Gearing for a Castle Creations 5700

[SamHill]

As the title implies, what spur/pinion should I use for the Castle Creations 5700 on a fairly small tight track? Any ideas.

[erkan]

im running 78 spur with 16-19 pinions on my LRP sphere 5.5 turns bonded :)

[ultima]

I'm running a 16T pinion with my ZX-5 SP. MM7700. 2Cell A123 Batt, Astroturf. I'm just getting 5mins out of it although the A123's are only 2300mah.