Can I get 900F in a charcoal grill? What is the secret to getting a charcoal grill very hot (900F)? Is it even possible? What is the highest temperature attainable in a charcoal grill and what type of wood will produce this? I want to be able to cook Neapolitan pizza.
Alton Brown made a tandoor out of his kettle grill and a terra-cotta pot in Good Eats season 13, episode 17 ("The Curious Case of Curry").  It could reach very high temperatures.

I obviously can't link to that video, but there are plenty of similar videos on YouTube.