extremely quiet, other than for the looks I dont like them. I'd venture to say they dont do much either cause the Roush I dyno'd with only put down 230-240 rwhp (I dont member if he was stage I or II) but it was an 03
yeah, it seems to be pretty hard to get the side exit exhaust to increase performance- I would definately say due to the extreme bend to send it to the side....I think the Steeda side exhaust flows pretty well, and Spintech sounds awesome... so theres some other ideas. (unless steeda is borla too??)
I think I remember reading on fnsweet.com that some people get the Roush exhaust and then toss the Roush mufflers and weld in Spintechs. Also, I think Roush uses Magnaflow mufflers not Borla. I could be wrong.
I have the exhaust and it is magnaflow mufflers and My horsepower is 265 at the wheels with the mods listed below and the are quiet. I am wanting to get some louder mufflers and put them in there myself so it will be a little bit louder.
also quiet... BUT the enhanced sound ones are pretty good sounding... they are shorter mufflers and sound MUCH better...
however another option is the Spintech system that is custom made to fit the Roush sideskirts and tips. for the spintech side exhaust I CAN GUARANTEE that it sounds so much better than any magnaflow mufflers... also it sounds like 100X better than 40 flows and it looks awesome as well...
here's a pic of my car before the IRS swap:
i also had the spintech system on and that thing sounded amazing with everything else stock... i can only imagine what it would sound with a prochamber or a good h-pipe