Depends on what kind of motor you are looking for. 1/10 scale or 1/8th scale? For 1/10 scale this is really powerful: http://www.lrp.cc/en/products/electr...d-30t/details/

For 1/8 scale I am not really sure but this seems very powerful: http://www.castlecreations.com/produ...le_motors.html