Limitless Dual Motor Speed Build

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jryanfallon

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Arrma RC's
  1. Fury
Hey Everyone,

I built a slash 4x4 that was powered by a TP 4070 and XLX2. So have some knowledge on speed builds after flipping that car after a PB of 104mph.

Got my hands on a limitless and ordered the Perfect Pass Chassis and M2C dual motor mount. I am planning on running 2 XLX2’s just wondering what pair of motors I should go with?

Any suggestion?
 
What voltage?
What are your speed goals?
Will it be a dedicated speed runner (no bashing)?
 
What voltage?
What are your speed goals?
Will it be a dedicated speed runner (no bashing)?
I only ever ran my slash on 6s. Had 8s batteries but left them charged and they puffed up.

I was thinking of starting with 12s and see how it’s goes.

Like to do speeds 150+

And 100% for speed, no bashing
 
Go to Forums , Arrma parts, speed demons, on this forum. You will get knowledge from the speed guys there. 🏁 🏁🏁💥.I am not into speed runs. But I do like quick. You will find help from them. Have fun. And welcome to the fastest Rc site around. These cars go Fastttttt. :LOL:. 🏁.
 
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I only ever ran my slash on 6s. Had 8s batteries but left them charged and they puffed up.

I was thinking of starting with 12s and see how it’s goes.

Like to do speeds 150+

And 100% for speed, no bashing
I’d go TP 4070CM or Castle 1721 2400kv.
 
I’d go TP 4070CM or Castle 1721 2400kv.
I have the TP in my slash, great motor. Should u get the 5 or 8 mm shaft and does open or sealed in matter?

I would think open would left heat out?
 
I have the TP in my slash, great motor. Should u get the 5 or 8 mm shaft and does open or sealed in matter?

I would think open would left heat out?
8mm shaft is always better. Stronger.

I would agree that open probably dissipates heat a little better, but I prefer sealed cans. I don’t want to worry about dirt and cleaning them. Even in a speed runner.
 
Hey Guys,

Watch James Mccoy’s video about using a receiver pack.


Are you just pulling the power out of all the esc’s and the plug in the receiver battery first?

Also, does it matter what slot/number you plug it into?
 
I only ever ran my slash on 6s. Had 8s batteries but left them charged and they puffed up.

I was thinking of starting with 12s and see how it’s goes.

Like to do speeds 150+

And 100% for speed, no bashing
The XLX2 is not a 12s ESC. You’d be limited to dual 8s motors. (Still 8s, does not make it 16s.)
Hey Guys,

Watch James Mccoy’s video about using a receiver pack.


Are you just pulling the power out of all the esc’s and the plug in the receiver battery first?

Also, does it matter what slot/number you plug it into?
The red power wire of each ESC receiver cable must be removed. Then your dedicated receiver pack can be plugged into any channel. You should get a pack that has dual Futaba style connectors, as each individual one has about a 5 amp limit. Two leads would get you ten amps available, safely.
 
The XLX2 is not a 12s ESC. You’d be limited to dual 8s motors. (Still 8s, does not make it 16s.)

The red power wire of each ESC receiver cable must be removed. Then your dedicated receiver pack can be plugged into any channel. You should get a pack that has dual Futaba style connectors, as each individual one has about a 5 amp limit. Two leads would get you ten amps available, safely.
Would BEC be better than a battery pack?
 
Would BEC be better than a battery pack?
No. But it’s a close second. People smarter than me explain that battery voltage is the cleanest voltage to power your servo. Lights don’t really matter.
An ESC’s BEC voltage is the “dirtiest” with a UBEC being better, but still a digital source that doesn’t supply a clean voltage.
There really isn’t a downside to powering your receiver with a dedicated pack. Especially since the batteries (LiIon would be my choice) are so small.
 
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Hey Everyone,

I built a slash 4x4 that was powered by a TP 4070 and XLX2. So have some knowledge on speed builds after flipping that car after a PB of 104mph.

Got my hands on a limitless and ordered the Perfect Pass Chassis and M2C dual motor mount. I am planning on running 2 XLX2’s just wondering what pair of motors I should go with?

Any suggestion?

TP4070 2200kv is sort of the default goto motor.
That is a great starting place.

With dual motors I have seen guys run over 160 mph on just 4s for each side.
I highly recommend starting lower voltage till you get above 140 mph, then consider increasing the power.

