if i use a vafc on my turbo z6 with stock injectors will that mean my settings should be on lthe + side and not on the - like with bigger injectors

 

u need to get proper fuel mangement for your engine before youdamage your motor. get some bigger injectors, a high flow fuel pumpandget ur ecu chipped and tuned by a reputable tuner. this is the only way you are going to have a reliable and powerful turbo setup.

 

VAFC only adjusts air/fuel ratios, where actual tuning can adjust timing and various other things that are necesarry for a proper tune. ^ Go with what Skrap said