[mbartell]

any motor that uses the came can will work, but what will be faster????
Tamiya makes a series of mini 4wd motors. I have tried(just hooked to the board, not on the car)
plasma dash: took a while to spin up to top speed- this motor needs a LOT of current
atomic tuned: spun up fast and high
torque tuned: spun up nice- and it's a good torque motor
ultra dash: sounded a little faster(higher pitch) than the atomic
stock mini 4wd: (blue endbell) sounded like the xmod stage 2 motor.

Any thing for the audley and canned heat cars will also work.

The plasma dash is really cool looking and the most powerfull motor they make - it can fry a mini-z's circut board. It'll probably do the same to the xmod, unless they used really stout components.
I haven't put them in the car yet- I haven't had time. Just connected them to the leads to find out what they do.

if you go to an audley site, you can find BB motor cases and more powerfull magnets too.
I don't know about slot car motors, but they are worth looking in to.