I think u are new to car modifications...
Stage <0.5 = Stage1C
Stage <0.7 = Stage1B
Stage <1.0 = Stage1A
Stage <1.5 = Stage2C (a pw member has a corolla XRS with this modification)
Stage <1.7 = Stage2B
Stage <2.0 = Stage2A
and so on...
Formula for calculating stages:
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
and so on...