Higher voltage versus bigger motor

[dure16]

Does anyone run a 4274 motor on 8S?

I’m curious how the experience differs from a larger motor (say 4082 or 4092) on 6S.

For example:

https://www.rcjuice.com/hobbystar-4274-4-pole-brushless-sensored-motor-1-8-truggy-monster-truck.html

 

[Hector_Fisher]

No personal experience, but if I was a betting man, I'd bet they were somewhat similar in performance. Just that the 4274 setup on 8s would run as cool or cooler than the 4092 on 6s and with the same performance.

What would you be running this in?

 

[dure16]

It would be in a 1/7 infraction

 

[jkflow]

Motor size is unrelated to voltage. The kV is what matters and at what rpm of the motor the bearings and rotor will stay in one piece.
That is your kV rating and typical RPM is 40000 rpm, the only thing higher voltage will do is give you a smaller current (amp) and therefore less heatloss.

 

[Hector_Fisher]

Motor size is unrelated to voltage. The kV is what matters and at what rpm of the motor the bearings and rotor will stay in one piece.
That is your kV rating and typical RPM is 40000 rpm, the only thing higher voltage will do is give you a smaller current (amp) and therefore less heatloss.

I think in this case, the question is about a smaller motor running higher voltage versus a larger motor running lower voltage but pushing more amps.

If electrical power is voltage times current, then it follows that higher voltage would increase power. To the extent where a motor running at a higher voltage -- and drawing the same or less amperage -- theoretically should be at the same level or more powerful than the larger motors running a lower voltage and pushing more amps.

 

[dure16]

I think in this case, the question is about a smaller motor running higher voltage versus a larger motor running lower voltage but pushing more amps.

If electrical power is voltage times current, then it follows that higher voltage would increase power. To the extent where a motor running at a higher voltage -- and drawing the same or less amperage -- theoretically should be at the same level or more powerful than the larger motors running a lower voltage and pushing more amps.

Yes you’ve got it. That’s exactly the question I’m trying to answer.

I (mostly) understand the theory and math, but not how it plays out in the real world.

I’ll make sure to post data logs if I decide to give it a shot.

 

[jkflow]

FYI, in stock Infraction, measure the existing can and see how much room is left. Don't think a 4092 will fit, even the 4082 won't.
74mm, 82mm or 92mm long can and the steering columns are in the way. Some people flipped the motor around for that reason, but that is a different thread.

Again, the voltage matters on the kV, you can always apply more to a motor, but the rpm will destroy it based on kV rating.
The voltage recommendation in the datasheets is only there to limit the RPM's.

A lower kV motor will always generate less heat, it runs more efficient. You have to compensate and upsize the pinion but you will see an overall temp drop at the same speed.

Yes, you can run any 4274 on 8S or 12S or 24S. Yes, they will draw more current. The limit will be your ESC. The RPM will tear it apart, though.

You can run the stock motor on 8S, been there, done that. Keep it under 170F, equals about 1-3 min runtime. Again, you need an 8S capable ESC.
In the real world, it makes no sense unless you want speed runs. If you do speed runs, you are limited to 1 min anyway and will work just fine.

Note: For simple bashing, the stock ESC/motor are the best option imho. Upgrade the fans, and you will always be in the 65mph range.