I mean, hondata published that nothing bigger than 310's would be manageable by the stock ecu...

But how far can the stocker go? 310's with spec c's and 12:1 compression? fpr and vafc... Still running out of fuel up top?

 

i used 450s with my sfc and stock ecu.
idled okay, throttle response was very poor, gas mileage was bad.
but i barely had enough fuel up top because i had to reduce the
pressure to about 30 which is way too low.

Stop being cheap. Do it right once. I learned my lesson.