mattnin

I see that you are going to make me pull out my physics text book, so here I go..... I will first go on to say that I have a bachelors degree in electronics engineering and a minor in math and I was *very* good in physics, such that my papers were used by my professor to teach people in elementary school based on the way my work was completed. This is actually a very simple physics problem.

Torque = (magnitude of the force) x (lever arm)

In the instance of an RC vehicle where the gearing and mass of the vehicle does not change when comparing two different motors of different windings, this will mean the lever arm will be equal. Another way to explain 'lever arm' in this scenario is that the force required to turn the spur gear is the same whether we use a 13.5t motor or a 4.5t motor, therefore, the lever arm does not change when comparing motors.

Therefore, the comparison of torques comes down solely to comparing the current passing through the coils which in turns pushes the rotor..... And, you have already admitted that torque is proportional to the number of turns.

So now it boils down to how the ESC will energize the coils in the motor. And for simplicity, I only have to describe wide open throttle, in essence, 100% duty cycle which is the total battery voltage.

So now we have it simple to where the total voltage of the battery gets used up on a coil. The 13.5t motor has more winds per coil than a 4.5t motor, winds per coil is proportional to torque, therefore a 13.5t motor has more torque at wide open throttle (available battery voltage).