Throttle Minimum is the minimum throttle power the ESC will apply to the motor when the user induces a throttle application. If you want a stronger initial throttle and higher motor start up RPM, use a higher value. Use a lower value or 0 to have a softer throttle and lower motor start up RPM. For Spec racing, higher values will increase the punch feel.
Throttle Minimum can be adjusted through the HotWire device on a PC, and some Apple and Android devices.