Dropping the 1650kv

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Crafty sneak peek!

1000033734.webp
 
Ok, so the Asuga on 130mm tyres:

6S - 1680 KV - 16/52 = 38.00mm/rev rollout.

84.27 kph - 52.36 mph

6S - 1680 KV - 16/46 = 42.95mm/rev rollout

95.25 kph - 59.18 mph

So, for comparison to Nelson's app:

6S - 1680 KV - 18/52 = 42.75mm/rev rollout

94.80 kph - 58.91 mph

6S - 1680 KV - 18/46 = 48.32mm/rev

107.15 kph - 66.58 mph

The above calculations do account for some voltage sag, but do not account for mechanical losses. 👍
 
Atomic Skull said:
I use this:

https://www.rctalk.com/rc-tools/rc-car-speed-calculator/


SMC packs consistently place near the top of the RCG lipo test list, ironically the more expensive packs typically place lower. Everyone should watch this video before spending money on lipos:

Click to expand...
Just had a go on the RC Talk speed calculator - it's definitely not right. Something on that calculator causes the above numbers for the Asuga (18/46, 1680kv, 6S) to come out at 96mph on 130mm wheels. 🤣

Never going to happen. 🤣
 
Horatio said:
Just had a go on the RC Talk speed calculator - it's definitely not right. Something on that calculator causes the above numbers for the Asuga (18/46, 1680kv, 6S) to come out at 96mph on 130mm wheels. 🤣

Never going to happen. 🤣
Click to expand...
For me it said 74mph with 18T/46T and 25.2V (fully charged 6S)
 
madasuga25 said:
Nice, I still don't quite understand how gear ratios work but it must be insane with a 46 spur and large pinion
Click to expand...
You probably understand exactly how Ratios work but don't believe how simple it actually is.

How many times does 10 go into 50?

5

In gearing terms, that's a ratio of 10 tooth pinion turning 50 tooth spur.

5:1 ratio

On our rigs, these reductions take place between pinion and spur and input and crown.

So we need to take into account both reductions. Our Corally rigs have 13/43, so:

3.3:1

So basically to work out the overall ratio, we multiply the pinion/spur ratio with the input/crown ratio to get the overall ratio.

To work out speed, we need to know tyre diameter.

Once we have overall ratio, diameter, we can calculate how many mm the car rolls for one revolution of the motor - mm/rev.

Once we have mm/rev, we can calculate how many revs can our motors spin on the battery we run.

Nominal voltage of 6S pack 22.4 v (6 x 3.7v).

22.4v x 1680kv = 37632rpm

So with a value of 37632 revolutions in a minute, we can work out the distance travelled in 1 hour using mm/rev to give us a speed in km/hour it's pure arithmetic at this point. A x B x C x 60 / 1000000

Converting km/hour into miles/hour is simply a matter of dividing kph / 1.609344

🤓
 
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Atomic Skull said:
For me it said 74mph with 18T/46T and 25.2V (fully charged 6S)
Click to expand...
Tried RC talk again:

18/46

130mm Wheels

6S - 22V (taking the sag into account)

1680kv motor

1000033735.webp


Vs

1000033738.webp


They're actually pretty similar.

I have no idea why it came out at 96mph the first time I used it. 🤣

1000033736.webp
 
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Horatio said:
Ok, so the Asuga on 130mm tyres:

6S - 1680 KV - 16/52 = 38.00mm/rev rollout.

84.27 kph - 52.36 mph

6S - 1680 KV - 16/46 = 42.95mm/rev rollout

95.25 kph - 59.18 mph

So, for comparison to Nelson's app:

6S - 1680 KV - 18/52 = 42.75mm/rev rollout

94.80 kph - 58.91 mph

6S - 1680 KV - 18/46 = 48.32mm/rev

107.15 kph - 66.58 mph

The above calculations do account for some voltage sag, but do not account for mechanical losses. 👍
Click to expand...
Nice, thanks. 85km will have to do, it's definitely not slow that's for sure
 
Horatio said:
You probably understand exactly how Ratios work but don't believe how simple it actually is.

How many times does 10 go into 50?

5

In gearing terms, that's a ratio of 10 tooth pinion turning 50 tooth spur.

5:1 ratio

On our rigs, these reductions take place between pinion and spur and input and crown.

So we need to take into account both reductions. Our Corally rigs have 13/43, so:

3.3:1

So basically to work out the overall ratio, we multiply the pinion/spur ratio with the input/crown ratio to get the overall ratio.

