Voltage, Amps, and Heat

[DrKnow65]

Another motor question for you guys,

I have a XXXT I'm running a MM esc, and a cs325700 (5700KV) motor, I'm geared as small as I can get and the motor temps are just acceptable (150') after a good hard run. (2S lipo now, 3S later this month)

I want to step up to a NEU motor (thinking 1509/1.5Y) 2400kv, use 4S lipo's and have a cool running setup.

The question I have is,
I also have a HYPER7 I'm wanting to run brushless, I would like to use the MM/NEU in both setups, what is the smallest NEU I should use in it on 4S? I'd like to have one motor/esc that would work in both (xxxt-hyper) untill the MMM comes out for the hyper7...

The MM esc, is modded with heatsinks on both sides of the fet board (wind tunnel dual fan setup) and runs cooler than ambient in the XXXT no matter what gearing or how hard I drive it, so I'm not worried about the esc.

One NEU, not WAY too big for the xxxt, not WAY too small for the hyper7, 4S in both cars... will a 1509 series be ok? need a 1512 series? will the xxxt steer with a 1515 hanging off the back?

[zeropointbug]

Yeah, I think there is lot's of misunderstanding as far as system voltages go...

Like you said Serum, sometimes people don't mention that you HAVE to run a lower Kv. motor on the higher voltages you use... so some guy will think: "Oh, so a 8XL on 6s will be more efficient than a 8XL on 4s"...

Although, that isn't to say an 8XL on 6s would be LESS efficient... as it could be the same, it's just that you are putting say over 2200watts through the motor, and multiply that by your efficiency, you get the idea. They could both be ~70% at peak load, but the 6s setup will be drawing alot more power, thus dissipating more heat, making it seem like it's less efficient.

We just need to keep it simple/stupid, and have a rule of thumb 'target rpm' for each motor size/brand, and adjust your motor wind according to your voltage selected, or visa-versa.