Selecting Correct Gearing for a Beast of a Motor - Castle 1721 2400Kv

[@tkostang]

You do realize that this esc/motor combo is good for over 100 mph on 3s, right?

[@BrianW2979]

There is an app called gear speed that will do these calculations also.

[@colin1992]

Excited!

[@tonydstroman]

Hey I am new to this data on how to figure out how fast car can go. I have a arrma infraction with a 2650 motor and 26 piñon gear. How to I find out how fast to calculate the speed?

[@lifeisgood7377]

Thanks for the informative video. I just got a Limitless. What set up would you recommend for 6s drag racing?

[@jeffsmith1580]

Hi Ryan! Great video as always😀 Just wondering when you calculate HP of your RC car should you use the voltage of your lipo fully charged, so 16.8v for me (4s) or should I use the nominal voltage or something along the lines of that. (Keep in mind that I am using a battery that can discharge 600amps continusoly in a system that will not draw over 400amps peak so there shouldn't be much of a voltage drop, if that matters😀)

[@RCexplained]

Use the voltage and current from the data log of a run. Then multiply by the expected efficiency.

[@darrickburke5093]

I don't understand why u think it can even be mounted in the stock formation of the limitless how will it fit?

[@letzvisit1661]

Just got a v2 limitless any ideas on a good value motor and the right gearing and esc that won’t break the bank. I want to be able to run the car around a bit at slow speeds for testing and fun and then attempt speed runs up to around 120 ish mph any ideas? Thanks

[@isaackshirley4695]

How did you fit the motor in I was trying to find the video that u fitting the 1721 2400kv motor in I saw u eliminated the battery tray idk what else do you have a video showing how😅

[@RCexplained]

On the v1 I rotated the motor mount 180 degrees.

[@isaackshirley4695]

Then transfer the battery tray on the other side

[@jarviscrawford7194]

How long did it take for your car to get to its top speed im looking at the 41 23 it sounds good but can it reach that speed in a 132? An witch gear ratio was faster reaching its speed

[@revee1000]

I have a question. For speed runs what is the difference between running a 4400kv motor on 3s to a 3300 kv on 4s ? They have about the same rpm

[@twofortyrida]

Heat build rate from current and your specific esc ability to keep up plus gears

[@bearbeezall]

What's the equivalent in Gears sizes like 32p or Mod1 or Mod 1.5? Example: 32p 20T pinion is the same as what size in Mod1?

[@paulclancy2404]

Sorry not about the video but have a question. Capacitors are for no interuption in current is adding capacitors allowing the esc to run cooler as it dosen't have to start over every time we go off throttle back on . I had esc that would overheat but once I added a cap pack it runs alot cooler

[@RCexplained]

Take a look at this video. Hope it helps. kzbin.info/www/bejne/mH65d2OFg7uFn7s

[@nevilledonovan8705]

What’s tha shaft size on dat motor n where cn I get pinions?

[@MrGeert1972]

8mm and saga gears

[@twofortyrida]

I've done over 114mph twice with a gear change, home made spool, hoons and some freebie mods to an otherwise OEM v5 Typhon. Why all the expense on this?

[@RCexplained]

It was a subscriber build. Subscribers selected the power system.

[@letzvisit1661]

What is the v2 diff gears sizes the pinion and spur?

[@OnlyDayzfanz]

Very conservative build (very) great video n information 👏 😉

[@fabb60]

Thank you

[@1badbrutha]

How would I calculate the gearing for 132ft drag for this same motor in the limitless with xlx2

[@OldGreyBeard45]

I'd start at 44/24-25 and use some throttle speed tuning

[@DonChilon210]

Currently @45/26 still get excessive amp load off the line if a little prep is on the tires.

[@cankoral8417]

where the 64 spec comes from? is it noted at the motor specs sheet?

[@RCexplained]

Measured and converted back to total tooth count.

[@CSL33]

Voltage per cell used is ridiculously low...???

[@RCexplained]

Yes, it can get quite low under load. The newest version of the calculator estimates this value using an approximate current draw and IR of the pack.

[@nelissuh]

With that motor, the target should be at least 150MPH! Here, Raz Shiffrin hit 180 with the same motor and platform: kzbin.info/www/bejne/jHSzmKuvpa-hmdk

[@RCexplained]

The goal was a 100mph build. Subscribers selected this motor for the goal.

[@bramnelissen9106]

@@RCexplained I understand. But it is like selecting a Porsche to reach 100mph on a racetrack. Please re-adjust your goals after reaching the 100mph goal (which is not really a goal with this hardware!).

[@toysforboysrc]

I have an important question….. Why does data log tell me my 1717/1650kv is running @ 75kRPM on 6s and 89kRPM on 8s?? Am I under geared at 21T 46 stock spur diff??? 64mph 6s 75mph 8s Runtime 40+ minutes Motor temps 130’s on6s & 140 on8s

[@tjkj-om9oi]

Don't know if you have figured it out yet but you must set the castle link to 4 pole motor, its default is set for a 2 pole motor.

[@toysforboysrc]

@@tjkj-om9oi .. yea but thanks it’s the consideration that matters at this point😉 I went from that to solving the xlx2 rev-match “problem” and some ppl didn’t know that could be fixed untill they saw the video.

[@rickthompson7335]

Why waste all this time to say what you’ve calculated really doesn’t matter at the end 🤷🏼‍♂️ gear speed cost 0.99 from the App Store btw.

[@lowridr2]

Just slap something in and let’s go man doing a little too much for 100mph

[@OnlyDayzfanz]

Once you are a member 😜

[@mikewest712]

1:1 ratio and let's see what happens.

[@franklinlourens5561]

👌🏿

[@dougkreutz7701]

You need a new shirt. Yours saying 100 km/h that's only 62.5 mph buddy. He'll my 2s drag car runs that fast in 132 feet.

[@RCexplained]

This is where the shirt line starts. Which one do you have?

[@lowridr2]

No kidding lol

[@OnlyDayzfanz]

Good points but a target of 100mph with a 1721 ok bud!

[@OnlyDayzfanz]

Wtf on this video 🤣

[@rickthompson7335]

Agreed, I’m at 139 so far with my limitless running a 1717 1650kv and xlx2…I only let the whole video play so I could respond to your comment and read the other ones 😂🤣 I’ve had an arrma vendetta almost to 120 on 6s lol. 100 isn’t that impressive running the motor he’s using.

[@chrisarnold4128]

I do watch some of your videos. I’m still not sure whether you are talking a load of shit. The KV you talk about with motors is the unloaded speed. The KV is a lot slower under load.

[@RCexplained]

Hi Chris thanks for the comment. Are you saying that you missed the part in the video that shows how load is captured in the calculations? Did you run through the calculations to be able to pick it out? Are you able to quantify what you mean by "a lot"?

[@chrisarnold4128]

@@RCexplained You cannot put an exact figure on how much an individual motor will lose KV on load. There are so many variations. Mostly weight of the vehicle, grip of the tyres, energy lost from motor to wheels. You can only have a rough idea of potential speed of the vehicle. I would say if you can predict the speed of a vehicle within 5% you are doing very well.

[@1521joe]

Looking forward to the next video