alright, me and a friend are building a replica of a ghost from Halo 2 (two steerable wheels in the front, one for propulsion in the back) and we need ideas for what kinda motor to use and how to control it.
yeah, we have tomorrow off from school and a junkyard is insanely close. so thats what we do in spare time, videogames and videogame related projects. we once built suits of armor on a weekend just for scaring children.
You should get an electric motor, look for a golf cart(It needs to have the speed controller too, otherwise you will take off REALLY fast). Two PowerWheels motors should do it too(Moved me 120lb+80lb of robot no problem).
It should be connected to the 'gas' pedal. The beauty of it is the programming for it are already done. Though from my experience they tend to get snapped up pretty quick, so you're lucky if you find a complete one.
Get yourself a motorcycle/scooter engine. Make your..uh..ghost...powered by a chain-drive system. This is much easier than any other design. Maybe a lawn mower engine works too but...need for speed, eh?
You can try using the electric motors from car windows, too. You may not be able to go all that fast, but that's what we used in a similar project for OM back in jr. high and it worked pretty well. If you can find a way to pulse-width modulate the signal going to the motor you'll have a speed control. I don't know how easy that stuff is to come by, so that might be a big "if."
You can always try emailing some of these guys if you want tips. I don't know how responsive they'll be, but that robot is huge and heavy, so they know what kind of motors work well: