If it were me, I would try a 14 or a 15.... If you're doing speed runs, you could probably my get away with a 16t paired to the 45.

Fwiw....I'm running the same truck, and ESC. Only difference is I run a buggy 1900. I run 15/45 on a med-high bite track. I might see °170ish after 10 min of hard race action.