Rc crawler - make it faster/longer range?
It's not that simple.  Just like a real car, you can't just change one thing and make it faster and still have everything else work as intended.  You don't know what the various design tradeoffs and limits were.

You can try experimenting with different parameters if you want to see what happens, are trying to learn, and are OK if it ends up damaged as a result.  If you're just want it to "go faster", then the answer is "It can't. You bought the wrong model.".