I totally agree with this. I think it depends on the settings of the motor controller. I am rolling dual 6355’s on vesc-x in FOC mode on my custom board, but my initial torque is no where near as strong as my bamboo GT. We all know that the bamboo GT is just using 5065’s. However at around 10mph or so, the torque is much stronger and would easily blow by my bamboo GT.
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Uhm that’s a fair question.
I’m going to log both of my boards, but I ride almost everyday against another dual 6355 and the difference is huge
Do you two have the same settings and roughly the same rider weight. I can imagine that the 6374 are a bit more powerfull at the same amps. And by this they should be more efficient. But in theory if you pump 80 A in both motors the power needs to go somewhere. And if the 6374 are a huge difference then the 6355 must transfer a lot of the power in heat. But that is not the case in reality.
I guess the biggest difference is the higher resistance of the 6374 because of more copper length. Which gives you more power at low speeds. Because the duty cycle (volts) need to be higher to reach the same amps. And power is volt * amps. So with more volts for the same amps you reach a higher power. But that is then a bit of a disadvantage at higher speeds. Because close to the max duty cycle the power is less compared to the lower resistance motor.
Best would be to have have videos with my app to see the difference of the 2 motors. Sadly i don’t think i will find the time in the next days to compare them.
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Doesn’t really seem to be a fair comparison. Running the 6374s at 12s 43.2×80= 3,456watts. And 6355s at 10s 36×80= 2,880watts. Eboosted you also mentioned 6355s are faster, but should be almost the same speed based on running at different voltages. With erpm at nominal voltage being 57,960 and 57,456 between the two. So seems like kv is not accurate or you’re running different pulleys/wheels. Less gearing on 6355s means even less torque.
I agree with you about the voltage, I have run 12s and it creates substantial more torque than 10s in my opinion. I am running my 6355s and 6374s both on 10s and though I can feel an increase in torque, it’s not knocking my socks off.
Here is some prop thrust data from the Scorpion web site:
A motor with a shell diameter of 66mm and a length of 70mm (SII-5535 190kv) produces 12.4kg of thrust with a AP*C 20x10 prop at 37v (10s)/ 90.8A/ 6430rpm.
While a shorter stator motor with a shell diameter of 66mm and a length of 60mm (SII-5525-195kv) produces only 9.2kg of thrust with a AP*C 20x10 prop at 37v (10s)/ 58.9A/ 6450rpm.
While 2 motors are not statistically relevant and we are relying on what ever was Scorpion’s test method, they do paint a picture. At full gas the longer motor is pushing 1/3 more thrust and drawing a 1/3 more current/ amps at load.
I am surprised at ~6440/50rpm there such a difference. But the SII-5535-190kv is rated at 3900w/ 95A cont. while the SII-5525-195 is only rated at 2800w/ 80A. There is also a +198g weight differance which is close to 1/3 of the weight of the SII-5525-195kv.
I would expect the difference between a 6374/ 6355 to be even greater as the difference in stator length is proportionately greater.
But its not all doom and gloom for the shorter motor, while the data pool is too small to say for sure it does look like it could be more efficient.
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There are to many variables that are very different between the two. The way the throttle on vesc works also makes it hard to compare. If you make setting changes, then your throttle curve changes. And since you’re controlling current/watts it’s difficult to see how much power a motor has especially at slow speeds where you need lots of power. Compared to duty cycle like car ESCs have which sends all the power right away. Basically if you were to adjust your throttle curve so it’s a ON or OFF switch to get all 3000+watts from a standstill it will feel like it has way more torque.
I made a pretty nice test today.
I removed the 6374s 190KV and mounted 6355s 190KV on my Trampa, everything else was left untouched, I wanted to compare for myself if the bigger motors were worth the weight and went to ride my daily commute.
I was expecting a lot less power and torque from the 6355s but I was impressed with them, the sound is more high pitched, the acceleration from stand still is a tad lower but not at all noticeable, at low to mid speeds the acceleration is almost identical when I was applying 3/4 throttle as I ussualy ride on that road, board felt light and smooth, the main difference was at full throttle from stand still, on my 6374s I need to be way thrown forward to avoid being thrown back at maximum throttle, on the 6355s it was a little bit more controllable and easy to ride, but the difference is not day and night. BTW I weight 154lb so make the math for your weight.
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I didn’t notice that much difference either except when going up a fairly steep hill. the 6374s go up easier and with less throttle. I think the extra torque helps in this situation.
This makes Hope for my 2x 6364 190kv trampa build thanks.
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You should step up to 6374 instead since the stator size of the 6364 is essentially the same as the 6355
I know. But the motor mount from Idea, does not fint 6374
Trampa trucks should fit dual 6374. Not sure what you mean by the mount not fitting.
According to @Idea wich i bought the motor mounts from, for my Trampa urban carver. The biggest motor (length) that can go on, is 6364. And thats okay with me, and since @Eboosted claims no to much of a difference, then i`m fine with that.
The stator of 6364 is way more similar to a 6355 than a 6374. A trampa truck can easily mount two 6374s, unless you use extremely large belts
6374 will fit street carver, only not 6374 sk3’s from hobbyking
He’s working on a prototype to fit 2 x 6374s for me at the moment
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Sounds awesome 
Is the weight difference really that much noticeable? I figure at most it would be a pound or two off… so 23 pounds instead of 25???
Each motor is about .5kg heavier, so 1kg~ total