XO-1 1717 (1650kv) vs Neu-Castle 1717 (1580kv)

[RC-Monster Mike]

I am pretty sure the 1st pair of numbers indicate the stator diameter and the 2nd pair indicates the rotor length - a 1717 has 1.7" stator diameter and 1.7" rotor length(magnet). A 1521 would then be 1.5" stator diameter and 2.1" rotor length.

[ta_man]

Originally Posted by RC-Monster Mike

I am pretty sure the 1st pair of numbers indicate the stator diameter and the 2nd pair indicates the rotor length - a 1717 has 1.7" stator diameter and 1.7" rotor length(magnet). A 1521 would then be 1.5" stator diameter and 2.1" rotor length.

That was my understanding too, but then given this info from Patrick:

Originally Posted by Pdelcast

We developed a whole new stator and rotor design for this car -- it uses a shorter and lighter rotor for faster spin-up, and is up to 4% more efficient than the original 1717.

... how can it still be a 1717? If the rotor is shorter?

Wouldn't that make it a 1716 or a 1715?