電變的選擇

LRP AI Runner Plus Reverse - Rated Current : 75A
Futaba MC330CR - Rated Current : 200A

以上两個電變，那個效能最好？

depends how much you willing to pay

if your pocket is deep, you might consider take the higher current rating one. (200A limit, you can run a 8 turn or even lower modified motor with it, if i remember correctly.)

also check the maximum power that the ESC allows, (as the same rule as above, the higher the better)

Don't get the A.I.  
I used it, but I felt that it's limited the motor.  Can't go to peak rpm.  I tested the same motor (27T) on a Tamiya 101, and even the 101 ESC can make the motor run faster!!  

LRP sucks!!  (at least the A.I.)  Use Futaba or Novak la.