Why does a 2S lipo (7.4v) has much more low end control of speed than a 3S (11.1v) on brushless system? I mean with 3S I cannot exit low speed corners smoothly because the motor is stuttering, though with 2S is so much better. I tried gearing up with 3S but the stuttering does not seem to be solved this way.

Do you run the same motor in both case? If yes, the cause might be that the the esc has to send more sparse pwm signal to the motor with the 3s for the same effective voltage. You can compensate for this by raising the throttle frequency.

Sensored or sensorless system?

was going to ask the same thing... sensorless I guess

That's not true. I've runned a Serpent 748e in 2S with a 4.5T and in 3S with a 8.5T and the low-speed control is the same. It depends from the quality of your combo (Hobbywing here)

Sensorless. This problem arise for the low speed corners.

I run the same motor. The question is about the battery voltage.

The answer is in the lack of sensor... Sorry.

the whole cogging effect has been worked on for a long time. the timing of the coil to the nuetral plane requires feedback(sensors). the more feedback the smoother it could be.

every time a coil pulls or pushes on a pole there is an acceleration and deceleration rate. the pole is attracted or repulsed from the coil and the current and rotor strength work against each other. cogging comes from this.

you can dampen these micro accelerations by adding weight to the rotor. you are adding to the inertia of the rotor. you can also gear the car so that the gear train dampens these micro accelerations. a 3:1 gear ratio will dampen the motor more than a 4:1.

Thanks. I make lot of effort for a detail acceleration because I run 1/10 touring car. What rc car type you are talking about? Maybe is time to get a sensored system

Thank you that was really informative. So that coil effect depends on the input voltage. That makes sense

yes in that voltage and current make power. a lower turn motor has more power so its a fair assumption to say it has more torque at whatever speed it is that you notice the problem.

The motor is 3000kV 9T from Dragon-RC. Not much of torque but still the problem exist when steering. I also noticed the lower speed I can get with 3S is higher than with 2s.