Does rewiring a motor give the can more power

[Speed2]

I a friend who I had challenged to a race. Where I live we used to do 4s drag races with our boats. I had beaten all the fast guys in the group so I was called the 4s king.

I was bragging that no one could beat my 4s setup. I managed to get 2 persons interested in challenging me. We had some good races I had lost some of the races.

I was using a leopard 4092 2080kv, the other men used neus and lehners. I had lost some races to a neu 1527 competition wind, it had a higher kv than my leopard. I had also lost to a lehner 2260 which also had a higher kv than my leopard.

So I had accepted that the neu and lehner where superior to the leopard.

I give my friend a new challenge, I told him if he had the same hull, the same motor he could not beat me.

He bought a pursuit and a leopard 4092 2080kv. Another friend had warn me about him, like he was cheating but he he did not say exactly what he did but he was giving me hints.

On the day of the race I received the worse beaten I had ever gotten. His boat was so far ahead of mine I was trying figure out for the rest of the day and the following days how that was possible. He told me the race was over and he no longer wanted the motor, so he was selling the motor. I made him an offer a bought the motor.

After looking closely at the motor I notice the motor wires was much shorter than the regular motor and the wires was much thicker than the regular leopard. I did a kv test with a datalogging esc, the kv came out to be 2751kv.

This is where things get interesting, I did a run and datalogged the run with an xlx2 esc. When I saw the loaded rpm I was amazed at the numbers. Well I did many datalogs with like 5 different motors and what I found the leopard my friend rewired have way more power in the can than all the other motors I tested.

To give an idea of the power of the motor it have an extra 10mph in the can over the regular 4092 that I have. Example if I push the regular 4092 to it max what ever speed the regular 4092 does that rewired 4092 can give an extra 10mph or more over the regular 4092.

So what I am trying to figure out is if rewiring a motor can add extra power to the can or is the new leopards cans after 2021 is more powerful than those from 2017.

[donhuff]

If rewinding can "ADD" power, all depends on the particular motor. In the case of the little AquaCraft 3656 that I started out rewinding, yes a rewind will add power. That's because those motors had such a small amount of wire in them from the factory. I was able to double, or more, the amount of copper in them, and that did add some power. Same goes for the old Dynamite 1500. But with the better quality motors, that's not the case. Most of them are full of wire, BUT that wire is not always the best copper. As is the case with almost anything made in China, 99.9% pure might not be what I would call 99.9% pure!

While the purity of the copper will have some affect on performance, the big difference is in the coating on the wire. Most all brands of motors use a coating that makes it easy for the manufacture to solder the wire when assembling the motor. And this coating is fine for 99% of it's customers, but that other 1% of us that wants to get every last drop of power they can, like to win a drag race. We push beyond the limits of that coating, and that's in the form of heat, which is the major limiting factor in our motors. The wire that I use in my rewinding is sold by Temco and has a 200*C rating. Most of the motors are wound with wire with a 150*C rating. That extra 50 degrees allows you to push that motor just a little harder, which is where the extra power comes from. The two motors that I know of that have the good wire in them are NEUs and TPs.

Brushless motors make peak power usually right around 50% of their UNLOADED peak rpm. But we cant usually operate at that amount of load for but a few seconds, because heat build up very fast and we cant get rid of it fast enough. Typically, operating at 80% of peak unloaded rpm is a good place to prop at. This will give you good power and produce a reasonable amount of heat, that you can get rid of through the cooling jacket. With data logging, make a lap and look at the data. Adjust your prop size to get your rpm close to that 80% number, on the straights, in the turns it'll lug down to 75-70%. But then on the straights it'll unload and cool back down. Proped like this will make your motor last a long time during 6 lap races. For a drag race or SAW run, you'll probably prop with a little more load. And that's ok because it only last a few seconds, just don't do it 6 times in a row without a cool down period.

[donhuff]

So why did the guy out run you with the same motor??? RPM I would think.

I Know of no kind of racing where more rpm is not faster. I have seen this played out in every kind of racing that I have been involved with. Your buddy had about 10,000 more rpm than you did. And something that the high rpm does is it requires a smaller prop. That smaller prop has less of an affect on the handling of the hull, it doesn't "torque" the hull over on one side. That lets the hull and the driver, have a much easier time getting the hull up on plane and settled in to the speed. Being able to get up to speed quicker means everything in a drag race.

