All those limits are depending on who you race with. Namba's limits are quite different. 10s for me, using the motor's kv's on the voltage its meant for.
Good for you. The OP doesn’t plan on racing, and 8S is the voltage those Kv values are “meant for” considering the many folks who
do race those motors on 8S. Why not run on 12S? It’s bound to be faster and some Europeans think that is the voltage those motors are designed for.
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