Race cars = RC toy cars? All I was stating was isolating a power source for the car meaning if he was going to run 2 16v alts only some of that power made by those alts would be used by the car so he might as well add a 12v alt just for the car as it would be seperate and isolated leaving all of the high voltage power made for the system. Also found out they sold out of HC16v batteries with more on the way to stores in about 2 weeks.