So i bought a '04 f150 screw from a dealer used last month. i absolutely love the truck. When my fiance and i bought it, i saw that it had magnaflow dual tips out the back. once it started, it sounded low and mean. truck sounds great going down the road. anyway, after searching this site and people talking about the different mufflers they had, i went out ot my truck to see what kind of muffler i had on it. so i get underneath and look around, then look some more, and come to find out, there is no muffler. its a stock y-pipe, going into a 3" I-pipe, then it has another Y-pipe that is 2.5 out the back. So im thinking, cool, no muffler, i can live with that, but what im most confused about is the fact that i thought with running no muffler, it would be a lot louder. Im assuming that becasue it has the 4 cats that those are keeping it quiet still? any input would be great, trying to learn as much as i can about the new truck. the last truck i had was a '98, so this a totally new game to me now. Thanks!

 

yep those 4 cats are toning it down. i've heard before, and i'm seeing it now for myself, that a smaller sized muffler will make it sounds better and maybe even a tad louder than none at all if you get the right one. i don't think i've ever heard straight pipes from the cats back before though.

 

i cut mine before the y-pipe and ran true duals lightning style no mufflers and love the sound just got to get a x-pipe to help scavenge the low end power back.

 

thank you both for the quick response. it is lacking a little on the low end. i feel as though the '98 f150 had more torque down low, but the '04 def flies up top, which honestly, when driving on the highway, its nice to have the ability to pass whenever i want, and it makes it easier to merge into traffic.

second question now, would the GOTSmod that is used on the newer trucks (i know it has a different name, just cant think of it) would this help with the torque at all, or is it just for higher rpm gains? Thanks!

 

not sure on the gots mod although its popular and alot cheaper than going my route with the s&b intake but yea deffinitly feel it on the upper end thats why i'm having to install an x-pipe to get the bottom back. i'm not sure on yours since you've got the origina y and single back to duals what would help on yours. look for darrenws6 he seems to be the one on exhaust( not knocking on anyother member) but he deffinitly knows exhaust on these trucks

 

Thank Ford's engineering department for your truck being so quiet. Swap the cats out for a pair of 94106's, run true duals with an H/X-pipe and it won't be quiet ever again.

 

Is your '04 a new body style or the heritage? Also, is it a 4.6 or 5.4? I thought the NBS trucks only came with 2 cats? Also, the size of the pipe could be making it quieter than you would think without mufflers. Are you looking to go louder? Or did you start this thread just wondering why our trucks are so quiet? I'd like to hear a video of this setup.

Oh, and welcome to f150online

EDIT: nevermind the question about it being old or new body style...no 04 screws were made in the heritage body style.

 

06 and up only came with 2 cats

 

ok...i guess i had heard that before now that ithink of it.

 

Your 4 OEM cats are ofcoarse the main thing keeping it quiet ( 04 - 05 trucks are the quietest with the 4 large cats and 32" OEM muffler ) and the fact that its a single exhaust without a muffler, and its probably crush bent piping which nucks it down to quieter also.

 

Its the 5.4, new body style. Really not looking to get louder. ita loud enough for people to hear me, but quiet enough that i dont wake neighbors in the early morning. I really was just posting to try and understand why its so dang quiet, lol. Thanks for the welcome!

The piping that is run under the truck seems to be different than the OEM piping. i think its mandrel bent, but id have to get under the truck to tell. But the I pipe is def a 3 inch pipe, and its all welded together.

Ill see if i can remember to take some pics of it tonight, as well as a video.

 

OEM exhaust is full mandrel bent too, but the intermediate pipe for OEM is 2.5 up until 2009 so that is definitely different. These Fords are just real quiet also. Small price to pay for having the best built, toughest, longest lasting, and hardest working truck.

 

Yea, im def ok with it not being crazy loud. The truck is a daily driver, so being able to talk on the phone, or talk to others in the truck is a must. So the fact that its loud enough to sound good, and be heard coming down the road, but quiet enough to still be "civil", IMHO is the best of both worlds.

I was able to get some pics last night, but never had a chance to load them on the computer. going to do that tonight when i get home.

 

My Magnaflow muffler showed up last night so i cut the factory muffler off my 06 x-cab w/5.4. I then realized that i did not want to " rig" my exhaust or have a shop use cheap crush bent piping ( already called 3 muffler shops), so i ordered a SISO mangaflow cat-back this morning...Anyway, right now i have my exhaust dumped under the x-cab.I also thought it would be louder. Some might like the sound but i do not, and hopefully the cat-back will arrive saturday.

 

its going to sound different for a couple reasons. first you have the stock size I-pipe, its also dumped under the truck, which means its going to resonate like crazy, plus i have dual tips out the back, which is also going to sound different than if it was run single pipe out the side.