hehehe, doesnt NOX change the internal parts?
I have 10 friends all did just that, .
how much money you got? 100,300,3000?
what do you want , lowend power, wide band or just high end.
really depend on what you use it for,
off road speed, or rock crawling or dual sport.
must you be smog legal ( the most important of all questions , really)
the best gain with least bucks
1- throw out rear seat. roof rack
2 - carpets?
3- passenger seat.
4-power pulleys.
if you drive over 5000 RPM ,you might get a tad more power with a real cold air setup (not silly engine bay kind) but the real external induction.
but many show a drop in power (real dyno) when ever you force air into
a MAF valve (like yours). It wigs out.
playing with the exhause for many kills low end torque and moves it to the other end. of the RPM band.
so again, where are you going?
if you want to see what really works and what doesnt,
look here.
Flyin' Miata : Dyno results