[VintageMA]

From my conversations with Castle techs the timing is as follows:

Timing change in a brushless motor through software can be compared with twisting the top part of the can of a brushed motor to advance the timing.

With BL unsensored motors the timing is automatically and constantly varied within the software. Changing the setting with the CastleLink only changes the range around which the automatic timing varies.

With increased timing you theoretically get a bit more power out of the motor at the expense of efficiency (ie: more heat). What's really happening is that the point at which the motor would usually fire (the position of the rotors alignment with respect to the magnetic N/S poles of the magnets) is moved forward in degrees (think 360 degrees to complete a full circle) to produce stronger push/pull forces.

My understanding though is that it is not as significant a change in a BL motor as it is in a brushed motor because timing is control automatically by the ESC anyway based on the ESC's knowledge of the rotor position. You may only see a few percent increase in power (pretty negligible).

A few threads and articles around pertaining to the Neu/MMM combo and general rule of thumb has been up to about 3* of timing advance for the Delta wound motors and between 5-10* for the Y wound motors. Apparently the Delta wound motors don't take as kindly and will heat up a lot more.

All things being equal - with the power of the current BL setups - especially a 1515 motor which can easily crank out 3+ HP on strong batteries - I don't really see the need for more power in an already overpower setup.

You'd really probably need an Eagle Tree to see the difference in settings, but I've tried 0* and 3* on a 1515/2.5d with 6S and can't tell any difference. I usually just run timing at lowest setting.