Well I direct swapped out the Flux XS motor with a Castle SCT 3800 motor, and motor temps were 35-40f lower straight away. Makes me wonder what these N38UH magnets are, fridge spec? Will transplant the Flux XS motor into a Hyper 10SC behind a HPI Q-Base (MMP) Esc and see if the lighter truck and easire gearing helps it but didn't expect such a difference.