2200kv MMM

[nuz69]

No. A 1512 1.5Y will short your runtimes if geared for the same speed, because it won't be efficient at all in a truggy. The motor is too short. The runtimes don't depend of your motor, unless its undersized, but of your voltage, your gearing and the weight of vehicle.
To increase runtime you need to increase efficiency, if you cant change your motor, you need to up you voltage and reduce the gearing, to keep the same power and reduce current.
More over your timing is not right for Y windings. Best efficiency with the 2200kV 1515 1Y motor is 4-5, not 0.

==>Try first to reduce a little your pinion, set the correct timing. Punch at 75% is good, you don't need more power at start.

A Castle 1518 1800kV will be more efficient in a truggy on 4 or 5S, and the 1520 1Y 1600kV on 6S with low gearing would be the best solution ever to have insane runtimes, but I do not know if the rules permit theses motors...

[RC-Monster Mike]

Originally Posted by nuz69

No. A 1512 1.5Y will short your runtimes if geared for the same speed, because it won't be efficient at all in a truggy. The motor is too short. The runtimes don't depend of your motor, unless its undersized, but of your voltage, your gearing and the weight of vehicle.
To increase runtime you need to increase efficiency, if you cant change your motor, you need to up you voltage and reduce the gearing, to keep the same power and reduce current.
More over your timing is not right for Y windings. Best efficiency with the 2200kV 1515 1Y motor is 4-5, not 0.

==>Try first to reduce a little your pinion, set the correct timing. Punch at 75% is good, you don't need more power at start.

A Castle 1518 1800kV will be more efficient in a truggy on 4 or 5S, and the 1520 1Y 1600kV on 6S with low gearing would be the best solution ever to have insane runtimes, but I do not know if the rules permit theses motors...

This isn't necessarily true and could be misinterpreted. A 1512 very well could be more efficient in a truggy with the right conditions and the right driver. A smaller motor will very likely achieve more runtime in ideal conditions as well(as long as it isn't too small) - it simply takes less power to move itself. I am not saying the 1512 is the answer, but i wouldn't flat out say that it isn't, either. Likewise, the 1518 may very well achieve less runtime on the same 4s battery in this application.

5s on the 2200Kv motor is quite aggressive as well - I am not convinced that this is as efficient as 4s in this particular application to be honest. I don't know if you could achieve a low enough gearing for starters, so current draw very well could increase rather than decrease. I doubt it is as drivable, either. Zero timing will be the most efficient with pretty much any of these motors, but you won't likely find more than a few seconds of runtime when switching from zero to 5 degrees anyways. Higher timing will hurt efficiency more at low speed, which is where most of the time is spent in RC racing - timing advance reduced torque and increases rpms. You torque to accelerate a truggy, so zero timing gets my vote.

My suggestion would be to simply gear down a tooth and set the LVC to 3.1 or 3.0 volts/cell to gain the runtime if you are using good batteries. And stick with Zero timing.

[nuz69]

According to Patrick the best efficiency for Y Windings Castle motor is 2-4...
A 1512 motor is clearly undersized for a truggy under race conditions, I experienced myself higher runtimes with 1515 than a 1512 in a buggy, so imagine in a truggy...
When the motor is too short, it eats a lot of amps because of its low ratio torque/amps.
5S with increased punch control and gearing for same speed than 4S won't draw more amp than a 4S configuration IMO...

[RC-Monster Mike]

Originally Posted by nuz69

According to Patrick the best efficiency for Y Windings Castle motor is 2-4...
A 1512 motor is clearly undersized for a truggy under race conditions, I experienced myself higher runtimes with 1515 than a 1512 in a buggy, so imagine in a truggy...
When the motor is too short, it eats a lot of amps because of its low ratio torque/amps.
5S with increased punch control and gearing for same speed than 4S won't draw more amp than a 4S configuration IMO...

It isn't black and white 2-4 degrees, though. Here is the rest of what Patrick stated regarding timing - "Timing of about 2-4 will work best with the four pole Neu or Neu/Castle motors. They will accept more timing, but will run a bit hotter.

Well, I wish I could tell you exactly, but it changes based on load, RPM, and voltage. High RPM setups (6S, low load) will get maximum efficiency with a little more timing, low RPM setups will get maximum efficiency with a little less timing"

If you read into this a little deeper, you may draw from it that higher timing would be beneficial in high voltage oval racing, for example, where the motor will spend considerable time making "high rpms" with fairly low load - a track racing application would benefit from lower timing(lower than 2-4 degrees would be zero), as most of the time is spent in a much lower rpm range(and higher load from constant acceleration). I already mentioned that I doubt there would be a considerable difference with 0 or 5 degrees timing in reality, but when you are cutting it close for runtime, every bit counts. :) As a side note, when a motor's timing is advanced in one direction, it is effectively retarded when reversed(brakes). Motor braking with higher timing would theoretically decrease efficiency in this scenario(retarded timing decreases efficiency, torque - this would definately be the case with a sensor based ESC and mechanical motor timing, though may not apply here - depends on ESC).

I am not sure the 2200Kv motor can be geared for the same speed on 5s in this application, so the potential for higher current consumption is present(would need a 10t or 11t pinion, which may interfere with the diff drive cups or not be compatible with the motor mount). Also, it is not "clear" that a 1512 is undersized in a truggy. It depends, just like timing, on various factors. Someone on this site has reported excellent results with the Tekin 1400Kv buggy setup in an XT8 truggy for example - the 1400Kv Tekin buggy motor is essentially a sensored 1512 motor. A 1512 motor can make plenty or torque for a truggy. Perhaps not for you personally, but you may drive differently than others, and may have other factors as well. If you are trying to reach 50+mph in a 10+ pound truggy, then a larger motor is likely the better solution, but for an average sized track and 35mph speed with a sub 10 pound truggy, a 1512 that is geared, volted and selected appropriately can be a better option for overall performance - including runtime. It could also overheat in the hands of an erratic driver with lower quality cells and a poor setup(as could a 1515, 1518 or any other motor for that matter). Bigger isn't always better - especially when you are trying to achieve maximum runtime. A 1512 will naturally draw less current than a 1515 of the same Kv to a certain load.


At then end of the day, I still suggest that this user first tries to drop down 1 tooth on the motor pinion, lower the LVC threshhold to 3.1 or 3.0 volts/cell(I use 3v/cell personally) and use zero timing for optimum runtime results. I also prefer to NOT use punch control, as I find it makes the throttle feel "muddy" - I prefer using the throttle curve or throttle EPA adjustments to tune the throttle to my trigger inputs. This is based on my experience racing brushless vehicles for the last 10 or so years. :)