I'm sorry - I think you misunderstood. I want to turn left/right, not power the wheels. And I am not sure that the batteries are car batteries - They are from a razor electric scooter. They say "sealed lead acid 12v" so I assumed they were car batteries.
Just looked into monster servos and linear actuators on pololu.com, and they all cost more than $75. Are there any cheaper options?
I am building a go kart, with an arduino as the brain. I need to have a gearmotor to turn the front wheels left or right(the entire front axle turns). What kind of motor/controls would I use?
Thanks for the replies! I think I am going to build a rack and pinion steering. Will a smaller motor/servo be able to turn that?