would i get improvements from powdercoating a short intake?
would it protect against heat?

I can answer this question in two ways:


1) Powdercoating your short intake on the outside will not enhance it's performance.

2) If you mean powdercoating the inside of it, I would strongly suggest leaving it alone because intakes are designed to have smooth surfaces as it is. The gain of performance from that (if any) is very minimal. And I actually read that too smooth of a surface is not ideal either, that's why port matching (port and polish) on our motors are done not too extremely.

powdercoating is just for looks bro :-) and to keep your sheit from rustin' :-)