Mojave 2650KV, 2200KV or 1800KV for XLWB Kraton/Mojave

[fish]

So what's the real world trade-offs between 2650KV, 2200KV and 1800KV motors.
Specifically Castle 1512's with a Monster X 25.2V ESC with 6S Lipo's.

Im running a Mojave exp chassis with Kraton Arms basically.
Ive been running mostly dBoots Back-Flip MT 6S at 172m X 97mm.
Im using Kraton F/R Open Difs and a Typhon BLX Open Center Dif (1m/cst) with a 50t Spur. 16, 18 and 20t pinions, about 15lbs.

Basic Math for maximum potential says:
(50t/20t, 4.3 difs, 10.75 final drive, 172mm tire diameter. 6S at 4.2 v/cell)

2650KV = 125.2mph (50t/20t)
2200KV = 103.9mph (50t/20t)
2050KV = 96.8mph (50t/20t) *stock
1800KV = 85.0mph (50t/20t)

2650KV = 112.6mph (50t/18t)
2200KV = 93.5mph (50t/18t)
2050KV = 87.1mph (50t/18t) *stock
1800KV = 76.5mph (50t/18t)

Im looking for Speed over rough terrain like Grass, dirt, some gravel and rocky dirt. Not allot of climbing or jumping.
Mostly running level fields and some parking lots and streets with different tires.
Im getting between 75-85 mph with 18/20 pinions. Depends on weather too.
The Firma 150 finally burned up - literally.

2200KV seems to be most popular.

2650KV seems more of what I want.


When I got into this Hobby, no one said their would be Math!

 

[Luke66]

Well buddy. Now you know what you're mommy was talking about when she said that you needed to learn math!

 

[fish]

Well buddy. Now you know what you're mommy was talking about when she said that you needed to learn math!

HA, the math was done by an app and my mother can hardly use a remote control, she's very old.


Does the 2650KV have enough torque and can it actually achieve high rpm's pushing this over-sized 6S Arrma?

Is a 2200KV enough or a better compromise?

A 1800KV with higher gearing?

I just don't know.




Monster X 25.2V ESC, w/1512-2650KV SENSORED Motor Combo
https://a.co/d/dU07UFN

Mamba X, 25.2V WP ESC w/ 1515-2200KV SENSORED Motor Combo
https://a.co/d/3BakhQL

Monster X 25.2V ESC w/1512-1800KV SENSORED Motor Combo
https://a.co/d/1ADR7ES

 

[Garcbomber]

You’re gonna need a big bore 1650 kv can and 8S ESC to sustain that gearing/tire OD on a 15+lb rig or you’ll end up with another burn down.

 

[RC Steve]

The 1512s are 3-4s motors made for buggy size/weight trucks. if you pump 6s through them, you'll cook them to death. The 1515 is a good 6s motor and can handle the weight of your truck. When looking at Castle motors scroll down and check the specs, Castle is good about stating any limits their motors may have.

 

[dure16]

Motor size is the primary indicator for power, and the Castle 1512 isn’t big enough for your truck.

1515 can handle it if you keep gearing conservative. 1520 would be better. But I’d do the 1717 for a heavy truck like that.

 

[fish]

Thanks, thats what im learning too...

This I likely fine:

w/ 1515-2200KV SENSORED Motor Combo
https://a.co/d/3BakhQL

 

[dure16]

Thanks, thats what im learning too...

This I likely fine:

w/ 1515-2200KV SENSORED Motor Combo
https://a.co/d/3BakhQL

Well, not for high speed grass runs like you said. I’d go bigger if that’s really your intent.

 

[Radiocontrolsoul]

I would not run that motor unless you want lots of heat

 

[fish]

Well, not for high speed grass runs like you said. I’d go bigger if that’s really your intent.

Recommend please.

1800? Not Castle?

 

[Moirae]

Recommend please.

1800? Not Castle?

the castle mmx8s 1717 1650kv combo is your best bet if you want castle in that truck. I have a castle mmx8s and tp 4070 1700kv in large buggy similar to yours and the castle 1717 combo in my fireteam. You can't go wrong with either but I love that mmx8s tp 4070 combo.

