WOT.

The Flowmaster gets installed this coming Wednesday. I'll run around a bit to get the ECU to relearn. Then it'll get tested again and I'll post the results.

Greg