I have a 2002 F150 5.4 and I'm thinking of having a shop install a single 3" catback with a magnaflow muffler and an 18" X 3.5" tip out behind the rear tire.
I have no idea what this will sound like. I don't want it to be very loud, just a little more growl. Any comments?

 

Which size MangaFlow muffler ?

The larger the body of the muffler, the less the noise.

If you go with the larger body ones, ( 5" x 11" by 30" long is what I seem to recall at the moment ) then this is slightly louder the stock, with a bit more growl.

If you go 5x8x30 then this would be more so louder ( the size of the Bassani's that I have on at the moment ).

Just a few thoughts on the topic.

All the research I did was on the SS ones only.

 

The multi-cat setup makes any muffler much quieter than you would think. Ask the shop if they have several versions and if they can tack weld the muffler in and let you start the vehicle and hear it before they permanently weld it in. If you want mild sound, I agree with SSCULLY, select a larger muffler body.

 

Well I had the shop order a muffler. I went with an XL- 5 X 8 X 18. The exhaust guy said there wouldn't be that much difference than the 24". He thought I would be happy with it. Hope he's right!

 

5" x 8" x 18" in a SI/SO 3" ???
You needed to get the oval larger, as well as the length to lower the levels. The Muffler shop guy is right, the length alone won't make that much difference.

Ouch....that is going to be loud !!

I have 2; SI/SO 2.5" 5"x8"x30" Bassani mufflers on my duals, and it is NASCAR Truck series ready. Above 3,000 RPM don't even try to be talking on the cell phone. Running it to 5,200 RPM, it is brutal.

If you take a look at ChiDiver's posts, Larry just yanked, I think, the same size muffler off ( In Bassani ) , as it was too loud.

 

I took off a Bassani 3" si/so 5 x 9.5 x 24" that droned terribly on the highway. After a couple of resonator tips and a lot of looking I wound up with a Magnaflow 14591 5 x 11 x 30 3" si/so SS case. Just a little louder than stock with a nice tone to it. Even with a 4.10 gear I can hold a conversation or hear the radio on the highway.

NO RESONATING IN CAB

 

This muffler has the same dimensions but 6" shorter than what comes on Magnaflows popular catback 3" si/so system, #15609. There's alot of guys on here that seem to love it. They said it's not that loud.
Maybe mine won't be that bad.

 

I just had a Flowmaster put on today on my 2004 F150 XLT 5.4L. Sounds great. SI/DO Flowmaster 430402 and Stainless tips on the back.

$300 plus tax installed.

 

I had a 5X8X18" Magnaflow installed, only I had them just keep my factory 2.5" pipe in place. They simply cut out the factory muffler and added a short piece of pipe with the magnaflow. It sound great. Not very loud but has a nice growl when you get on it. You should be happy.

 

Thats good to here Sean, makes me feel better.

 

Valid point made here, I am using the dump in front of the pass side rear wheel, so maybe where you dump it has as much to do with the noise level as the size of the muffler.

I have a SCrew, and with the rear pass die window down it is loud, specifically when up against a concrete bridge wall ( bouncing the sound off the wall ).

I don't recall exactly where ChiDiver had his, I thought in the same place ???

 

Mine exits in the stock location behind the r/r wheel.

 

I had my new exhaust installed today. 3" single with a stainless 5X8X18" Magnaflow #12259 muffler and a 3.5X12" SS tip. It's not loud at all. Just a quiet throaty tone. Total cost was $170.
I was having visions of it sounding like my nephews loud chevy with dual flowmaster 40's.

 

Yes you got what you wanted...good stuff...I wonder if the extra sound at highway speed is a problem in the cab ?? I use to get a headache driving in a friends truck...I like the sound but fear never getting away from it at times on a long drive??? I have hearing aids now as well...Is this system harder on your motor in anyway ?? for back pressure I mean ??

 

I hardly notice any more sound at highway speeds than stock.

This is from the Magnaflow website.
"As a general rule, you can enlarge the pipe diameter of your OEM exhaust system by 1/4 to 1/2-inch to increase your horsepower. However, any additional increase in pipe diameter is likely to decrease your performance; specifically, low end torque."