 

[dure16]

Recommend please.

1800? Not Castle?

MMX8S ESC
1717 1650kv motor

 

[fish]

the castle mmx8s 1717 1650kv combo is your best bet if you want castle in that truck. I have a castle mmx8s and tp 4070 1700kv in large buggy similar to yours and the castle 1717 combo in my fireteam. You can't go wrong with either but I love that mmx8s tp 4070 combo.

You guys are a big help, thanks. Also good at spending money, we all have that common LOL

I had my eye on this TP Motor
TP 4070-CM 2200KV (6-8S)
https://www.tppowerusa.com/index.php?route=product/product&path=20_135_149&product_id=402


Seems this ESC below is the Best Buy overall.
Its BIG! Will Hardly fit in the rig.
I use a Mojave chassis and sides which are tall, allows me to velcro the shell down.
It will just about fit.

Mamba Monster X 8S
1050 watts, 33.6 Volts, 8A BEC, (2-8S)
vehicle weighing up to 25 lbs
2.74" x 2.13" x 1.93"
5.75 oz. (163.g)
https://www.castlecreations.com/en/1-6th-scale/mamba-monster-x-8s-33-6v-esc-010-0165-00



About the KV of the motor.
The "Math" says the lower KV will result in lower mph potential.
A 50spur/20pinion isn't going to give me any extra speed with a 1650 +/- KV motor, right?

Yet a 2200KV with 6S or 8S should yield me significant better performance from the stock 2050KV at 6S.

No? Yes?

Im still trying to understand how or should I say why a 800KV-1600KV motor is beneficial.

 

[Moirae]

You guys are a big help, thanks. Also good at spending money, we all have that common LOL

I had my eye on this TP Motor
TP 4070-CM 2200KV (6-8S)
https://www.tppowerusa.com/index.php?route=product/product&path=20_135_149&product_id=402


Seems this ESC below is the Best Buy overall.
Its BIG! Will Hardly fit in the rig.
I use a Mojave chassis and sides which are tall, allows me to velcro the shell down.
It will just about fit.

Mamba Monster X 8S
1050 watts, 33.6 Volts, 8A BEC, (2-8S)
vehicle weighing up to 25 lbs
2.74" x 2.13" x 1.93"
5.75 oz. (163.g)
https://www.castlecreations.com/en/1-6th-scale/mamba-monster-x-8s-33-6v-esc-010-0165-00



About the KV of the motor.
The "Math" says the lower KV will result in lower mph potential.
A 50spur/20pinion isn't going to give me any extra speed with a 1650 +/- KV motor, right?

Yet a 2200KV with 6S or 8S should yield me significant better performance from the stock 2050KV at 6S.

No? Yes?

Im still trying to understand how or should I say why a 800KV-1600KV motor is beneficial.

I actually have that tp motor in an onroad rig! good motor but I dunno about putting it in a basher with big tires. I think it might run hot for that. That's also the big pro for going lower kv, lower kv should run cooler and you can always gear up to make up the speed.

It doesn't matter what type of speed boost you get from higher kv when you can just put on a bigger pinion or smaller spur. If I were you I'd definitely go for the 4070 1700kv, you can still reach the same speeds with a pinion swap and you can bash it without it getting as hot.

That 2200kv might also work out fine for you though tbh but personally I'd definitely go 1700kv

 

[SrC]

So what's the real world trade-offs between 2650KV, 2200KV and 1800KV motors.
Specifically Castle 1512's with a Monster X 25.2V ESC with 6S Lipo's.

Im running a Mojave exp chassis with Kraton Arms basically.
Ive been running mostly dBoots Back-Flip MT 6S at 172m X 97mm.
Im using Kraton F/R Open Difs and a Typhon BLX Open Center Dif (1m/cst) with a 50t Spur. 16, 18 and 20t pinions, about 15lbs.

