Motor comparison question.

[biggman100]

Which would be better for a Losi TEN-SCTE that is only ran on 2S, a HW 3656 4700KV, or a HW 3665 3800KV? The reason I'm asking is because i already have the 3656 4700KV, and, i was planning on pairing it with a HW WP SC8, but, unless i am way beyond tired, and everything i read i read wrong, it seems like the 4700KV wont work in that truck to get any decent speed, at least, not on 2S. That truck came with a HW XeRun SCT Pro and 4274 2200KV, which i stuck in a Slash 4X4 while i rebuild the TEN-SCTE, and, on 2S, it gets decent speed, but, the battery dies in about 9 minutes, which just seems like its way too quick, and, i just dont want to spend the money only to run into the same problem over again.

Totally separate question, but, would going with a bigger pinion on the Slash 4X4 help in any way with the short run times? The battery i am using is a 5200MAH 50C, so, maybe that is part of the issue as well.

 

[KnowAir]

I looked up the 3656 4700 on Amain, they're calling it an sct motor, with 4x4 as the best application. 4700kv would be best suited to a 2s battery. Actually, I think it would likely overheat on 3s rather easily. This would be my choice for 2s in an sct.
The 3800 is gonna be somewhat slow on 2s I think, perhaps with enough gear you can get decent speeds but, it really wants 3s IMO.
As to the 4274 in the slash, thats all wrong for 2s..that's an 1/8 truggy motor best suited for 4s.
I bet if you at least up the battery to 3s, you'll see vast improvement in run time and speed. Even still, it's a 4s motor for an 8-10lb truggy, not a slash. The slash vxl comes with a 3500kv 3660, and flat out rips on 3s, to get more speed on 2s, I'd be looking at 4400kv and up. Good luck, and happy bashing brother!

 

[bill_delong]

So many things to address:

1) You did not specify what your needs are... speed runs? If so then what speed?
2) Yes a HW 3656 4700KV will work perfectly fine in a SCTE and should net speeds in the 35-40mph range, acceleration won't be nearly as aggressive as the 4274 motor which is designed for a 1/8 Truggy... NOT a 1/10 SCT
3) If you want an optimal setup, then I would recommend a 3660 1800KV motor on 4S, I was able to complete a 20 min race with this setup on my TEKNO SCT410.3, more info here:
https://www.teknoforums.com/threads/build-review-sct410-3.1389/post-22242

2S limitation for SCT's is a dated rule from ROAR that has effectively killed the class because modern SCT's are based on 1/8 buggies which cook the electronics. If you want to save money over the long haul with a far more efficient setup with cooler temps and longer run times, then go 3660 1800KV on 4S, your wallet will thank you

***UPDATE***
Side note, I also suspect your gearing may not be correct either, I would encourage you to invest in a temp gun and check your gearing with the following guideline:
https://www.rcgroups.com/forums/sho...eed-to-run-for-upgraded-electronics-in-my-car

 

[KnowAir]

So many things to address:

1) You did not specify what your needs are... speed runs? If so then what speed?
2) Yes a HW 3656 4700KV will work perfectly fine in a SCTE and should net speeds in the 35-40mph range, acceleration won't be nearly as aggressive as the 4274 motor which is designed for a 1/8 Truggy... NOT a 1/10 SCT
3) If you want an optimal setup, then I would recommend a 3660 1800KV motor on 4S, I was able to complete a 20 min race with this setup on my TEKNO SCT410.3, more info here:
https://www.teknoforums.com/threads/build-review-sct410-3.1389/post-22242

2S limitation for SCT's is a dated rule from ROAR that has effectively killed the class because modern SCT's are based on 1/8 buggies which cook the electronics. If you want to save money over the long haul with a far more efficient setup with cooler temps and longer run times, then go 3660 1800KV on 4S, your wallet will thank you

3660 or 3670? I found nothing but boat motors when searching a 3660 1800kv? I have read many of your threads here and over on Tekno forum. Much thanks and respect for your knowledge and help
4s sct sounds heavy? I guess that'll depend on amp hours though. I did try my 410.3 on 4s with a 3670, I found it to be a bit of a pig. 3s is the sweet spot for me in my setting, which is a backyard track.

