I have the flowmaster 17226 on my '03 and I just installed the magnaflow 15749 on my friend's '98. The only thing I notice is a difference in tone. They both sound good. I don't notice any performance difference, but I did notice a price difference. Its all personal preference if you ask me.

 

Everyone talks about the Magnaflow mufflers being too quiet, but those are the same people using the big mufflers. I had an 18" Magnaflow on my 2v 5.4 and it sounded good but was too quiet. I recently swapped it for an 11" Magnaflow and this was just what I was looking for. Very similar sound, considerably louder, but still no drone at cruising speeds. Sounds and performs way better than a Slowmaster, IMO.

 

dynomax bullet

 

Not on the list.

 

Guys like Fish claim they lost a lot of torque from a Flowmaster muffler and switched to a Magnaflow then gained noticeable HP. I don't c noticeable gains from a muffler.

 

With my last truck with a 5.4 I lost torque on the low end with the Flowmaster. I could spin the tires with the stock muffler and after I had the Flowmaster installed I could not . My new truck with a 5.4 I went with the Magnaflow and I did not lose or gain any torque .

 

If you want it to sound awesome, then get the Flowmaster. Even IF it does lose 10 ft/lbs of torque in the low end, your butt-dyno wouldn't be able to tell. Just because a truck can spin the tires one day doesn't mean it can do it the next, there are several factors involved.

 

If you want to lose power with great sound then get the Flowmaster period! Sorry but my butt dyno could feel the power lose !

 

I didn't lose any power You can keep your extra 10 ft/lbs of torque. I'll take my sweet sound any day.

 

You lost more then I gained .
Do the math .

 

Says you. Have you had your truck dyno'd?

Without data, yours is just another opinion.

 

So is yours...... .

I had both and know first hand that I lost torque with Flowmaster .

Call Troyer and he can give you all the data you want, you lost torque .

 

Fish, dude I can still spin my tires after my Flow install on my 03 5.4. I gotta call you on that one. A muffler aint all that serious. A Flowmaster is not robbing power like that and a Magnaflow is not generating much xtra HP especially on the low end.

 

You could have crappy tires........


I could spin my tires by mashing the pedal down (no power breaking) on stock muffler.....replaced with a Flowmaster and could not spin the tires for the 2 years I had it (same tires). I only added the Flowmaster in place of stock muffler. I did no other mods.

I loved the sound of Flowmaster......but lost to much low end.

 

Mine spins the tires just as much as it used to, even though I upsized. I had the exhaust on before I got the tires btw, and it still spun them just as much as it did before the exhaust.