Run times and Motor Sizes / KV

[TL01magic]

Am pretty decided on getting a CC ESC / Motor combo.

now wondering about run times.

Between the CC 1515 (2200kv) & 1717 (1650kv) for a Mojave on 6s which would give longest run times? Am thinking the 1515 is best since it would be much closer to it's max compared to the 1717.

I imagine the 1717 would run MUCH cooler, but would also eat through batteries more quickly. I figure I can limit the motor amp draw via the ESC, but thinking the Mojave is too light to get the best out of the motor and that the 1515 is a better match for the size / weight of the mojave.

Thanks for any replies / input.

 

[Exc3l]

1717 is a better choice. The 2050kv that comes in these cars would be the max kv I would run. The 1650kv is a good choice. Have you considered the Hobbywing Max6 1650kv combo? Save $100 and get like some scorched inner fenders or some upgrades.

 

[SrC]

1650kv setup without question. Your logic is a bit off.
And the Mojave is not considered a light rig at all.
1650kv/1750kv is pretty much the sweet spot for the weight of this rig. Has more torque, and thus will run cooler than a 2200kv motor.

 

[TL01magic]

1717 is a better choice. The 2050kv that comes in these cars would be the max kv I would run. The 1650kv is a good choice. Have you considered the Hobbywing Max6 1650kv combo? Save $100 and get like some scorched inner fenders or some upgrades.

Thanks for the reply; what about the difference in motor size with respect to run time.

Totally appreciate 2050kv @ 6s (and tall gearing) is max for mojave, am thinking more so run times, not max RPM.

For example, pretend I would gear both set ups to be roughly 50kmh / 30mph which would have longer runtimes

I guess that's the better perspective; so for each case below which system would provide longest runtime

top speed of
30mph
40mph ( I figure this would be the best top speed; guessing an avg. speed per run of 20mph)
50mph
60mph

So I guess question is would the 1515 be most efficient for 40mph top speed, or the 1717? If the 1717 doesn't have work hard at all to do 40mph top speed maybe too much battery is going into just running the larger motor.

To use hyperbole to highlight my point, if I put a 20lbs massive motor in, far more of the battery is powering the motor just to turn the rotor, the extra motor weight ect, the load of the mojave would be nill comparatively...i.e. WAY too much motor. Much more subtle comparing 1717 & 1515 but wondering if one is a distinctly better choice from this perspective. of course if the 1717 is more efficient that'd make me happiest lol

1650kv setup without question. Your logic is a bit off.
And the Mojave is not considered a light rig at all.
1650kv/1750kv is pretty much the sweet spot for the weight of this rig. Has more torque, and thus will run cooler than a 2200kv motor.

Thanks for the reply and please by all means correct my "logic"; am clearly thinking about this with intent to understand.

I think you're both selling me on the 1650kv! Just a big drop in KV, so need to gear it up some. And concerned at that point I will lose run time compared to the 2200kv.

 

[SrC]

15 minutes run time is normal. Give or take. Just have spare packs to change out. I hope you don't expect to drive your rig for 30min to an hour on one Lipo. You are stressing too much on run time. There are many other variable factors to consider. Like gearing and Lipo Mah and C ratings and ESC settings.

 

[Sandracer_NL]

Thanks for the reply; what about the difference in motor size with respect to run time.

Totally appreciate 2050kv @ 6s (and tall gearing) is max for mojave, am thinking more so run times, not max RPM.

For example, pretend I would gear both set ups to be roughly 50kmh / 30mph which would have longer runtimes

I guess that's the better perspective; so for each case below which system would provide longest runtime

top speed of
30mph
40mph ( I figure this would be the best top speed; guessing an avg. speed per run of 20mph)
50mph
60mph

So I guess question is would the 1515 be most efficient for 40mph top speed, or the 1717? If the 1717 doesn't have work hard at all to do 40mph top speed maybe too much battery is going into just running the larger motor.

To use hyperbole to highlight my point, if I put a 20lbs massive motor in, far more of the battery is powering the motor just to turn the rotor, the extra motor weight ect, the load of the mojave would be nill comparatively...i.e. WAY too much motor. Much more subtle comparing 1717 & 1515 but wondering if one is a distinctly better choice from this perspective. of course if the 1717 is more efficient that'd make me happiest lol

Thanks for the reply and please by all means correct my "logic"; am clearly thinking about this with intent to understand.

I think you're both selling me on the 1650kv! Just a big drop in KV, so need to gear it up some. And concerned at that point I will lose run time compared to the 2200kv.

