Advice stepping down to a lower kV from my 1800kV 4074 for 6S?

[chili81]

This was my first build where I had to pick the driveline, and I think I went too high. I'm on 6S with a sensored 1800kV 4074 (leopard) 15T. I understand the kV and gear ratio stuff, but don't really have a feel for the impact of motor size. I guess bigger is more powerful probably, but that's it.

So mainly I want to gear down, and also it gets too hot too easily without fans as I have it currently.

Debating between these two (mainly because they are the lowest kV I've been able to find in that size range sensored):

4068 - 1400kV
4074 - 1550kV

Would be nice to drop all the way down to 1400kV - about a 20% drop from current. But it's a 4068 vs 4074. What kind of difference would that mean? Slightly less torque I'd imagine? Maybe that would actually be good - reduce the driveline wear a tiny bit on 6S. I wonder about heat though... would be nice to not have to add fans. Does that seem like. a realistic goal?

Btw 6S it's really just a convenience thing. My 'fleet' is really 3S/6S leaning, so I'd like to just stick with that set of batteries.

... oh, I also wouldn't mind an extra 6mm of space for my crammed max8 g2.

 

[Hector_Fisher]

And here I am running my mt410 on a 2050kv kraton motor and 15t pinion...

Just my opinion, but for this size of truck on 6s the size of your motor matters very little. I take the example of my kaiju w stock motor (4068, 2100kv i think?) and mt410 with the kraton 4074 motor. I've ran both on a mix of 4s and 6s. Both have lots of power on 4s, maybe the mt410 slightly more. But on 6s, BOTH have way more power than I could ever use. I've never considered the kaiju on 6s any less powerful than the mt410 (or at least what power I can actually put down to the ground).

For heat: that's kind of going to be a roll of the dice. I'd wager the 4068 would run slightly warmer due to the size, even considering the lower kv. Whether it would be too much though? I could only guess that that point.

Personally, I'd just run a fan and pick whichever motor costed the least.

 

[Nicochau]

I think I would go with the 4076 1550kv. Totally get the fleet homogeneous thing. Should be great on 6s, nice and tamed.

 

[chili81]

OK cool sounds like I'm on the right track at least.
I did go ahead and throw a fan on it last night, so I'll take it out today and see how hot the 1800kV gets with the fan on just for curiosity. Then probably still grab a cheap slower one to give me more gearing flexibility and throttle range.

 

[nub]

I don't know, I think I'd go lower like in the 1200KV range if I were to go 6S. I have a 6S Kraton with the typical go to Max6 and 1650KV on a 20T pinion. That's a much heavier longer wheelbase and even easing it to it on a large field full trigger is a backward flip on to your lid.

I couldn't imagine a MT410 on 6S being more than a 1/4 to 1/2 trigger max. I would put a fan on what you have and see how it goes. I think I have a fan on everything but my crawler.

 

[chili81]

I don't know, I think I'd go lower like in the 1200KV range if I were to go 6S. I have a 6S Kraton with the typical go to Max6 and 1650KV on a 20T pinion. That's a much heavier longer wheelbase and even easing it to it on a large field full trigger is a backward flip on to your lid.

I couldn't imagine a MT410 on 6S being more than a 1/4 to 1/2 trigger max. I would put a fan on what you have and see how it goes. I think I have a fan on everything but my crawler.

That 1400 was the lowest I could find in that size range, sensored. I think if you go for a smaller motor, they tend to even be higher kV - but not sure. Do you know any in that size rage that are as low as 1200?

 

[SlapHappyPappy]

I like the 2050 Arrma blx set up on 6s. It has taught me throttle control and I have long battery life because I can never go full throttle. Just got some 4s backflips and they work great with it.

 

[Klappars]

I used to run a TP power 40x74mm size 1580kv in my ET48.3 on 6S with a Castle Mamba Monster X.

The truggy had Backflip LP tyres, a couple m2c upgrades and an unbreakable bodyshell.

On 6S with a 16 or 17t pinion, it would hit at least 52mph on grass and closer to 60mph on a road, it had loads of power and would wheelie on command and backflip pretty well off jumps. I ran it pretty much flat out in an open grass park and found the motor would run around 65-70°C which was well within safe temperature.

I’d highly recommend such a motor for your MT410, it will be crazy overpowered but I guess that’s what you are looking for?

 

[nub]

Do you know any in that size rage that are as low as 1200?

Look at TP Power