 

[bill_delong]

Since you want a little more speed then I would recommend the following 3665 - 2100KV motor for your application, maybe start with a 18T pinion and check temps, it might do better with a 17T pinion because I ran 18T with the 1800KV:
https://www.rcjuice.com/motor-esc/b...le-brushless-sensorless-motor-waterproof.html

I would also recommend a 4S LCG pack, something like this here would be perfect:
https://www.amazon.com/gp/product/B09CMHWHLL/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[biggman100]

So many things to address:

1) You did not specify what your needs are... speed runs? If so then what speed?
2) Yes a HW 3656 4700KV will work perfectly fine in a SCTE and should net speeds in the 35-40mph range, acceleration won't be nearly as aggressive as the 4274 motor which is designed for a 1/8 Truggy... NOT a 1/10 SCT
3) If you want an optimal setup, then I would recommend a 3660 1800KV motor on 4S, I was able to complete a 20 min race with this setup on my TEKNO SCT410.3, more info here:
https://www.teknoforums.com/threads/build-review-sct410-3.1389/post-22242

2S limitation for SCT's is a dated rule from ROAR that has effectively killed the class because modern SCT's are based on 1/8 buggies which cook the electronics. If you want to save money over the long haul with a far more efficient setup with cooler temps and longer run times, then go 3660 1800KV on 4S, your wallet will thank you

***UPDATE***
Side note, I also suspect your gearing may not be correct either, I would encourage you to invest in a temp gun and check your gearing with the following guideline:
https://www.rcgroups.com/forums/sho...eed-to-run-for-upgraded-electronics-in-my-car

I dont race or do speed runs. My RC running consists entirely of bashing in fields and at a local skate park. Most people already know that my trucks see a lot of air. I only run 2S, so, i am looking for something that will work for that. I already have a temp gun, and i do check temps quite often, especially with how hard i run my stuff. As for the 4274, it came with the TEN-SCTE when i got it, but, after talking to a guy i bash with, we might be swapping my 4274 for one of his 3660 motors.

 

[bill_delong]

... I only run 2S, so, i am looking for something that will work for that....

and this is why you are going to be disappointed with anything you attempt to do... good luck with that

A compromise will be 3S on 3660-3200KV .... I ran that for a while which was better than 2S on 3660-4000KV but 4S on 3660-2000KV will be optimal

#beentheredonethat

 

[biggman100]

and this is why you are going to be disappointed with anything you attempt to do... good luck with that

I am never disappointed in anything i do. I run 2S in everything i own (strictly 1/10TH scale), and am more than happy with how they run. This one only came about because of the low run time mainly.

 

[bill_delong]

...but, the battery dies in about 9 minutes, which just seems like its way too quick, and, i just dont want to spend the money only to run into the same problem over again...

This is a typical run time for 2S which is grossly inefficient by wasting a ton of energy on heat which also puts unnecessary strain on the battery causing it to degrade faster.

The solution is to double the voltage and cut the KV in half which in turn cuts the current draw in half which reduces heat and increases run time and extends battery longevity.

I'm going to stop beating the dead horse, but at least you now know the limitations you have put yourself into and what to expect, best of luck!

 

[biggman100]

This is a typical run time for 2S which is grossly inefficient by wasting a ton of energy on heat which also puts unnecessary strain on the battery causing it to degrade faster.

The solution is to double the voltage and cut the KV in half which in turn cuts the current draw in half which reduces heat and increases run time and extends battery longevity.

I'm going to stop beating the dead horse, but at least you now know the limitations you have put yourself into and what to expect, best of luck!

This is the only truck i have ever experienced this with, which is why i asked about it in the first place, but, the first reply told me pretty much what i suspected was the issue. The motor that is currently in it is apparently too much for 2S, so, i will put the 4700KV i have in it, and see what happens. It also tells me i should stay away from big motors all together, which is perfectly ok with me.

 

[bill_delong]

just to clarify... you're comparing the SCTE which is based on a 1/8 buggy platform which weighs close to 8 pounds to a 4WD Slash which is a true 1/10 platform that weighs nearly half as much as the SCTE.... if so, then it's comparing apples to oranges.

Side note, TEKNO recently released the SCT410SL where SL stands for "Super Light" where it's based on the ET410 which is a true 1/10 based platform that should be ran on 2S. Only problem with these lighter 1/10 platforms are they are weaker and are more likely to break. Not saying the new SL from TEKNO is as fragile at the Slash, but it's no where near as durable as the .3 which was discontinued where the .3 was comparable to the SCTE.

Any 1/8 based platform should be ran on 4S where true 1/10 platforms should be ran on 2S.

The problem is that ROAR made a rule that all 1/10 SCT's were required to run on 2S but the rule should've limited to 3660 can motors instead where a 1/8 buggy motor is a 4268 can and that should not be put into a 4WD SCT... and a 4274 can is gross overkill for a SCT, ha!

