Limitless Best way to cool a 1:5 motor for speedruns.

[amdgobrrr]

I am planning some pretty big upgrades for my arrma limitless, some being a carbon fiber chassis upgrade, motor mounts, driveshaft stuff and a new motor to handle 8s. I’m planning to get the hobbywing 800kv 1:5 motor with the max5 v3 esc alongside it. What would be the best way to cool this so i can get a a fair amount of runs before having to give it a cooldown. Thanks in advance for any help.

 

[AIan]

if you plan on doing some serious speed running you might want to read up on castle creation esc for speeds over 100mph. I hear that Hobbywing can’t or doesn’t go much faster. Theres a lot of posts in the speed running section of the build threads here in the forum.
but big high rpm 40x40x28mm fans are great.
I use a couple of these on a couple of my rigs

 

[amdgobrrr]

Is it just the esc thats the problem or the motor too? Because i can’t quite stomach the price of the 800kv motor/esc castle provides yet, maybe if i wait a bit longer i could get some funds up for it.

 

[AIan]

it’s the esc that is what limits the Hobbywing combo some people use all different motors with the castle esc’s. I’m using a castle xlx2 with a couple different motors this year to learn my way into higher speed. I am starting with a surpass rocket 1420kv 4092 motor

and then I have a
Hobbywing 4985 1650kv motor I want to try
those before investing hundreds on castle or tp motors

but that’s just me, others may have better ways than me, I’m learning as I go

 

[rccar4life]

I did a budget system that works great

Sky rc 1/5 dual fan on motor 13bucks only for big 56mm motors

Then i remove the stock 40mm fans and mount two Powerhobby highspeed 40mm fans
highvoltage

Im very happy, cheap and works great.
I have same fans in many other cars, Powerhobby they run for ever.
Great quality , cheap

these Powerhobby have many names, same thing different brands. Rebrands

Surpass/Rocket/Powerhobby/Corally and couple more brands, all same
Have many of them 30mm and 40mm.

Stock fans last only 10-20 runs for me.
These aluminium highspeed fans have last more than 50 runs in other cars i have.
No issues, they are Great

 

[Moirae]

With 2x 12v fans I can bash my limitless with 30/40 gearing.

 

[rotauq]

I'd spend my money on a high-end motor before getting a carbon chassis... Learn to deal with the speed before you start crashing expensive parts. Motors more often survive whiles chassis don't.

800KV will push you towards big gearing. I would advice 1100-14xx KV and GP5 diffs (2.8 ratio instead of 3.307)
With a XLX2 esc (and decent batteries) you can push any motor to it's limits, i would also just start with a cheap 4092 (good for 125+mph) before you throw in a 56 torque monster.

 

[rccar4life]

yes,. one 1100kv is better to rigs with small 98-101mm wheels , 1/7 arrma speedcars , limitless/infraction/felony

800kv 113 is more for 1/5 cars like the Kraton 8s, heavy cars

1100kv is shorter can, and perfect to 1/7 speedrun cars.
You want more KV,s in pure speedrun cars.

Huge heavy 1/5 rigs with mega big 200mm wheels you want long 113mm 800kv 56 motor in

i have 8s Kraton 49size stock 1250kv in my limitless, run it 8s, cheap and great workhorse, runs cool, needs only one fan
motor is made for heavy 1/5 rig
check this out
https://jennysrc.com/products/krato...-firma-spektrum-spmxsm1205-arrma-1-5-ar110002
this fits in stock motor mount also.
Very fast and powerfull, i run 27-30t pinions and 29t spool https://www.amainhobbies.com/arrma-...ar-w-8mm-bore-29t-ara310950/p1173554?v=981285
stock is 34 i believe , 29t makes it faster and the 1250 firma motor has alot torque also , set esc setting to max punch

 

[SrC]

I am planning some pretty big upgrades for my arrma limitless, some being a carbon fiber chassis upgrade, motor mounts, driveshaft stuff and a new motor to handle 8s. I’m planning to get the hobbywing 800kv 1:5 motor with the max5 v3 esc alongside it. What would be the best way to cool this so i can get a a fair amount of runs before having to give it a cooldown. Thanks in advance for any help.

