you can buy different sets of gear ratios for torque, all around and speed, you can buy stablizer kits for better handling, you can buy motors for different speeds...lotsa stuff. If you look at the parts shop up there ^ Tinyrc sells lots of these things and more at great prices. Check out
www.questformadness.com for battery mods and other stuff...and spend some time browsing old posts. You will find everything you will want to know discussed 3 times over
welcome!
-nick-