Savage project idea. Please read have many ?'s!

[othello]

Both motors are able to generate the same amount of torque, but the motor with more winds (ACn22/45/3) will need less Amps to generate the same amount of torque as a ACn22/45/2. Theoratically 1000 vs 1380kv = 38% less Amps. Meaning a ACn22/45/3 drawing 30A at a given voltage would require your ACn22/45/2 to draw 41,4A to generate the same amount of torque. This is how i understood it.

The ACn22/45/2 with 1380kv would be a relative hot motor on 10s1p A123. Under load at full speed voltage of 10s1p A123 will drop to 28-30V. Giving you rpms of around 40000rpm. Seems a bit high for my liking in a heavy truck. I used a Neu 1512/2Y (1400kv) in my 9lbs buggy and saw rpm levels of up to 44000rpm (with 10s1p A123). Which seems alright for a lighter buggy. The same motor in my heavier truggy (11lbs) with the 10s1p A123 reached 36000-38000rpm under load geared for slightly lesser speed than in my buggy.

It really depends on which rpm band suits your gearing options most. Expect 38000rpm with a ACn22/45/2 (1400kv) under load (depending on your gearing) with 10s1p a123, The ACn22/45/3 (1000kv) will more likely be at 28000-30000rpm with 10s1p a123 or 33500-36000 with 12s1p A123.

With 12s A123 you will have 20% more energy in your car. Due to having more wheight in your car this won't translate into 20% more runtime. But having more volts tranlates in lesser Amps to generate the same amount of power. Giving you slightly more efficiency. You might end up driving 10-15% longer with 12s. This is only a guess. I saw a jump in runtime of around 1 minute when driving with 10s1p A123 in comparision to a 9s1p setup.

What you also might consider is running an ESC at its voltage limit is always more risky then using it with a safety margin of 1-2 cells less then its rated max. So look at the specs of the HV85 or HV110 -> 8s lipo is comparable with 10s A123 from a voltage point of view. When coming fresh of a charger a123 cells are at 3.6-3.7v per cell. Droping quickly to 3,3v when used. What you also might consider is flight ESCs have a slower ramp up time when revving your motor up. Investigate on this further or you might end up with a setup which feels a little sluggish when it comes to accelerating.

On a side note the ACn22/45 series is a little heavier than a Neu 1512. Which i would consider beeing on the light side for a heavy truck. The 1512 worked well in my truggy but run hotter then my Neu 1515. More mass means more energy in heat can be stored. That is why a heavier motor is not as critical then a lighter motor. The ACn22/45 will have enough power to push your truck but i would expect it to run a little hot due to it's "small" wheight. If you're not a speed freak this will not be an issue. A heavier motor can be geared higher without breaking a sweat. But those are all estimations. Don't know if someone already tested this motor in a heavy truck.

hope this helps.

EDIT: like lutach stated. Those are continouus ratings. My average amp draw is between 15-21A when looking at a complete run. My Neu 1515/2y is rated at 50A if i'm not mistaken. I reguraly see peaks between 50-100A. But they only last for 1/10 tenth of a second under hard acceleration.