Lots of Delta vs Wye connection questions?

[Serum]

Rubbish.

In the context you are using; KV values can be perfect, they don't rely on esc efficiency. it's the KV of a motor, not of a setup. This would include the esc efficiency, but the KV value doesn't imply that, this is 'just' efficiency. the KV number represents the number of RPM the motor makes on 1V, some companies measure the other way around; use the motor as a generator and watch at how many RPM the motor produces 1V, while some give the KV values loaded, others give them unloaded. (neu is unknown, but according to Mike, the numbers are loaded)