i used my moter and gears to multiply the speed. unfortunetly i ran out of gears so i could not make it any faster. the design is simple. moter on a rod with big gear. that big bear interlocks with a small gear. on the small gears rod there is a big gear. the big gear interlocks with a small gear. the small gears rod has a big gear on it. that big gear interlocks with..... ect. ect. ect. 2 cogs were atached to each other with a chain. thus, it is four wheel drive. hope you enjoy!!!!