Extremely hot rear centre shaft

[Big G]

There seems to be a common tread with all the DEX410's down the club where the rear centre shaft is too hot to touch after a 5 minute race on wood floor.

Motors range from 6.5 (in mine) to 8.5s in other cars.

This isn't really a problem, but it's puzzling us as to why more than anything. I forgot to check if it happens outdoors