To work out speed, we need to know tyre diameter.

Once we have overall ratio, diameter, we can calculate how many mm the car rolls for one revolution of the motor - mm/rev.

Once we have mm/rev, we can calculate how many revs can out motors spin on the battery we run.

Nominal voltage of 6S pack 22.4 v (6 x 3.7v).

22.4v x 1680kv = 37632rpm

So with a value of 37632 revolutions in a minute, we can work out the distance travelled in 1 hour using mm/rev to give us a speed in km/hour it's pure arithmetic at this point. A x B x C x 60 / 1000000

Converting km/hour into miles/hour is simply a matter of dividing kph / 1.609344

🤓
Click to expand...
I'm sort of understanding it now, it's taken me ages to understand diff weights and rc geometry but I'm getting there
 
madasuga25 said:
Nice, thanks. 85km will have to do, it's definitely not slow that's for sure
Click to expand...
No, it really isn't!

These speeds are literally insane for off road rigs, but it's hugely addictive.

Once you've got accustomed to 16/52 gearing and 84 kph (52 mph), why not try 17/46 gearing, which should get you to 60 mph in the least amount of time?

1000033743.webp


It's fun - and testing acceleration is actually far challenging than just gearing for highest speeds.

Angrysection8 is the chap to beat for insane 0-60mph times.

My T2E is routinely doing 0-60mph in 3.58 seconds using 6S and the Castle 1515. Doesn't even get warm! 😅

Typically my Kronos XTR can do it around 3.68 seconds on the Kuron 845 on 13/52 gearing on 6S, but that's using insanely heavy JetKos.

I'm going to try again with the Kuron 845 and Louise tyres on 13/46. 🤞
 
Horatio said:
No, it really isn't!

These speeds are literally insane for off road rigs, but it's hugely addictive.

Once you've got accustomed to 16/52 gearing and 84 kph (52 mph), why not try 17/46 gearing, which should get you to 60 mph in the least amount of time?

View attachment 9269

It's fun - and testing acceleration is actually far challenging than just gearing for highest speeds.

Angrysection8 is the chap to beat for insane 0-60mph times.

My T2E is routinely doing 0-60mph in 3.58 seconds using 6S and the Castle 1515. Doesn't even get warm! 😅

Typically my Kronos XTR can do it around 3.68 seconds on the Kuron 845 on 13/52 gearing on 6S, but that's using insanely heavy JetKos.

I'm going to try again with the Kuron 845 and Louise tyres on 13/46. 🤞
Click to expand...
Does the 46/17 require the adu centre and engine mount
 
madasuga25 said:
Does the 46/17 require the adu centre and engine mount
Click to expand...
No, I wouldn't have thought so. 46 spur is slightly smaller and 17 pinion is slightly bigger, so motor will be in roughly the same relative position. Should be within the limits of the Asuga's existing motor mount.
 
On the Kronos, 18/52 was about as high as I could go before being at the limits of the slidey motor mount.

After very careful dremmeling, I could do 19/52.

Getting the 46 tooth Spur opened up higher gearing options without reaching the limits.

However, the smaller pinions has the motor very close to the centre driveline, meaning you have to be careful with any heatsinks or fans that they don't foul the diff outputs. 👍
 
Horatio said:
On the Kronos, 18/52 was about as high as I could go before being at the limits of the slidey motor mount.

After very careful dremmeling, I could do 19/52.

Getting the 46 tooth Spur opened up higher gearing options without reaching the limits.

However, the smaller pinions has the motor very close to the centre driveline, meaning you have to be careful with any heatsinks or fans that they don't foul the diff outputs. 👍
Click to expand...
Sounds good, lots to work on. It's definitely a long-term project, the asuga is such a blast, every time I take it out I have so much fun
 
Asuga with 1650 & 52t

IMG_8279.webp

Can’t recall exactly but think with 1650 & 52t spur biggest pinion you can fit is 18t or 19t which is why some opt for the adu mount as it can go to 20+
 
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Nelson.81 said:
No don’t require adu mount to fit 46t spur. Think some need to check they’re calculations it’s a 1650kv motor not 1680kv & 6s =22.2v 😅
Click to expand...
🤣 Done!

130mm wheel diameter

1650kv 6S 16/52 55.63 mph
1650kv 6S 17/46 61.77 mph

This calculation takes into account sag but doesn't consider mechanical losses.
 
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