I entered this site knowing absolutely nothing, learned some things, and heard many more things contradicting what I thought I had learned concerning a true dual exhaust setup. Right now, I'm confused as hell... I thought I wanted true duals w/ a 2.5'' X Pipe, high flow cats, a new muffler(s) and 18'' in tips 3.5'' wide slashed, all stainless steel and magnaflow. I've heard all sorts of **** including that true duals are a waste of money, they actually hurt performance, and cause problems w/ the computer, that an x pipe will not fit on a 4x4 due to the transfer case, (my truck is an 03 FX4 5.4L) etc... Was this an exhaust shop's nice way of saying they didn't want to mess with the job, or is there any truth to this? I've heard all sorts of "evidence" to back up claims on both sides, and am aware that exhaust shops can get in a lot of troube for messing with emissions control, but I still am confused as hell...

 

Everybody I've talked to, said true duals are a waste unless you have a forced induction motor.

 

so then, what would be the best setup to go with then, performance-wise?

 

The biggest problem with duals is the pipes are to large compared to a 2 1/2" or 3" single. 2 1/2" duals are like a 4" single exhaust which is way to large for even a 300HP engine. Also you really need to have a h-pipe or x-pipe of some kind to equalize the exhaust (or maybe a single in/dual out). I wouldn't go any larger than 2 1/4 duals myself.

Here is a formulated chart per flywheel hp and size of pipe.

http://www.angelfire.com/my/fan/Exhaust_Pipe_Size.htm

 

i also saw a 2.25 in x pipe how well would what work, with same size piping?

 

If you can find a complete 2.25" kit with some form of crossover tube that will fit a 4X4 then go for it if that's what you really want. Your pushing 300 flywheel hp in stock form so with a couple mods including exhaust you not to far off with your pipe size. I like single exhaust because they can make the same power with less weight although duals usually look better. I do have a dual Maganflow 2 1/2" on my 5.0 GT with H/C/I but they came with duals from the factory.

 

my towing was vaslty improved with my 2.25 x piped dual system-phil

 

interesting, i think i will get this done after all...

 

mini - I have an '04 that I had true duals w/ 'H' pipe put on over a year ago. I have Flowmaster 40 series with Magnaflow 12' 15 degree tips. I love the sound. If I lost any low end torque, I haven't felt it yet. I don't regret this mod at all. Go for it!

 

03 FX4 SuperCab: 2 1/4 true dual, dual Magnaflow Cats, custom X-pipe, dual Flow 40's, exit L-style. The whole system was custom done from the motor back by a member of the FTW NJ Chapter.

Looks great, sounds awesome, and I even gained hp/tq.