12.3, 12.5, 13mm rotor's - Which is better for BL motors
 

Which rotor size is better for 17.5 and 13.5 carpet racing with timing?

Which would be better for no timing?

i have tried 12.5 and 13mm high torque rotors in 10.5 with timed esc and found no gain currant draw is heaps higher lipo 50c 5000 not lasting 4mins in a race temps heaps higher only advantage was is gave the tekin brakes. have not tried 12.3 but would guess it would work better with a higher fdr. stick to the std rotor

Changing rotor sizes is like motor timing or gearing. You move from one end of the spectrum to the other. It's just another tuning option, so there really is no "better", just personal preference.

12.3 is for high speed - oval racing

12.5 is the stock rotor most manufacturer use

13 more torque for tighter courses

yea, except for the fact that SP's come with a 12.3 and have many on road wins, I would agree

go with this for your answer