Does anyone know what the difference is between these two headers? More importantly has anyone installed a Mugen AP1 header on an AP2 before and if so, any dyno numbers?

 

I can't find a reference at the moment, but recall that the primaries were shortened, and secondaries lengthened, for the AP2 header.

Given how close Mugen is to Honda, and there being no cosmetic need to make a change (the AP2 exhaust tips were made bigger to fill the larger bumper cutouts, but afaik, there were no other changes), I don't think they would have made the design change to the header unless they believe it somehow benefitted the 2.2L engine.

 

^Thanks, do you think the Mugen AP1 would lose power on an AP2 (like the Berk)?

 

i asked the kingmotorsports the same question between ap1 and ap2 exhausts yesterday. no answer yet. but i believe the only change is on the tips. someone tried ap2 exhaust on ap1. but i never know if anyone put ap1 exhaust on ap2.

 

i would stick to a 2.2 header on a 2.2 motor.

 

I have seen posts here of the AP1 Mugen exhaust on an AP2 car, but it was done in combination with a change to the AP1 rear bumper (for cosmetic reasons).

 

you don't want the ap1 mugen header on an ap2. apples to apples my friends.

maybe someone will give you a long winded response. i'm too tired too.

short answer: each will work on the other engine, but not in the best way.

 

Wasn't it King Motorsports themselves who built a Mugen AP2 S2000 for SEMA back in '04 and put on all the existing Mugen parts (including the 2.0 header, since the 2.2L motor wasn't in Japan yet) and LOST power? It wasn't until they designed the 2.2 header that the power gains were right again. I remember seeing/reading about it but can't find anything on it right now.

 

You're correct, but you missed one thing - the magazine article that covered that car (and mentioned the loss of power) wasn't comparing apples to apples. They never dynoed the King car before and after. They compared the King (after) dyno with a stock dynoed car that the magazine had used for an earlier article.

 

^I tried searching but couldn't find any articles on what changes were made and why they were made.