just curious what is the rev-limiter and fuel cut-off of a pwo campared to that of a pr3. no a vafc will not alter your fuel cut-off and rev-limiter to the best of my knowledge, as you should know it will adjust your v-tec engagement point . the fields v-tec controller will carry up your mph, this do not alter the fuel and the rev, (i think). the apexi is supposed to be better cause it has better tuning capabilities.