I care about runtimes too, because I like to hike while RC’ing and don’t want to take a lot of lipo’s with me.
I’m pretty happy with the Max6/4985 1650kv combo. As for lipo, I either run 9500mah 4s or 8000mah 6s.

 

[Exc3l]

Honestly, if you care about run times a lot, grab some 9000mah lipo's and take one with you.

 

[TL01magic]

Honestly, if you care about run times a lot, grab some 9000mah lipo's and take one with you.

I kinda feel like it's prudent before buying the gear to understand what am getting;

RE: just throwing mah at the run time concern.

First am considering efficiency; the consequence is runtime.
Second am planning on 3s packs so I can use em in my senton as well as the mojave. So 9000mah is nonsense solution to not wanting to waste battery powering an oversized motor.

That said it seems opinion is the 1717 is best for the mojave (compared to 1515).

15 minutes run time is normal. Give or take. Just have spare packs to change out. I hope you don't expect to drive your rig for 30min to an hour on one Lipo. You are stressing too much on run time. There are many other variable factors to consider. Like gearing and Lipo Mah and C ratings and ESC settings.

There will be runs where I get over 30min; I find it fun taking them on walking / bike trails.

But yea for bashing mojave's I figure 15min is common.

 

[SrC]

I hike with my Crawlers for a few miles easily on one pack or 2.
But we all bash differently with our fast basher rigs. I tried hiking with my Bashers. Not for me. They are tuned for speed. Not a walks pace.

 

[Exc3l]

That said it seems opinion is the 1717 is best for the mojave (compared to 1515).

You can't even run that 1515 on the Mojave. The Mojave is the longest car Arrma sells so it is not light at all. The Mojave is over 1lb heavier than a Kraton. Let's say you do get more runtime without changing batteries. Realistically how much more runtime do you think you are going to get from that?

 

[TL01magic]

I hike with my Crawlers for a few miles easily on one pack or 2.
But we all bash differently with our fast basher rigs. I tried hiking with my Bashers. Not for me. They are tuned for speed. Not a walks pace.

Ahaha; yea that gets to the point of getting a sensored set-up. I can lower gearing to better place speed to help further.

That said, I've not taken the mojave out yet (winter) and in past my RC trail walks were with a Wraith, obviously much better.

I'll see how 1/7 sct is trail walking RC; but am confident the platform can be worked with if stock is not fun for that use.

 

[Exc3l]

Ahaha; yea that gets to the point of getting a sensored set-up. I can lower gearing to better place speed to help further.

The lower you gear the average rpm of the motor will be higher. I recommend you turn down throttle percentage to get more run time.

 

[SrC]

@TL01magic,
I think you need a TRX4 Crawler now, with a 2 speed tranny and a sensored setup.
You have outgrown your current rig.

 

[TL01magic]

You can't even run that 1515 on the Mojave. The Mojave is the longest car Arrma sells so it is not light at all. The Mojave is over 1lb heavier than a Kraton. Let's say you do get more runtime without changing batteries. Realistically how much more runtime do you think you are going to get from that?

!! oh I though the 1515 was same sized motor as stock (4074 I think / but 2050 kv)

checking 1515 size now; hmm..it's a 4074 size, so same as stock but a bit more KV.

RE: diff in runtime expectation; that is my question. I guess if pressed for a guess I would say a range of 5 minutes difference possible. But do not know and why am asking. I'll ask Castle their recommendation in context of 40mph top speed for mojave.

I think you need a TRX4 Crawler now, with a 2 speed tranny and a sensored setup.
You have outgrown your current rig.

omg Yes I almost got one of those instead; is just that it's so perfect for trail / crawling it doesn't seem like a good basher too.

imo those are PERFECT for trail walking RC like am talking about.

 

[Sandracer_NL]

I hike with my Crawlers for a few miles easily on one pack or 2.
But we all bash differently with our fast basher rigs. I tried hiking with my Bashers. Not for me. They are tuned for speed. Not a walks pace.

The car only does walking pace from time to time. Although I am walking the car goes way faster than me ; more like medium to high(er) speed offroading. And a few spots during the hike are wide open.

 

[TL01magic]

The car only does walking pace from time to time. Although I am walking the car goes way faster than me ; more like medium to high(er) speed offroading. And a few spots during the hike are wide open.

Yea that's more inline with what am trying to describe.

just wanted to highlight the walking speed use. There are times a section of trail is perfect for ripping across, often sweeping turns I find most fun! lol

yes that use GREATLY changes run time; so left that out of my describing trail walking RC