In my straight away running, Im adjusting the kv on my different class motors so that all three classes that I ran all had the unloaded rpm right around 70,000, and on the water it was 50000 to 56000. I was using a TP 4070 motor and abc 1714 prop. We tried a tp with 2080kv and an 1815 abc, because my 8s class motor was at the bottom of the pond in what's left of my 8s rigger, but it upset the hull so bad that I had to build up another motor from parts to get the kv up to 2250. The hull settled down then and we got a 95 mph pass! RPM wins races almost every time.

[Peter A]

I a friend who I had challenged to a race. Where I live we used to do 4s drag races with our boats. I had beaten all the fast guys in the group so I was called the 4s king.

I was bragging that no one could beat my 4s setup. I managed to get 2 persons interested in challenging me. We had some good races I had lost some of the races.

I was using a leopard 4092 2080kv, the other men used neus and lehners. I had lost some races to a neu 1527 competition wind, it had a higher kv than my leopard. I had also lost to a lehner 2260 which also had a higher kv than my leopard.

So I had accepted that the neu and lehner where superior to the leopard.

I give my friend a new challenge, I told him if he had the same hull, the same motor he could not beat me.

He bought a pursuit and a leopard 4092 2080kv. Another friend had warn me about him, like he was cheating but he he did not say exactly what he did but he was giving me hints.

On the day of the race I received the worse beaten I had ever gotten. His boat was so far ahead of mine I was trying figure out for the rest of the day and the following days how that was possible. He told me the race was over and he no longer wanted the motor, so he was selling the motor. I made him an offer a bought the motor.

After looking closely at the motor I notice the motor wires was much shorter than the regular motor and the wires was much thicker than the regular leopard. I did a kv test with a datalogging esc, the kv came out to be 2751kv.

This is where things get interesting, I did a run and datalogged the run with an xlx2 esc. When I saw the loaded rpm I was amazed at the numbers. Well I did many datalogs with like 5 different motors and what I found the leopard my friend rewired have way more power in the can than all the other motors I tested.

To give an idea of the power of the motor it have an extra 10mph in the can over the regular 4092 that I have. Example if I push the regular 4092 to it max what ever speed the regular 4092 does that rewired 4092 can give an extra 10mph or more over the regular 4092.

So what I am trying to figure out is if rewiring a motor can add extra power to the can or is the new leopards cans after 2021 is more powerful than those from 2017.

Obviously he cheated, with nearly 700kv more he was not using the 'same' motor. It might have been the same can, but a different wind. If he had been using the same he would have used a 2080 kv motor and it would have come down to set up, prop and driver! You got robbed dude!

[Speed2]

The motor that I discribed will turn the same size prop or an even bigger prop than the regular 4092.

In the area where I run an abc 2014 15 60 3 blade on 4s will bog the regular 2080kv 4092, kv down to 72% of the unloaded kv (1541kv).
You would expect with a higher kv of the same can you would have to prop down.
With this motor if I was to uses the same 2014 15 60 3 blade on 4s, my kv would be 72% of 2751kv, 1980kv. Once you have a strong enough battery and a capable esc the motor have the torque to hold rpm better than the regular motor.

I have tried the tp 4060 1950kv and that don't have nowhere near the power that this motor have. The same 2014 3 blade abc bogs the tp down to around 72 to 73% of the unloaded kv on 4s where I run.

[donhuff]

Have you opened up that motor to be sure it has Leopard 4092 internals? TP makes a 4070 (10mm longer than the Leo) 3D 2700kv. And I'm, pretty sure that the TP guts will slide right into a Leo case.

Is the wire dark colored or bright copper? TP uses the good wire, Leopard does not.

It's very hard to increase the torque of a motor, without some major parts modding or swapping. Narrower rotor to stator air gap, larger diameter rotor, and more wire, if it didn't have enough wire in the first place.

[Speed2]

The motor is wired 2d, the strands for the windings are of a bigger gauge than the leopard and tp motors. The can is full of copper to the point that the winding in basically touching the cap at the top of the motor and the other one to the bottom of the motor.

I have push the regular 4092 2080kv to a 295amp load. I have datalog numbers for the regular 4092 from 80 amps up to 295 amps. I does prop to get 70 to 75% of the kv loaded for the kind of running that I do. The regular 4092 2080kv that I have drops to 70% of the kv at 239amps. The regular 4092 is 2.5d. So basically at 598 ampere turns the regular 4092 2080kv, have it's kv at 1498 rpm/v. 70% of the unloaded kv according to the datalog.

The rewired 4092 is wired at 2d. I have data up to 410amps. At 410amps the kv of the rewired leopard is at 70.8%. 1948kv, this is at 820ampere turns.

Base on what I gathered from you response the winding maybe the reasons for the added torque.

Thankyou for the responses.

