Turn count is how many times wire is wrapped around each stator pole of a brushless RC motor, written as a number plus T. Fewer turns means higher kV, more RPM and less torque per amp.
ROAR classes by this number without ever explaining it: §1.13.1 lists “# of Wire Winds” recommendations of 25.5T for carpet and 21.5T for asphalt in 1/10 FWD. kV is the other half — revolutions per minute per volt, measured with no load. Here is the part that costs people money: T and kV do not convert across brands. So Dialed puts a 13.5T at roughly 3,200–3,600 kV, while Hobbywing’s own spec for the XeRun V10 G4R 13.5T is 4100KV, above that entire range. Same wind, different motor. ROAR writes its rules in T, not kV. Neither T nor kV has anything to do with mechanical endbell timing, which is the separate physical adjustment made by rotating the motor’s endplate.
Buy by kV alone and you can land outside your class's turn limit; buy by T alone across two brands and you can end up with meaningfully different power for the same legal number.