Basic Math for maximum potential says:
(50t/20t, 4.3 difs, 10.75 final drive, 172mm tire diameter. 6S at 4.2 v/cell)

2650KV = 125.2mph (50t/20t)
2200KV = 103.9mph (50t/20t)
2050KV = 96.8mph (50t/20t) *stock
1800KV = 85.0mph (50t/20t)

2650KV = 112.6mph (50t/18t)
2200KV = 93.5mph (50t/18t)
2050KV = 87.1mph (50t/18t) *stock
1800KV = 76.5mph (50t/18t)

Im looking for Speed over rough terrain like Grass, dirt, some gravel and rocky dirt. Not allot of climbing or jumping.
Mostly running level fields and some parking lots and streets with different tires.
Im getting between 75-85 mph with 18/20 pinions. Depends on weather too.
The Firma 150 finally burned up - literally.

2200KV seems to be most popular.

2650KV seems more of what I want.


When I got into this Hobby, no one said their would be Math!

The math is only hypothetical. But a good rough idea for comparsion purposes. The math never calculates real actual load and torque.
I would go to 1700-1900 Kv and gear that better for a Heavy XLWB FT platform. Need a quality ESC. 8s level electrics IMHO for 6s running if you are so inclined to want a 6s setup . For the better Amp Overhead. Need the Good lipos for speed running.
And FWIW a stocker 2050 Kv Firma motor is actualy 1930 kv's, give or take. Never sees 2050kv's. When I test them on my BLX motor analyzer.
KV varies from brand to brand. Advertised specs are far from spot on. Some food for thought.
Many input the Lipo pack voltage at it's Nominal voltage value, to get a more conservative and actual realistic projected speed when using a Speed Gear calculator.

 

[dure16]

the castle mmx8s 1717 1650kv combo is your best bet if you want castle in that truck. I have a castle mmx8s and tp 4070 1700kv in large buggy similar to yours and the castle 1717 combo in my fireteam. You can't go wrong with either but I love that mmx8s tp 4070 combo.

What's better about the 4070 over the 1717?

 

[Moirae]

What's better about the 4070 over the 1717?

more power and higher quality.

 

[fish]

The math is only hypothetical. But a good rough idea for comparsion purposes. The math never calculates real actual load and torque.
I would go to 1700-1900 Kv and gear that better for a Heavy XLWB FT platform. Need a quality ESC. 8s level electrics IMHO for 6s running if you are so inclined to want a 6s setup . For the better Amp Overhead. Need the Good lipos for speed running.
And FWIW a stocker 2050 Kv Firma motor is actualy 1930 kv's, give or take. Never sees 2050kv's. When I test them on my BLX motor analyzer.
KV varies from brand to brand. Advertised specs are far from spot on. Some food for thought.
Many input the Lipo pack voltage at it's Nominal voltage value, to get a more conservative and actual realistic projected speed when using a Speed Gear calculator.

Oh I know, but it does help you calculate and compare.
Lots of other variables.

Rig weight will be about 6400g. (about 14 lbs) with a 6S 8000mAh Lipo and Back-Flip MT's. Thats about as heavy as it will get +/- 0.5lbs)

Not sure how much more torque I need. Kraton and Mojave are heavier by more than a few lbs. 8S kraton is much heavier still.
And their bodies introduce lots of drag to overcome.


I'll likely start off with the Mamba Monster X 8S ESC and beat the snot out of the stock 2050KV motor.

 

[SrC]

You might have better luck with dedicated Speed Running on that platform, if you go to a lighter and lower profile tire. Did you mean you are going with the 6s BF or the BF LP's???
Also, I would place the Lipo tray in its Forward most position, (stock setup) to keep the nose down and planted. While also turning the Punch Down. Don't need it or want it with Speed running. The Lipo tray forward will help greatly. The best I am getting with Stock Spekrum electrics on my All stock FT is 64MPH. (Speed gear) I set it up for just speed running, several months ago. With Belted Sweeps Terrain Crushers. For pavement only.
Now I moved the Lipo tray Rearward again, removed the T Crushers, upped the Punch back some and Bash in the dirt only.
For big air you need the lipo tray way back or it nose dives. Being nose heavy.
But with Speed running you need it forward to keep the nose down, because at speed it always wants to lift. This bleeds off speed when the front wheels lift. Need more weight up front for speed running.
What I noticed when I did this.