[donhuff]

NO , I don't think you understood me at all. rewinding does NOT add torque in a motor like the Leopards. It doesn't because those motors are pretty full of wire from the factory. A 2D WOULD have a little more wire in half of the slots because, a half turn wind leaves a little bit of empty space in half the windings to make a half turn, on a 4 pole 12 slot motor like the leopard. But that would not affect the TORQUE but a by a small amount.

And with wire touching the end bells of the motor, if it was just more wire in the 4092 stator, that would mean that the "end turns" of the wire going through the slots was bigger/longer. And any wire that is not in the slots does not do any work and adds nothing to the power of the motor. The end turns are mostly wasted copper and make useless heat.

The easier way to make the wire touch the end bells and add torque/power is to put bigger motor parts into a smaller case.

[donhuff]

How do you know that his motor is a 2 Delta???

Most all of the motors that I have torn down use 27 gage wire. I have seen a couple of Neus with larger gage, but most of them are 27 or very close to that.

Now I can say that the LEADS going into a 2D wind would be bigger around than would the leads be on a 2.5D . That's because if a slot will hold 100 strands, to be full with a 2D the leads would have 50 strands, and make two passes through the slot, to make 2 turns. Using the same gage wire, a 2.5D wind would have to have 33 strands to be able to go through that same size slot 3 times for a total of 99 strands in the slot. This is for 3 coils on one half of the stator, then for the other half of the stator, that same lead will make only 2 passes through the slots. That's where the 1/2 turn comes from. That makes a total of 2.5 turns ( that's how some say it), or 5 total turns, which is how others say it, and that's how I like to say it is total number of turns per leg.

[Speed2]

How do I know its a 2d?

He told me.

[rosi_99]

I a friend who I had challenged to a race. Where I live we used to do 4s drag races with our boats. I had beaten all the fast guys in the group so I was called the 4s king.

I was bragging that no one could beat my 4s setup. I managed to get 2 persons interested in challenging me. We had some good races I had lost some of the races. fnaf

I was using a leopard 4092 2080kv, the other men used neus and lehners. I had lost some races to a neu 1527 competition wind, it had a higher kv than my leopard. I had also lost to a lehner 2260 which also had a higher kv than my leopard.

So I had accepted that the neu and lehner where superior to the leopard.

I give my friend a new challenge, I told him if he had the same hull, the same motor he could not beat me.

He bought a pursuit and a leopard 4092 2080kv. Another friend had warn me about him, like he was cheating but he he did not say exactly what he did but he was giving me hints.

On the day of the race I received the worse beaten I had ever gotten. His boat was so far ahead of mine I was trying figure out for the rest of the day and the following days how that was possible. He told me the race was over and he no longer wanted the motor, so he was selling the motor. I made him an offer a bought the motor.

After looking closely at the motor I notice the motor wires was much shorter than the regular motor and the wires was much thicker than the regular leopard. I did a kv test with a datalogging esc, the kv came out to be 2751kv.

This is where things get interesting, I did a run and datalogged the run with an xlx2 esc. When I saw the loaded rpm I was amazed at the numbers. Well I did many datalogs with like 5 different motors and what I found the leopard my friend rewired have way more power in the can than all the other motors I tested.

To give an idea of the power of the motor it have an extra 10mph in the can over the regular 4092 that I have. Example if I push the regular 4092 to it max what ever speed the regular 4092 does that rewired 4092 can give an extra 10mph or more over the regular 4092.

So what I am trying to figure out is if rewiring a motor can add extra power to the can or is the new leopards cans after 2021 is more powerful than those from 2017.

Changes to the Leopard engine cans after 2017 are unlikely to be the main cause of the power difference.

[Speed2]

Actual changes to the leopard stator is the reason for the power difference. I bought a new leopard 4092 2080kv after starting this tread and seeing the responses. I was convinced the new Leopard can had to be more powerful.

So I datalogged the new leopard and the old leopard and if found that the new leopards separates its self from the old over 200 amps. I have data on the old can up to 290 amps and I have data up to 310 amps on the new can.

At 290 amps the new can is 12 percent more efficient than the old. Well that is the kv is 12 percent higher on the new can (2023) over the old can (2016).

[donhuff]

I have worked ? rewound a few hundred Leopards, some the X2 version but most are the older model. And holding the two stators in my hand at the same time, comparing them, I can not find any difference. There should be a difference because they mark each one with a magic marker at to which model and wind they are.

The only non obvious difference I can think there "might" be is that the X2 stator plates are made from a better grade of silicon steel, which could account for the increased price.

A 12% increase in efficiency would amount to a HUGE increase in power!