# Kostov motor size



## TTmartin (Feb 7, 2012)

Looking for advice,
Tried ordering Kostov 144v 10" motor for my conversion but they are out of stock for at least 2 months
I have been offered a Kostov 192v 11" from stock, my limit on voltage is 144v due to space within car. How would this motor perform at this voltage compared to the Kostov 144v 10". Hopefully will be using soliton J or maybe soliton 1.


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## major (Apr 4, 2008)

TTmartin said:


> Looking for advice,
> Tried ordering Kostov 144v 10" motor for my conversion but they are out of stock for at least 2 months
> I have been offered a Kostov 192v 11" from stock, my limit on voltage is 144v due to space within car. How would this motor perform at this voltage compared to the Kostov 144v 10". Hopefully will be using soliton J or maybe soliton 1.


Hi TT,

This should be an easy answer. Post up the performance curve for each. I'll help you with the analysis. Or maybe *Plamenator* could chime in 

major


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## TTmartin (Feb 7, 2012)

major said:


> Hi TT,
> 
> This should be an easy answer. Post up the performance curve for each. I'll help you with the analysis. Or maybe *Plamenator* could chime in
> 
> major


http://kostovmotors.com 
its all here but its all abit to techi for me, help


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## major (Apr 4, 2008)

TTmartin said:


> http://kostovmotors.com
> its all here but its all abit to techi for me, help


That link bombed.


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## palmer_md (Jul 22, 2011)

144 10" = http://kostov-motors.com/files/productattachments/b4a281decf350a7f7f2b98a21ad85754_S144F06.pdf

192 11" = http://kostov-motors.com/files/productattachments/e2dd0a6a56533b75d3fb6ce7a96d2dee_perf11-192V.pdf


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## somanywelps (Jan 25, 2012)

TTmartin said:


> Looking for advice,
> Tried ordering Kostov 144v 10" motor for my conversion but they are out of stock for at least 2 months
> I have been offered a Kostov 192v 11" from stock, my limit on voltage is 144v due to space within car. How would this motor perform at this voltage compared to the Kostov 144v 10". Hopefully will be using soliton J or maybe soliton 1.


Use smaller Ah batteries for higher voltage?


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## major (Apr 4, 2008)

palmer_md said:


> 144 10" = http://kostov-motors.com/files/productattachments/b4a281decf350a7f7f2b98a21ad85754_S144F06.pdf
> 
> 192 11" = http://kostov-motors.com/files/productattachments/e2dd0a6a56533b75d3fb6ce7a96d2dee_perf11-192V.pdf


Thanks palm.

O.K. TT,

I like the 11 inch, call it the K11. They sell it as a 192 Volt motor but it will run just fine at lower voltage. In fact, that is what happens most of the time in the EV via the controller reducing the voltage from the battery to the motor.

I am not sure why you selected the K10 for your EV. It also looks like a fine motor from the performance graph. You say you're not too techi about this so I'll try to keep it simple.

The K11 is going to be somewhat larger so here's hoping it will fit your application physically. Both the K10 and K11 are rated for one hour at about 250 Amps. The K10 at 250A and 144V is 36kW (input power). The K11 at 250A and 192V is 48kW. But the K11 at 144V and 250A is 36kW, same as the K10. Since the two motors are equally efficient, both are rated at the same output power.

Motor output power is the product of torque and angular velocity (sometimes called RPM). So you can get the same power with different ratios of torque and speed. And that is the case with these two motors. The K11 will produce more torque and less speed for a certain power than will the K10.

As an example, at 250A and 144V, K10 produces 49Nm at 5700RPM and K11 produces 70Nm at 4000RPM. Same power. So all you have to do is select the proper gear ratio to use.

Another thing to consider is the maximum torque from the motor. This will depend on your controller current limit. If you use a 500A limit, the K10 will produce 122Nm and the K11 will produce 180Nm.

If you can afford the size, mass and cost, the K11 looks better to me 

major


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## TTmartin (Feb 7, 2012)

major said:


> Thanks palm.
> 
> O.K. TT,
> 
> ...


Hi Major,

Thank you for explanation, it's only been about 3 months since discovering the DIY EV world, so it's early days knowledge wise for me. This site and it's members are proving really helpful.
The k10 is a very tight fit diameter wise, due to drive shaft cv joints restrictions, a warp 9 is tight length wise so k11 will be tight both ways but ok I like a challenge.
As regards controllers I had thought the soliton junior would be about right for normal driving, but have been advised it is a little under powered for a k10 or more so for a k11. All I require is around town driving and ability to climb some hills, (the UK is not flat) I'm not looking for sports car performance? Is a soliton 1, 1000 amps a bit over the top


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## major (Apr 4, 2008)

TTmartin said:


> ......As regards controllers I had thought the soliton junior would be about right for normal driving, but have been advised it is a little under powered for a k10 or more so for a k11. All I require is around town driving and ability to climb some hills, (the UK is not flat) I'm not looking for sports car performance? Is a soliton 1, 1000 amps a bit over the top


Hi TT,

Both are rated above the motor rated current, so either will work well. The advantage of the Sol1 higher current (1000A vs 500A) is greater motor torque. More motor current; more motor torque. Of course you have gears in between the motor and the car's wheels. So a transmission can shift and multiply torque for the times you need greater wheel torque which would be for acceleration and hill climbing. Also the transmission can be used to run the motor at higher RPM at low vehicle speed for cooling purpose. Although non-hill climbing low speed is usually low power and may not need much cooling.

So in short, you'd be best to go with the big guy for direct drive and use a shifting transmission with the Jr. But nothing wrong with Sol1 and the tranny.

Cheers,

major


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## ElectriCar (Jun 15, 2008)

OP what did you settle on? I know this is an old post but I installed a K11 on my truck with a 50 cell 160 or so volt pack. Wired in series like the ADC9 I had and it works but I have a hard time keeping it cool, even with a 150cfm blower.

Some one mentioned trying the parallel field so I did. Much more manageable now but still doesn't have the torque I expected.

Now Plamenator says my pack V is too low and the K11 is a current hog at that voltage. So now I have to consider adding 10 or so batteries. That's a big deal so waiting now to see if my charger can go that high. Then it's add a smaller battery box or sell my pack and fit smaller ah cells in the existing box. It's cooled, heated and insulated so... not really excited about this. May just sell it and find another vehicle and start over. An S10 is a bit cramped for a 6' tall occupant!


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