Magnaflow or Flowmaster

[Wild one]

Magnaflow vs. Flowmaster, Who Makes the Best Muffler?

Is a Magnaflow or a Flowmaster muffler the best? We dig deep into the question and get some help from an Engine Masters $40 Muffler Dyno Test.

www.motortrend.com

 

[HEMIMANN]

Magnaflow vs. Flowmaster, Who Makes the Best Muffler?

Is a Magnaflow or a Flowmaster muffler the best? We dig deep into the question and get some help from an Engine Masters $40 Muffler Dyno Test.

www.motortrend.com

Excellent summary of engine exhaust physics, thanks for posting.

My 6.4 Hemi on the 3/4 ton truck has a single, massive exhaust pipe with the school bus muffler. My research led me to do no upgrades. LT headers wrapped was just too much loot and retrofitting for +10% torque. The tow tuner for $600 satisfied me.

Messing with the muffler butterfly valve introduces MDS exhaust drone, so I didn't remove it, leaving MDS on when not towing to prevent Hemi tick. The OEM muffler is so large I fear a Magnaflow might increase back pressure instead of reduce it. Also, the resonator prevents mid rpm drone so I left that alone too.

If I had a half ton truck with dual exhaust I'd for sure add the X crossover pipes. Interestingly, my Harley came with it because the 45 degrees cylinders produce an unbalanced exhaust pulse.

 

[Penmaker]

The OEM muffler is so large I fear a Magnaflow might increase back pressure instead of reduce it.

Stock mufflers are very restrictive. Look up videos on YT showing stock mufflers cut apart and you'll see what I mean. Magnaflow is basically a straight through muffler. Flowmaster has a little more restriction than Magnaflow but it's still a lot less restrictive than stock. I have Magnaflow on my 5.7. I just like the sound of Magnaflow over Flowmaster.

 

[HEMIMANN]

The OEM muffler is so large I fear a Magnaflow might increase back pressure instead of reduce it.

Stock mufflers are very restrictive. Look up videos on YT showing stock mufflers cut apart and you'll see what I mean. Magnaflow is basically a straight through muffler. Flowmaster has a little more restriction than Magnaflow but it's still a lot less restrictive than stock. I have Magnaflow on my 5.7. I just like the sound of Magnaflow over Flowmaster.

Not true for heavy duty trucks. Engine Masters saw little difference from muffler changes - only a straight pipe showed meaningful power increase. The crossover pipe helps to even the cylinder scavaging from the twin pulses from each cylinder bank. That's a real increase. So are long tube headers for the same reason.

 

[Burn2k12Ram]

Really if you are talking about the same kind of muffler between the two and even other brands the difference performance wise is negligible. Really for the most part there is two kinds of mufflers. The chambered(as shown in the article) and open style/glass pack. Any muffler that is a chambered kind is going to be more restrictive than an open style. Really you can think of a chambered muffler as a resonator as it does inhibit the sound even a little bit depending on size compared to going just straight pipe or open style muffler. Like the article explains you want power gains get those headers done. With my truck only replacing the massive stock chambered muffler with a Flowmaster Flow FX exactly the one in the article and did not get the sound I wanted. For the most part you are going to have some kind of drone with a chambered muffler(if you remove the lame stock resonator) and to me had a little better sound than stock but still WAY too quiet. I then changed out with a dynomax open style race bullet and that was exactly what I was looking for. Awesome sound and quiet when idle or just cruising. When you step on it, it's all eyes on you and no drone like the flowmaster had.

I by no means am an expert with exhaust but is how it was explained to me by an exhaust shop and with all else equal the open style muffler(dynomax) was music to MY ears compared to the flowmaster flow fx.

 

[HEMIMANN]

Yep - mufflers are really just about the sound you like. Engine Masters multiple test with all sorts of mufflers on the same engine on a dyno proved they don't change much for power output.

You can search for that episode on Motortrend TV. For me, I was more interested in how the old-time Chrysler 440 kicked their 426 Hemi's a$$ up to 5,000 rpm where the siamese valve breathing kicked in.

That's why Hemi is nothing but marketing for truck applications. We've opined about a double OHC modern V8 from them for some time. Ain't happenin' - the Euro-mafia is shoving a Beemer engine down USA's throat. Oh, well.

 

[ccmano]

Excellent summary of engine exhaust physics, thanks for posting.

My 6.4 Hemi on the 3/4 ton truck has a single, massive exhaust pipe with the school bus muffler. My research led me to do no upgrades. LT headers wrapped was just too much loot and retrofitting for +10% torque. The tow tuner for $600 satisfied me.

Apologies for hi-jacking the thread. Tell me more about the "Tow tuner for $600"
H

 

[HEMIMANN]

Apologies for hi-jacking the thread. Tell me more about the "Tow tuner for $600"
H

That's just the Diablosport Edge Pulse add-on ECM tuner. You take the 8 tunes pre-installed instead a single custom tune to your desires.

It's half the cost of a custom, and good enough for my towing extra power. You can turn MDS on and off also and it stays that way. When you turn off with the gear shifter, it resets to after every shutoff.

 

[ccmano]

Thanks, I'm trying to get a little more torque out of my 5.7 for towing. It does a reasonable job with the 7.5k lbs Travel trailer we pull through the mountains here on the west coast. I've got a Diablo Sport I3 with a canned 87oct tune but I think there's more to gain. I have an email in to Hemifever to get their recommendations. To my knowledge the Edge Pulse is not available for 2014's.
H

 

[Wild one]

Yep - mufflers are really just about the sound you like. Engine Masters multiple test with all sorts of mufflers on the same engine on a dyno proved they don't change much for power output.

You can search for that episode on Motortrend TV. For me, I was more interested in how the old-time Chrysler 440 kicked their 426 Hemi's a$$ up to 5,000 rpm where the siamese valve breathing kicked in.

That's why Hemi is nothing but marketing for truck applications. We've opined about a double OHC modern V8 from them for some time. Ain't happenin' - the Euro-mafia is shoving a Beemer engine down USA's throat. Oh, well.

The 426 Gen 2 hemi's combustion chamber is differant then the Gen 3's combustion chamber.Comparing the Gen 2 to the Gen 3 is akin to comparing apples to oranges.

 

[HEMIMANN]

The 426 Gen 2 hemi's combustion chamber is differant then the Gen 3's combustion chamber.Comparing the Gen 2 to the Gen 3 is akin to comparing apples to oranges.

Yeah I know 440 is an ancient engine. It was a demo of cubes versus flow.

Cross flow didn't take off till 5k rpm was the point.

With a modern head an DOHC, that's the V8 I'd want. Breathing open from low rpm for a non turbo engine.
Not sure why Cummins went SOHC for the ISX15, since it's highly turbocharged with variable vanes. I never did get a good answer on that one.

 

[canadiankodiak700]

just like the company slogan...

PEOPLE WHO KNOW USE MAGNAFLOW.