Stock vvt, searching power, differences between injectors
 

Hi all, im writin this post cause friend driving with his vvt miata some time attacks in full stock class, he have Access to dyno and have mounted aem wideband, we are looking for some extra power with stock parts and the problem is his miata is incredible Rich at top, he have mid 10 afr, we thought what we can do with it and try to replace ecu from other country with different designation, that gives us nothing, i had idea to put injectors from 1.8 nb bp4w cause they are Little bit smaller, 265 from vvt vs 256 from bp4w but car runs to Lean, something like 17 at Cruise and 14 to 13,5 over 4000-5000 rpm, difference is bigger than i expected so i think vvt ecu have shorter injection time than bp4w, there is any option to make stock vvt Little bit leaner? Or maybe injectors between 256 and 265cc? It looks like some 260cc Will be perfect

Fuel pressure, just like every Spec Miata.

If im not wrong he cant use aftermarket fuel pressure, but fun fact today is much better than yesterday, ecu make some corrections or something, we have 12.5 at top idle and Cruise is good, only around 4.5k rpm something is wrong and for moment is to lean, around 16.5 afr