So as a few of you might know, I offered to let Emilion at 949 Racing borrow my header to run some tests. It's 2013 and no one has any solid dyno results of a Maxim? Ridiculous. It's a hard to get/expensive header so it somewhat makes sense. I had one laying around and decided it's now or never.
So here it is compared with Chris' hacked to hell and back OEM. If you notice the abrupt bends at the collectors (of the maxim), it goes against traditional convention.
http://i.imgur.com/ETb63TQ.jpg
So what we did was we took a stock 1.8 with a straight pipe and Racing Beat header, dyno'd it... then 40 minutes later put on the Maxim with a straight pipe as well. And here are the results
http://i.imgur.com/vlxGQib.jpg
The RB actually made about 4 more hp between 3800-4600...
so in conclusion... although Racing Beat isn't fancy, or JDM, or cool.. it's the best Header you can probably buy for the Miata.