I'm considering replacing the factery on my 04 f-150 5.4 with two options.

Daul exhaust from the mainifolds back, mount mulfers side by side, not flat, run pipes out the right, in frot of rear tire, or run two pipes over the diff. and exit behind the right rear tire.

Just replace the mufler with a performance one, keep all factery pipes..

Any thoughts?

 

cyclone,

I am looking into exhaust on my '04 too. I am considering a super 40 muffler SI/DO in the rear. I know I have read some articles about how it's good on these trucks to run 3" pipe if you're going with a SI/SO setup, but I'm not sure about the size to run on these trucks for a SI/DO or a DI/DO setup. Also, if you run true duals you'll need to do an X or H pipe to balance the flow, not sure what size the pipe should be though. I have heard from flowmaster on the phone that running true duals on this truck will create a big loss in power, but I have posted threads in several spots of this forum and nobody has ever really answered my question about that. I'm skeptical of that setup, but I wanted it just for the sound and have 2 flowmasters on there. But at the same time, I've read posts on here where people with 1 flowmaster 40 says it is loud and sounds great, and then there have been other posts on here where people say it is not loud enough. I like it loud enough to hear while you're driving, and to have a really mean growl to it. In my town, I still don't anyone with any kind of exhaust setup on their new f150, so I have nothing to listen to to judge by.

 

I want to cut out the y-pipe and go from thier with duals. I have had dual ex on cars with out a X or H pipe and they ran good. The transfer case takes up a lot of room under the f-150 The left ex. of the mainfold is longer and is bent to go in front of the transfer case, than booth the right-left go into a y pipe...

 

true duals will give u the most overall power but if u wanna keep some low end power. but i have it dualed right after the cab sounds good the interior drone isnt as bad if their right under the cab wrather then behind.. more sound insulating its under the cab then from behind. . but if u have the 5.4l then dual 2.5" pipe is what u want for the 4.6L use 2.25" pipe.

 

that's the same sit up I want to do, Thank you FasterF150