How do these two mufflers stack up against each other?
Flowmaster vs. Magnaflow
Does either one have a distinct advantage over the other? I’m trying to find something for my 04 Screw that will sound good and maybe gain a couple of horses too.

 

I had a Magnaflow installed today on my 2004 Screw. The muffler shop had both Magnaflow and Flowmaster in stock. I went with the Magnaflow because I liked the way it is straight through, no chambers at all. They cut the stock muffler off and put the new one on with the addition of about two feet of pipe. (30 min.)Looks like a killer job, real clean; right around $100. bucks out the door. It definitely sounds strong, like a V8 should.

 

jpdadeo -

Which Magnaflow model did you go with? What are its dimensions, do you remember? Thanks!

 

It was the Universal Aluminized Steel Muffler 4” by 9” oval 14” long. It was the Offset/Offset style with 2.5” pipe. I went with the steel because of the price and you can’t see it anyway unless you climb under the truck.

Check out the pics

https://www.f150online.com/galleries...6167-92667.jpg

https://www.f150online.com/galleries...6167-92666.jpg

https://www.f150online.com/galleries...6167-92665.jpg

 

each muffler has it's own merits. I have heard the magnaflow mufflers "pop back" on deceleration which I do not like.

I currently have a Flowmaster 3" si/do 2.25" on my o2 SC fx4 5.4. the seat o the pants meter thinks i gave up a few ponies on the low end, but is sounds great! although a little on the loud side.

On my previous 00 SC ORP 5.4 I had a gibson 3" si/do 2.25". the seat o the pants meter thinks that we retained (if not gained) low end. The muffler was louder than stock but quieter than a Flowmaster until you hooked up the trailer! yeeehaw...with a trailer it was louder than a Flowmaster.

When my current flowmaster wears out or rusts through, I am going back to the Gibson.

I hope you find this information (or rant) useful.

 

From my two F-150s I would have to say Magnaflow. My 2001 had a Flowmaster. I hated it. It was loud at idle, droned at highway speeds (1500-2300 RPM) and sounded ok at WOT. My 2003 has a Magnaflow and I like it. It has a healthy rumble at idle, is quiet going down the road, and roars when you mash on the loud pedal. I won't make horsepower/torque claims baised on my butt-o-meter because I know that it is not correctly calibrated, but from what I have read here on the boards the Magnaflow makes good power mid to high RPMs and is one of the only aftermarket systems that does not lose torque at low RPMs.

Joe

 

I got a little bit of both. I like the flowmaster low end sound from the 40 series and it's been one of my favorite mods on my truck. The magna flow tips probably don't do much for sound. but they look awesome!

 

I got a little bit of both. I like the flowmaster low end sound from the 40 series and it's been one of my favorite mods on my truck. The magna flow tips probably don't do much for sound. but they look awesome!

 

Magnaflow will last longer w/o rusting.