 

[fish]

You might have better luck with dedicated Speed Running on that platform, if you go to a lighter and lower profile tire. Did you mean you are going with the 6s BF or the BF LP's???
Also, I would place the Lipo tray in its Forward most position, (stock setup) to keep the nose down and planted. While also turning the Punch Down. Don't need it or want it with Speed running. The Lipo tray forward will help greatly. The best I am getting with Stock Spekrum electrics on my All stock FT is 64MPH. (Speed gear) I set it up for just speed running, several months ago. With Belted Sweeps Terrain Crushers. For pavement only.
Now I moved the Lipo tray Rearward again, removed the T Crushers, upped the Punch back some and Bash in the dirt only.
For big air you need the lipo tray way back or it nose dives. Being nose heavy.
But with Speed running you need it forward to keep the nose down, because at speed it always wants to lift. This bleeds off speed when the front wheels lift. Need more weight up front for speed running.
What I noticed when I did this.

Thanks, always good advice.

I think for his 14-15 lb extra long wheelbase, Kraton/Typhon runner this combo maybe a good next step on a rather Stock Arrma parts car.
And if it's not I have a stretched Typhon 6S that would love to have it! It's about 11-13 lbs with a Big 8000mAh battery.

Mamba Monster X 25.2V ESC with a 1515-2200Kv V2 Motor

Been watching YouTubes of people putting this Combo in Kraton's and other Arrma 6S rigs and it appears to kick the snot out of the stock Firma 150-185 ESCs with 2050KV motors they all come with. Faster and More Powerful than Stock.

Im also just thinking that the stock Arrma 6S EXB drivetrain in my 6S runners are going to crumble under the load of a 6S-8S with a 1520-1650KV motor thats meant for a Kraton 8S rig. Im not looking to drop $1k on upgrades for a 8S powered 6S rig. And Id actually like a 8S rig next so...

I enjoy trying to see just how much I can get from Stock parts to mild upgrades. Thats why ive avoided all the boutique parts for now. It's easy to fall in love with it and spend thousands on 1 beauty queen.

I also want a Limitless so maybe that will be my Next car. I can do a 8S Limitless.


You are right, ive gotten the bigger "Bad Wolf" to stay level over the rough fields. 1m cst in a Typhon center open diff helped with 500 front/back open difs from a Kraton. That longer Mojave chassis helped the most. And I'll be Damned, but those dBoots Back-Flip MT 6S at 172m just work for me! Not allot of ballooning, they stay solid and I get great speed with them over the Turf. Typhon towers, Kraton Shocks with heavier springs and oil weight.

I tired the Mojave tires and they are just too small. Buy I like them allot on my Stretched 6S Typhon. I have SO MANY tires now, duffle bags full LOL
I just tried the Talion EXB tires and they're just okay. The Back-Flip MT 6S's are working way better for me.

Stock 6S Kraton did about 40-45 mph on my grass fields.
As I modified and tuned them, they got faster and faster...till the fire. LOL

I found a combination of towers and shocks that are working nicely for me now.
With 18t pinion it was doing around 70-75mph.
With a 20t Ive broke into the 80's on a grass field. BTW the condition and weather can Vary speed by 10+ mph. So always looking for those perfect conditions.
I ran a 23t pinion and best times was mid/upper 80's and it was running WAY TO HOT. Blew a shaft and cup. SO Ive been staying with around 20t +/-
All stock Arrma parts. Cheap consumables. Thats what overheated the Firma 150 and caused the fire, I also think grass stoped-up the fan on the ESC.

Same rigs on pavement with street tires Ive been seeing as high as 90mph, one day I broke 100. 23t pinion on pavement. And Yeah, it was running Way Too hot. Just did 10 minute rips outside my house. 20t is better, also slower.

75+ mph over a sports field is actually Fast Enough for Fun!

Getting up to 100 mph on grass is just way difficult.

*EDIT I just read this from last year. LOL Yeah, thats where I left off.
https://www.arrmaforum.com/threads/...on-and-mojave-bits-n-pieces.53029/post-819399
Saw that Fire coming!

This is the one that Burned.

This is the other one.
That Firma 150 is Next to Burn! It gets SO HOT! 20-22t (80-90 mph on pavement)