According to an RC top speed calculator, here are what the fdr's have to be in order to obtain roughly 55mph for each of these xerun motors on 2s lipo

10.5t=  3.486 fdr

8.5t= 4.379 fdr

The calculator rated my old ezrun setup i was using to 53mph but i think the heat would of made it gone slower than 53mph

I prefer lower turn motors but would these ratios overheat the motor and esc? I am getting the 120amp esc which is almost 4 times the amount of amps than my old 35amp ezrun.

Thanks very much for your help.