It is almost as simple as that. The caveat is that different injectors have different open/close latency. It seems it is not so different between OEM 220 and chinese suzuki gsxr 270.
What I can say - many people are successful with just 270cc injector and JDM ECU on klx300 (without fuel controller!). Few need fueling refinement. Obviously everyone has slightly different set up, but I still didn't figure out why is that.

 

It's all subjective opinions, non data driven, non verified, dyno butt crap.
Has anyone ever checked the result of installing a 270 injector via back-to-back dyno runs ?

Dyno-Butts and subjective opinions regarding results have no merit - my dyno testing proved the engine will run "perfectly fine" with horrible fueling -f ueling that ranged as lean as in the 14's and as rich as in the 10's. h
Hell, my bike never felt "more alive" than when I was feeding it horribly rich fueling - WOT in the 10's :1. So much so that even after a dyno run showed the truth, I still ran that fueling for a while.

That is when I learned that my Dyno-Butt was just as flawed as everyone else's..

 

Yeah, I really thought that but it was perfect as soon as i put on the 300 ecu. I was just about to get bung welded into my header cause I have a fast AF guage. A lot would have been answered if I had done that. I could have seen if the AF got non linear in closed loop,, transition to open loop, etc.... I'm basically landing where this thread has suggested 300 with no stp kdx snorkel and a little extra fuel in the middle. Seems to me with the stp removed there might need to be a little more fuel right where the dip shows up on dyno's.. Is this true? Thanks guys!

 

IIRC, if the airbox and exhaust are left stock, removing the STP ( secondary throttle plate ) does not cause AFR to go so lean as to be of concern. I think I recall the area of most concern (midrange) makes it into the mid 13's. THis is not performance fueling but should not cause any harm as it is limited to midrange ops only - the ops that were muzzled with the STP.

 

You just need to get your "Dyno" recalibrated..."Butt" I agree with you .

Audible noise can be very deceiving as well...louder doesn't necessarily mean more powerful.