looking for a thread

the one that explains how kv, voltage, and rpm work
tried to search it but with no luck

[sleebus.jones]

voltage * kv = rpm

Done!

ummmm........thanks for the breif explanation but I want the the one that eplains how low kv motors run cooler and more efficient with higher voltage and why

[pedeboi364]

because they do!! lol. in the spirit of real advice, id as brianG or cooleocool

[jayjay283]

low KV/ high voltage pulls less amps so it runs cooler lol, cant find a thread about it

[What's_nitro?]

Originally Posted by jayjay283

low KV/ high voltage pulls less amps so it runs cooler lol, cant find a thread about it

That's basically it. The combination of HV and a lower kV motor do pull less current for a given power output. They are more efficient because electrical losses are dependent mainly on current draw. A high kV motor on lower voltage can make the same power, but it draws much more current and that high current creates more heat. Heat = lost power.

[hoovhartid]

Originally Posted by bustitup

the one that explains how kv, voltage, and rpm work
tried to search it but with no luck

This one?:
http://www.rc-monster.com/forum/showthread.php?t=12697

Originally Posted by hoovhartid

This one?:
http://www.rc-monster.com/forum/showthread.php?t=12697

yes sir that is the one Hoov

[lutach]

Lower Kv motors have more torque and require less AMPs to make the same power as a higher Kv. Simply put it this way:

8S lipos 29.6V X 60A = 1776W (That was the AMP spike I saw in my 8S set up with a Neu 1515/2Y 1100Kv)

6S lipos 22.2V X 80A = 1776W

4S lipos 14.8V X 120A = 1776W

Amps is what will cause most of the heat and the lower the amp plus the torque of a lower Kv motor will give you a cooler running set up. I can also run smaller capacity packs ranging from 2200mAh - 3700mAh 8-10S lipos. he other factors will be gearing, weight, drivign style and smoothness of drive train.

[sleebus.jones]

Originally Posted by lutach

Lower Kv motors have more torque and require less AMPs to make the same power as a higher Kv. Simply put it this way:

8S lipos 29.6V X 60A = 1776W (That was the AMP spike I saw in my 8S set up with a Neu 1515/2Y 1100Kv)

6S lipos 22.2V X 80A = 1776W

4S lipos 14.8V X 120A = 1776W

You're getting all the right answers for all the wrong reasons. :)

The higher voltage is the reason for the lower amp draw, not the KV of the motor. If you're doing the same work, you're doing the same work. If the efficiencies of the motors are the same, then the heat level is going to be the same. If we assume all of those motors are equally efficient at 90%, then they'll radiate 177.6w of heat, regardless of current draw.

The only way to make the same power with less heat is to get a more efficient motor.

[lutach]

Originally Posted by sleebus.jones

You're getting all the right answers for all the wrong reasons. :)

The higher voltage is the reason for the lower amp draw, not the KV of the motor. If you're doing the same work, you're doing the same work. If the efficiencies of the motors are the same, then the heat level is going to be the same. If we assume all of those motors are equally efficient at 90%, then they'll radiate 177.6w of heat, regardless of current draw.

The only way to make the same power with less heat is to get a more efficient motor.

Do you have first hand experience? I do with all the set ups I mentioned. Guess which one runs cooler and longer. Try it out and then tell us how a 8-10S with the appropriate Kv motor compares with a 4S set up and again with the appropriate Kv motor. What you saying will work on paper, but in real world I've found out that it doesn't work out. The numbers I posted was for AMP spikes and the avg. I get from my 8S set up is only 5A while I've seen over 10A with 6S. I haven't had much data on 4S, but with a similar set up as the 8S I've found that my ESC, battery and motor were all much warmer. I've heard of guys avg. over 20A on a 4S set up and that's where you see losses due to heat. You can have all the watts, but electric motors also makes power from torque and that's where a lower Kv motor (Brushed or Brushless) will have the advantage.

[notnodak]

Originally Posted by hoovhartid

This one?:
http://www.rc-monster.com/forum/showthread.php?t=12697

The bottom line it is. Is that a guy on the far right?

[Arct1k]

Not true losses increase with square of current W = I * I * R...

[What's_nitro?]

Hey LT where can I get one of those F12LMR motors?????

Look at the "Most eff. current" column... "910A @ 11V"

Yes, I know it's a typo.....

[lutach]

Originally Posted by What's_nitro?

Hey LT where can I get one of those F12LMR motors?????

Look at the "Most eff. current" column... "910A @ 11V"

Yes, I know it's a typo.....

Must be a typo. Aveox is somewhat hard to find now. You can still get them used and if you're lucky like me find them new. What's even better is that you can send it to Steve Neu and get them fixed if they have any problems lol.