I was wondering of anyone has just replaced their stock muffler with a Magnaflow and kept the rest of the exhast system stock? How does it sound? Any performance gains?

 

Well it would be louder. Nobody has any proof (dyno sheets) that there is any performance gains.

 

I have, It sounds nice, but as for performance gains, I haven't felt or noticed any change.

 

I did it and it sounds great. As for performance, I can't say I noticed any. Go for it, doesn't cost that much.

 

Here is a link to my changeout to the Magnaflow. I am very happy with it to date. https://www.ford-trucks.com/forums/7...-no-drone.html

 

I wasn't that happy with the sound of just the muffler. Ended up going with a flowmaster until I have money to do the entire exhaust.

 

I have dyno tested a muffler only change vs a full catback and found the muffler only offered 2/3 the gain of the catback. Here are the test results below. I can't promise this will work in every case, with every brand, but if it was a good straight thru muffler, I suspect it would. What I liked is that the smaller pipes retained the low rpm velocity but he muffler eliminated much of the restriction at the upper end (as evidenced by the power gains). Anyway, if short of bucks, a good muffler brings you a good part of the way towards a catback... and you can run a nifty tip to dress it out. The only negative I noted was that with the muffler the system picked up a bit of a drone at a certain rpm.

BTW, these weren't Magnaflow mufflers or catbacks (they were Dynomax), but I suspect you'd get as good a result or better from a Magnaflow.

Test Data: 2005 Ford F-150 XL 4x4
5.4L 3V V8, automatic, 8,200 GVWR, 4.10:1 axle ratio

Performance Test Data

Condition 0-60(sec.) RWP (hp) RWT(lbs-ft)
(best/av.) (best/av.) (best/av.)

Stock 8.31/8.43 206.6/202.6 252.5/251.5
Muffler Only 8.10/8.15 215.6/215.1 276.4/266.9
Catback 7.89/7.91 224.8/222.6 283.7/278.3


Fuel Economy Test Data

Condition Steady 55 Steady 65 Steady 70 Overall
MPG MPG MPG Average MPG (1)

Stock 17.0 16.5 16.3 15.2
Muffler Only 17.2 16.7 16.5 15.7
Cat Back 17.3 16.7 16.6 15.7

Notes:
1) Mixed situations, approx. 35 percent city, 65 percent rural roads at 60 mph.

 

THAT IS EXACTLY WHAT I DID, BUT I DON'T KNOW THE MUFFLER PART NUMBER. THE MAGNAFLOW SOUNDS GREAT WHEN ON THE SKINNY PEDAL, AND THEN SOUNDS STOCK JUST EASY DRIVING. PERFORMANCE GAINS AREN'T GOING TO HAPPEN WITH EXHAUST WITHOUT FULL LENGTH EXHAUST(HEADERS, HI-FLOW CATS, ETC).

 

sort of on this subject...
I already have a dual cat-back system on my truck that was on when i bought it. Its had about a 20" glasspack muffler on it which was too loud. So i ordered a hushpower muffler for it but its still a little loud. Im thinking about swapping in a magnaflow so what do you guys think? someone said it sounded stock till you step on it. true?

 

Thanks guys!! Looks like I'll start looking for a magnaflow muffler then! I woudl love a whole cat back but with a family there is always something more important to spend $600 on. Any Ideas on a good resource for the muffler only? I can justify under $200 but not 6!

 

dude personally i wouldn't go with Magnaflow go with a real company. like Borla or Flow master, i will post U tube video of a real Flowmaster setup u will hear the difference. final thought. if your gonna do it. do it right

 

Go to any respectable muffler shop, that sells Magnaflow, and they will swap out the muffler and even put on a nice stainless steel tip for under $200.

 

Please post when you get that video up. I'd also be interested in hearing them.

Thanks

 

How is Borla, or Flowmaster any more a "real company" than Magnaflow? And how would he not be "doing it right" by picking anything other than the two you suggested?!?


The standard Flowmaster system is vastly inferior from a construction standpoint to the Magnaflow. The Flowmaster system is aluminized, where the Magnaflow is Stainless....asided from the material they're made from, the main difference between the two is Flowmaster's use of a chambered muffler design and Magnaflow use of a strait through set up.

..and if he's looking to eliminate "drone" and chambered muffler is going to be at the bottom of the list.

oh...and did I mention the Magnaflow has lifetime warranty vs. Magnaflow's 3-year warranty on these comparable systems?

The Borla too is a great system, that also boasts an all stainless steel construction....but costs several hundred more than the Magnaflow system.

So again...I ask you....how is Magnaflow not a "real company"?

 

I have the Mag on my 05 5.4, and it sounds great. Can't hear it at idle or doing 75 on the highway from inside the cab. With that, and the CAI, it almost sounds like an old muscle car with the 4bbl wide open when hitting passing gear at about 50. Dual Flows on my old '72 390 and they're louder than I would like. Some day I will replace both of them with the SS Mags. Much more refined sound.