I race 13.5 in all my classes and I run the Hobbywing V10 motors. They are freaks, they stay cool no matter how i gear them and have a ton of torque. They all come with 12.5 rotors and are cheaper then most anything else. I can pull taller gearing and be faster down the straights. I switched from my Novak Vulcans for them. Just my two cents though.