Feigao heat problems.

[BrianG]

A couple more points

1: What is the ambient air temp? If it's ~100*F, that's actually not a bad temp

2: Temps that rise fast but do not get much higher is nothing to worry about, as long as the temps don't keep climbing higher and higher. For a given surface area, any material can dissipate so much heat. The hotter it gets, the faster it dissipates (up to a point of course). At some point, the rate at which the temperature increases will slow and stop as there will be a balance between the delta between ambient air temp/material temp, and the rate at which the motor case dissipates heat. Also, fast rising and falling temps simply means there is efficient transfer of heat.

3: High ESC temps usually means overgeared. I know you say you can't gear lower due to physical constraints, but is it possible to increase the spur size? Or maybe get a diff ring/pinion that is geared lower (not sure how the CRT is set up)?

4: Assuming you can do something to gear lower somehow, I personally would not get a 1600kv motor for 5s. Some may disagree. 1600kv on 5s is under 30k rpm, and when geared for ~40mph, may cause the ESC to stutter a bit at startup because the motor is spinning relatively slow per mph and the ESC may not be able to get rotor positioning feedback as easily at lower rpms.