i dont really know what a fuel charger is. i assume its a component that ionizes fuel or maybe pressurizes it etc..
So assuming the stock B16 makes 160hp and after the modification, the car is able to make 180hp at max, its going to be a Stage 1C car Or Stage 1.2.
im posting again the legend/key for the stages:
Stage <0.5 = Stage1C
Stage <0.7 = Stage1B
Stage <1.0 = Stage1A
Stage <1.5 = Stage2C
Stage <1.7 = Stage2B
Stage <2.0 = Stage2A and so on..
stage 0.5 (1C) = has 50hp more than stock
stage 0.7 (1B) = has 70hp more than stock
stage 1.0 (1A) = has 100hp more than stock
stage 1.5 (2C) = has 150hp more than stock
and so on...
i hope u now understand..