 

[KnowAir]

I definitely agree and recognize that doubling voltage will cut amp draw and the heat generated by it. Might be the way to go for some, my recommendation was based on using what the OP already had on hand with 2s and the 4700kv motor. Personally, I like 3s in a heavyweight, 2s in lightweight 1/10. My emphasis is more focused on weight and handling.
The fact that I can double up on my 2 and 3s batteries in my 1/8 scales makes my decision even more sensible for me. Win win if you will.

 

[biggman100]

just to clarify... you're comparing the SCTE which is based on a 1/8 buggy platform which weighs close to 8 pounds to a 4WD Slash which is a true 1/10 platform that weighs nearly half as much as the SCTE.... if so, then it's comparing apples to oranges.

Side note, TEKNO recently released the SCT410SL where SL stands for "Super Light" where it's based on the ET410 which is a true 1/10 based platform that should be ran on 2S. Only problem with these lighter 1/10 platforms are they are weaker and are more likely to break. Not saying the new SL from TEKNO is as fragile at the Slash, but it's no where near as durable as the .3 which was discontinued where the .3 was comparable to the SCTE.

Any 1/8 based platform should be ran on 4S where true 1/10 platforms should be ran on 2S.

The problem is that ROAR made a rule that all 1/10 SCT's were required to run on 2S but the rule should've limited to 3660 can motors instead where a 1/8 buggy motor is a 4268 can and that should not be put into a 4WD SCT... and a 4274 can is gross overkill for a SCT, ha!

I definitely agree and recognize that doubling voltage will cut amp draw and the heat generated by it. Might be the way to go for some, my recommendation was based on using what the OP already had on hand with 2s and the 4700kv motor. Personally, I like 3s in a heavyweight, 2s in lightweight 1/10. My emphasis is more focused on weight and handling.
The fact that I can double up on my 2 and 3s batteries in my 1/8 scales makes my decision even more sensible for me. Win win if you will.

I hope it doesn't seem like I'm disputing any of this, because I'm actually not trying to. When i got the TEN_SCTE (which i actually didnt pay anything for really. It came in a box of stuff a guy gave me for helping him clean out 3 separate sheds), which i literally know nothing about, it came with several different options for ESC and motor (XeRun SCT Pro and 4274 2200KV, 10BL120 and 4700KV 3656 (it actually came with 3 brand new sealed 10BL120's, which i used in other cars i have), (2) WP SC8's, and a couple other ESC's and motors in zip-loc bags), but, since it needs a ton of little parts (end links, bearings, spur, screws, both center driveshafts, and i can't even remember what else. Its currently stripped and in a box), i figured, since after all the upgrades, and since it is running Arrma Katar MT's from the Vorteks, i would see what different motor and ESC combo's worked and didnt work in my 4X4 Slash, which most did, except the 4274 setup thats in it now, and, since the 3656 needs new connectors, or at the very least, wires soldered on it, i would ask about it before i went through all the trouble of getting it ready. However, what i am probably going to do is sell the SCTE and the 4274 to a guy i know, and just use the XeRun SCT Pro and 3656 in my Slash or my Arrma SCT/truggy hybrid project. As for the whole 2S thing, after losing everything in a fire last year that may or may not have been caused by lipo's, I'm still extremely leery of them, so, i am limiting my lipo collection to 4 5200MAH 50C batteries for now. I have never owned anything more than 2S or the 2 3S i bought when i bought a 3S truck last year, because, everything i have ever owned is 1/10TH, and, after running a few friends 4S and 6S stuff, me personally, I'm not a fan of them.

 

[KnowAir]

@bill_delong You've definitely peaked my interest about upping voltage from 3 to 4s in my 410.3.. darned you!!
Currently running max 10 120a, 3670 2600kv on 3s (5.2ah)with 20t pinion and stock spur with Jconcepts choppers.. it actually runs so well, it's hard to justify changing it up.. hottest I've seen was 110f..but the gears in my mind are now turning...should I bother?
Not 4s with the 2600kv, but rather say the 1800kv, which I'd have to buy..

 

[bill_delong]

@bill_delong You've definitely peaked my interest about upping voltage from 3 to 4s in my 410.3.. darned you!!
Currently running max 10 120a, 3670 2600kv on 3s (5.2ah)with 20t pinion and stock spur with Jconcepts choppers.. it actually runs so well, it's hard to justify changing it up.. hottest I've seen was 110f..but the gears in my mind are now turning...should I bother?
Not 4s with the 2600kv, but rather say the 1800kv, which I'd have to buy..

