honesly i would say none as it would shred the drivetrain but if you wanna risk it 36-50 will be enough.
to calculate the speed use BrianG's calculator
Radek
V4 D8 - RX8, XERUN 4168SD
F1-09 - Tekin RS Pro, 17.5t Redline, 2S LiPo
Sakura Zero S - LRP, Saturn 20T, 2S LiPo
*EX-10 Eurus*