Proper Wire Size?

I ran a relay on my race only car with trunk mounted battery but you lose this......

The FiTech ECU for Go EFI systems has a special driver circuit that will drive the fuel pump directly, which means that an external relay is not needed. This driver circuit allows both PWM control (pulse width modulated), and direct internal relay drive of the fuel pump. This allows the voltage to be reduced when the fuel demand is low, such as at idle and light cruise.