(Not trying to sound rude) As it is the dual motor car is going to be too much for your experience level. You really want to work your way up in speed. There is turning and learning that comes with each new boundary. Going 90-115 is one thing but 140+ the experience and forces on the car are completely different. It changes again around 160+ and again at 175+

GIF by Star Wars
 
TP4070 2200kv is sort of the default goto motor.
That is a great starting place.

With dual motors I have seen guys run over 160 mph on just 4s for each side.
I highly recommend starting lower voltage till you get above 140 mph, then consider increasing the power.

(Not trying to sound rude) As it is the dual motor car is going to be too much for your experience level. You really want to work your way up in speed. There is turning and learning that comes with each new boundary. Going 90-115 is one thing but 140+ the experience and forces on the car are completely different. It changes again around 160+ and again at 175+

GIF by Star Wars
Thanks for the advice - I am not planning on jumping right into 8S. But I just don’t want to build the car for 4S (even 3S) and then have to re purchase additional motors, etc.

There was a big jump from 80 to 104 tbh.

For the motors I been back and forth between these two

TP 4080-CM (2350KV, 8S)

And

TP 4070-SCM (2950KV, 8S)


Any suggestion on which motor to pick?
 
Thanks for the advice - I am not planning on jumping right into 8S. But I just don’t want to build the car for 4S (even 3S) and then have to re purchase additional motors, etc.

There was a big jump from 80 to 104 tbh.

For the motors I been back and forth between these two

TP 4080-CM (2350KV, 8S)

And

TP 4070-SCM (2950KV, 8S)


Any suggestion on which motor to pick?
Go with the 4080 cm (2350)
The scm motors are 2 pole and don't do as well in my opinion.
 
Late to the thread. My first speed car was (is) a dual 1721 2400kv. It has a few unique things about it.
Car will *easily* do 150 on 4s per side.
That said, a single motor 2028 1700kv GT car is going to be capable of 190 on 8s when its set up right. I think Raz pulled a 196 with a single 2028 1700 in an open wheel, but thats with overcharged and heated batteries.
If it were me, I'd go straight to dual 2028 1700's. If you go with castle motors. I can't speak to TP's, I haven't run any yet.
The 1721 2400s seem to start to have problems toward the 200mph line because of the RPM and how speed controllers work. Raz kept frying motors. So my car has a few tricks to get around that. But if they were out when I'd built mine, I'd have just gone straight to the 2028.
 
The XLX2 is not a 12s ESC. You’d be limited to dual 8s motors. (Still 8s, does not make it 16s.)
I've always wondered why it's not considered double the voltage. In tractor pulls and other things that have multiple engines, they always combine the HP #. If I had a car with two 300hp engines, I would claim 600 all day. I get that anything dual motor is in it's own class anyway so it doesn't really mater but it's always seemed strange. Have you heard other good explanations or arguments for either pint of view?
 
I've always wondered why it's not considered double the voltage. In tractor pulls and other things that have multiple engines, they always combine the HP #. If I had a car with two 300hp engines, I would claim 600 all day. I get that anything dual motor is in its own class anyway so it doesn't really mater but it's always seemed strange. Have you heard other good explanations or arguments for either pint of view?
It’s pretty much always stated as how much voltage each individual motor is running on. If it were stated in horsepower (which can be calculated) it might be a different conversation? It seems like then you would count the total hp powering the car, like you said.
But for now you could have six motors running 8s and the car would still be described as running 8s, not 48s. It would be said the car ran on 29.2 volts not 233 volts.
Don't know who accepted that standard…
 
I've always wondered why it's not considered double the voltage. In tractor pulls and other things that have multiple engines, they always combine the HP #. If I had a car with two 300hp engines, I would claim 600 all day. I get that anything dual motor is in it's own class anyway so it doesn't really mater but it's always seemed strange. Have you heard other good explanations or arguments for either pint of view?
I would totally add the power ratings as well. If each motor pushed 10,000 watts then we could call it a 20,000 watt car.

For this type of argument, I view volts kind of like octane. Higher octane gas has the potential to produce more power but there are other dependent factors as well. And if a car had two engines running 100 octane, you wouldn’t say the car was running on 200 octane.

It’s definitely not a perfect analogy though.
 
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