You always do cool downs between passes if you are investing all this into Serious Dedicated speed running. No such thing as a "fair amount of runs between cool downs". Cool downs needed between Every single pass. Temp gun in hand after every pass till you are comfortable with temps.

I imagine an 800kv motor won't be running hot for the most part. For speed runs, probably not the best pick. Do you need all that Torque with the Lim anyway??
Get yourself a Temp Gun if you don't have one, to evaluate what temps you will be actually getting.
If anything, 40mm fan(s) blowing directly at the motor will be best.
Using No HS at all.

 

[amdgobrrr]

Ok, so what i’ve changed so far is:

1100kv - 1250kv motor instead of 800.
Get an xlx2 esc so i can run pretty much any motor.
Scratch the carbon fibre chassis for now.
Get some gp5 diffs.
Cooling-wise some decent quality 40mm fans should do.
Get a temp gun.

 

[rccar4life]

if you are running 8s , go with 1250kv motor

if you want INSANE speeds LIKE INSANE then go Castle 1650kv 8s motor or TP

I have 1250kv for both speedruns and bashing, i have run more than 60x 6200mah in my first limitless with max6 and 1250kv 8s spektrum motor
WORKHORSE. no fails
The 1250kv SPEKTRUM can handle 180 amps, so Monster X atleast would be great for pure speedruns.
i run it 160a MAX6 and love it
cool and super fast, alot torque also, drift like a king if you like also

 

[SrC]

Ok, so what i’ve changed so far is:

1100kv - 1250kv motor instead of 800.
Get an xlx2 esc so i can run pretty much any motor.
Scratch the carbon fibre chassis for now.
Get some gp5 diffs.
Cooling-wise some decent quality 40mm fans should do.
Get a temp gun.

+1.
Sounds like a good plan.

 

[amdgobrrr]

One last question, could anybody recommend any high discharge 4s batteries, preferably with xt60/90 connectors

 

[Moirae]

One last question, could anybody recommend any high discharge 4s batteries, preferably with xt60/90 connectors

These are really good imo and xt90

 

[rotauq]

One last question, could anybody recommend any high discharge 4s batteries, preferably with xt60/90 connectors

With 1/5 scale motors in mind high discharge certainly does not go well with xt60 and xt90 only to a certain point. In my experience xt90 can take about 7kW before they start melting.
Propper speedrunning asks for 8AWG cables and 8mm connectors. SMC and CNHL have several options available.

 

[jondilly1974]

I am planning some pretty big upgrades for my arrma limitless, some being a carbon fiber chassis upgrade, motor mounts, driveshaft stuff and a new motor to handle 8s. I’m planning to get the hobbywing 800kv 1:5 motor with the max5 v3 esc alongside it. What would be the best way to cool this so i can get a a fair amount of runs before having to give it a cooldown. Thanks in advance for any help.

Best off not using that setup at all. A MAX5 won’t get you much past 100mph. You’ll want an XLX2 and a TP56/58 series motor for serious speed runs. And heat shouldn’t be a factor on a single pass anyways.

Just one pass, everybody knows the rules.

 

[amdgobrrr]

Best off not using that setup at all. A MAX5 won’t get you much past 100mph. You’ll want an XLX2 and a TP56/58 series motor for serious speed runs. And heat shouldn’t be a factor on a single pass anyways.

Just one pass, everybody knows the rules.

Ok, so what i’ve changed so far is:

1100kv - 1250kv motor instead of 800.
Get an xlx2 esc so i can run pretty much any motor.
Scratch the carbon fibre chassis for now.
Get some gp5 diffs.
Cooling-wise some decent quality 40mm fans should do.
Get a temp gun

I’ve changed a few things, and i’ve also decided to get a 56xx tp motor.