I have read that the mugen header improves the midrange. However, I was wondering if an exhaust system was needed as well. Can I just use the mugen header and benefit the same?
Thanks!

 

I have driven for over a year with basically just a Mugen header on an otherwise stock car. It does in fact improve daily driving and typical stoplight to stoplight runs. Not a _spectacular_ difference, but a good first step to other mods for sure. It also changes the exhaust note slightly(very slightly). I just recently added a PRM intake and the combo of the intake and the header feels great. I will receive my VAFC soon and that will allow me to maximize the benefit of these breathing mods. I have no idea when I will get a new exhaust, maybe next year some time. I still am leaning toward the Mugen exhaust, as I don't want the racket increased too much more than it is now.

 

The Mugen exhaust is only slightly louder than the stock set up and IMO only makes the car sound better. Its nowhere near as loud as many of the other aftermarket exhausts out there. The only downside to the exhuast is that it aint cheap.

 

You mean the only downside is that it is expensive....I don't consider the $1500 I spent on my Mugen exhaust "cheap"!

 

Correct. Sorry guys, brain fart.

 

King's website has a dyno graph that shows their headers / exhaust combo gains 15hp in the mid-range. I have the combo but I have not dyno mine.

Normal street driving is vastly improved with the combo. I can actually get the car moving from dead stop at 1.5k rpm, although it has help from the AEM CAI as well.