I have two kids (one of each) that just recently got some power wheels. One is a Toy Story 3 Tot Rod and the other is a 6v Jeep (not sure of the model). I'm always in for a little more speed and found this site. I have already got a 550 turn motor from my friend's rc car. Going to order a Gruber battery and start from there. I'm interested to see what can be done with these.