Those are great temps with that setup!

Doesn't sound like it will be worth the upgrade to me... what I did was wait until it was time to replace my 3S pack before I decided to go 4S, the HobbyStar motors are inexpensive enough to make it worth the upgrade in my case, but I was overheating my electronics in abusive racing conditions which is why 4S made sense for me to improve efficiency.

 

[KnowAir]

Those are great temps with that setup!

Doesn't sound like it will be worth the upgrade to me... what I did was wait until it was time to replace my 3S pack before I decided to go 4S, the HobbyStar motors are inexpensive enough to make it worth the upgrade in my case, but I was overheating my electronics in abusive racing conditions which is why 4S made sense for me to improve efficiency.

Thanks for the reply. I think there's better places to spend for me right now. Thanks for talking me off the ledge, LOL.
The seed is planted though, so if/when something changes with my current setup, I'll likely give the 4s a go. Cheers!

 

[Sixtysixdeuce]

2S limitation for SCT's is a dated rule from ROAR that has effectively killed the class because modern SCT's are based on 1/8 buggies which cook the electronics. If you want to save money over the long haul with a far more efficient setup with cooler temps and longer run times, then go 3660 1800KV on 4S, your wallet will thank you

At 6.3 pounds dry, the TEN-SCTE isn't ROAR legal even with 2S unless you find a way to trim over a pound off it.

Almost a decade ago, I built a brushless SCT on a decked out Tamiya 801x. It's purpose-seek and destroy when little turds would start bashing with their Traxxas slashes while the rest of us were trying to tune 1/10 buggies and STs on the prepped indoor clay track. Yeah, there's a reason for the weight and voltage limit; that nearly 9 pound kit with a 2,600 kv 4274 on 4S turned the other SCTs into bowling pins.

 

[bill_delong]

At 6.3 pounds dry, the TEN-SCTE isn't ROAR legal even with 2S unless you find a way to trim over a pound off it.

Almost a decade ago, I built a brushless SCT on a decked out Tamiya 801x. It's purpose-seek and destroy when little turds would start bashing with their Traxxas slashes while the rest of us were trying to tune 1/10 buggies and STs on the prepped indoor clay track. Yeah, there's a reason for the weight and voltage limit; that nearly 9 pound kit with a 2,600 kv 4274 on 4S turned the other SCTs into bowling pins.

where are you getting your information on max weight?

I don't see anything other than a min weight restriction posted here:
https://www.roarracing.com/downloads/ROAR_Rule_Book.pdf

 

[biggman100]

At 6.3 pounds dry, the TEN-SCTE isn't ROAR legal even with 2S unless you find a way to trim over a pound off it.

Almost a decade ago, I built a brushless SCT on a decked out Tamiya 801x. It's purpose-seek and destroy when little turds would start bashing with their Traxxas slashes while the rest of us were trying to tune 1/10 buggies and STs on the prepped indoor clay track. Yeah, there's a reason for the weight and voltage limit; that nearly 9 pound kit with a 2,600 kv 4274 on 4S turned the other SCTs into bowling pins.

I'm not looking to race, just bash, so, race rules wont apply to me. I changed this all up though. I was gonna sell the TEN-SCTE, and find another 4WD, but, decided instead to keep the TEN-SCTE, trade the 4274 i have for either a 3652SL, or 3656, and run it on 2S, but, before i do any of that, now I'm on a hunt for what HW waterproof ESC will work with the 3656 4700KV i already have, since, today, in a Slash 4X4, a 2S 5200MAH 50C battery lasted all of maybe 10 minutes, and the XeRun SCT Pro ESC i have was almost 200 degrees F, so, I'm figuring the ESC, since the caps are rusty, is getting ready to die on me, and, stupidly, i sold both of the WP-SC8's i had, because i figured i would never use them.

 

[Sixtysixdeuce]

where are you getting your information on max weight?

I don't see anything other than a min weight restriction posted here:
https://www.roarracing.com/downloads/ROAR_Rule_Book.pdf

View attachment 165875

I seemed to recall 5.8 lbs being the max, but evidently I'm mistaken and there isn't one. Been awhile since I looked at SCT stuff, never really cared for them.

But in that vein, yeah, running a 6.5+ lb rig on ROAR-legal 2S power ain't gonna win squat when everybody else is 2 lbs lighter. Unless I guess one were to get a big mAh 2S and figure out how to keep things cool being geared to the moon or with a high KV motor under that load.