OK, so all the posts are talking about the sound of the Roush...yes I want that too but I am also looking for an exhaust system that will give me some more towing power.

Has anyone done a before/after dyno on the Roush legal and off-road kit? How about an estimate of the gains?

Thanks in advance.

 

an exhaust change or muffler swap are not going to net you noticeable power gains, especially torque for towing (many cases you can actually lose that torque of you're not careful).

your best option to get power is tuning, preferably custom. for exhaust, get what sounds best to you, roush is a good option.

 

I'm betting it WILL gain you at least 1.5 mpg highway, maybe more.

I put on a borla SI/SO and didn't notice any increased hp but I gained 1.8 mpg immediately.

 

a single in single out will yield the best tq

 

Hey openclass, I had a conversation with you in another forum about the exhaust setups, and how you ran yours. I thought you settled on the 2.25 dual x'ed because you got the most gains out of it? Was your setup more for sound or performance? I understand you can gain hp and loose some tq, is that what happened with yours? would you have prefered to go si/so for better gains?

The reason I'm wondering is because after talking to you before I was all set to run a similar setup as you, I want the better sound with some gain though. If si/so is the best for this maybe I shouldn't run a setup similar to yours?

I happen to have a 2.5 si/so Hooker Aero Chamber muffler that I am now considering. I don't know how it would sound, but I had two on a s/c'ed v6 Grand Prix GTP and it sounded incredible. That and the Hooker flows something like 326 cfm, better than Maggie, Dynomax, Gibson and Flowmaster 2.5 mufflers. What do you think?

 

siso is better than si do for tq-you mentioned nothing about true duals with x pipe- which i feel is the ultimate exhaust setup which when done right yields torque but is the most expensive of thew three-phil

 

From what to what? Highway or town?

 

Cool, thanks for the info. I guess I'm not clear on "true" duals. Would a system like yours be true duals? I want to cut out the factory Y pipe, install the Maggie X-pipe and run dual 14" Maggie mufflers. On that note, does running a system with an X or an H pipe truely give better performance than dual out of each manifold (or header for that matter)? What is the purpose of the crossover pipe other than evening out the sound?

 

Highway mpg. These trucks are dogs for city mpg. I'm lucky if I get 13 city, so I generally just ignore it, I know it's gonna be bad.

I'm sure I gained some city mpg with the cat-back, but I don't bother calculating the city mpg.

I was surprised and very happy with the highway mpg gain though!

 

You want some real power? Are you willing to spend a load of cash? Buy some longtube headers, preferably dynatech, two high flow cats, an x pipe, a 14’’ magnaflow DIDO muffler, take the truck to the muffler man and have him run true duals, that being one pipe ran from each header back that remains independent from the other, that meaning that you have two seperate pipes running the entire way from the headers all the way out the tips. To top it off, buy an AF1 CAI. The power I gained from the headers alone was 30 hp and 30 ft lbs of torque, and the CAI adds up to another 17 hp. That is not factoring in what the rest of the exhaust setup will yield you. BTW, you cannot get a kit for true duals. You’re going to have to get it custom done at the exhaust shop.

 

Ive been bouncing all different options off the wall, and havent committed yet. I have an 05 screw, 5.4, roush cai, troyer underdrive pullies, and have decided on the dtech long tube headers, but should I go with the ones for the lightning / harley into a dido muffler and have an exhaust shop run it out back for the best gains ? what dia. tubing ? to keep the low end torque. Otherwise I had made my mind up on the roush offroad system, and the dtechs with the y pipe . Which way to go. I prefer to do things once, and keep in mind future power upgrades. Any help ? J.B.

 

Oh yeah , Ive got an Edge also which I run On stage 3 all the time.

 

i'd run x-pipe-2-siso mufflers and 2.25" tubing for maximum tq-i'd get a custom dyno tune for the edge runninh lt's-better yet get a troyer tune -phil

 

2.5'' piping worked fine for me... also, bear in mind that all of that flow that you are gaining w/ longtubes will be choked significantly by using a y pipe. chances are that you would save money by having the exhaust shop custom make a true dual setup than buying an exhaust kit. i highly recommend custom tuning for this sort of application.

 

I have an exhaust guy that Ive used in the past who does super sweet work. Both runs back have to be on the passenger side if Im correct do to the placement of the gas tank. I thought a DIDO might have the same effect as an H pipe . the pipes would be running side by side anyway. Im still looking for a shop close by that could do the dyno runs and custom tune. Im in northern Ma. /So. NH. I was hoping I could find someone comfortable doing it using my Edge.