Satanix runs genuine speed 900's on a 6:1 ratio with a 5s lipo i believe? ( Dave?), whereas Hardwired runs Johnson 850 motors ( basically the same as speed 900's but wound differently so they're faster but have less torque) on a 4:1 ratio with a 4s lipo and much smaller wheels. Basically in the current machine Matt can't fit bigger wheels or a lower reduction with the current motors.