How was your exhaust ran? I'm guessing that it was dumped? I've got the orig. 40 series, 3" in, 2 1/2 dual out, ran all the way out the back to the bumper with 18" slash cut 3 1/2" tips. There is a drone, but not to where it is unbearable, or at least I think not. The road noise seems to cancel most of it out....or at least the radio will...

 

[QUOTE=ictf150]I had the 18" Magnaflow SIDO muffler installed on my 2004 F150 5.4L this weekend with dual pipes exiting straight out the back/rolled chrome tips - and was a bit surprised at how quiet the setup is overall - even WOT. I do like how quiet it is at idle, and the deep tone is nice..so my question is this:


The best way is to take the truck back t the muffler shop, have them drop the muffler, listen to it without any muffle, then have them hold each type of muffler up to the pipe that you would consider. You will know in a metter of 15 minutes what you want installed.

 

I've got the SIDO orig. 40 flowmaster and it sounds great. I'm on my 4th mustang right now, (67' convertible w/ 289 hi po, 70' mach I w/ 351C, 68' coupe w/ 302 and 87' LX w/ 351W ) and except for the 87', which has true dual 40 flowmasters, I like the sound of my F150's 4.6 just as good as any of them.

 

Just got back from having the Flowmaster 40 installed, I noticed a bit more aggressive sound at startup and accelerating, but I guess I was hoping for more sound at idle and a bit louder.

Does a muffler typically get louder after the initial 'break in' period? If it doesn't I may want to try something different yet - or maybe I'm trying to get a sound that doesn't exist with a stock 5.4L setup.

 

magnaflow mufflers break in do to being packed with sound deadening materials- flows don't as they are baffled-pk

 

The flowmaster line will "break in" after a short period of driving. REally depends on lots of factors, like how you drive it, how much you drive it, etc. Mine got a real good immediate break in with a 1000 mile roundtrip that started 3 hours after installation.

WaWa, I think the 50 series may well be more in line for you. The 50 Delta shoud reduce interior resonance by about 40%. If thats still not enough, consider the 50SUV line. The 50 isn't nearly as aggressive at idle, but still has good throaty tone under load. The 50SUV is about 50-60% less on the interior resonance. Also, when I noticed the slight drone in mine, I realized the solution was simply to beef up the stereo and that eliminated the drone.

 

flowmaster also sells resonators that you install after the muff to take away the incab noise. My buddy had one on a flowmaster system on his 5.3L GMC. It wasn't loud in the cab but sounded good outside. And no a flowmaster won't "brek in over time" The muffler is all metal, with bafels, no packing to burn out or "Break in".

 

The cabin noise to me is barely noticeable with the flowmaster 40 - with the stereo at a lower volume I couldn't even hear it crusing on the highway - the magnaflow had a similar 'drone' at 1800 - 2000 rpm for me.

Would replacing the stock cats with high flows make a difference in overall sound ?

 

I've heard that it will...and yes the Flowmasters will break in, they get louder over time...mine did.

 

can i get in on the bet too? i have been around shows/strips since i was 5...hmmmm 37 years now...you were born ? 1990?

i run SIDO mag/flow out behind rear tires/45 degree angle..not overly loud,till i step on it ...no drone