The core does everything without a booster needed and works fine without the fan. i used one with a ko reciever, 12th savox servo and a dynamite 13.5 motor with no issues. :thumbsup:

Thanks everyone very helpful.

I recently came across the vampire racing S esc that claims its a 1s 2s esc, bit cant for the life of me find out if it needs a booster

Vampire S has a 6v/3amp BEC inside ... You won't need a booster chap.

These are the same as hobbywing 1s / teampowers XPS and LRP. I understand it that the circuit guys run a booster to ensure max speed of their steering servos, but I've never needed it.