i have a itr motor with a compression around 11:1, ctr cams, vafc, N1 exhuast, 4.785 final drive, and cam gears....dynoed at 180/136 with a dc sports 4-2-1. I have both a comptech 4-2-1 and mugen 4-1 header that i can put on. I have significant traction problems bc of the jdm final drive so i was leaning towards the mugen. Which header would you guys recommend?

 

I don't believe the Comptech has a 2.5" collector and the Mugen does. So go with the Mugen and either a high flow cat or test pipe.

 

yeah the comptech is a 2.25 collector, i'll have to modify my testpipe that i have now