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There's no way he's getting 700+ HP from those two warp 9 motors. It says each motor is capable of outputting 34HP continuously: http://electriccarinternational

There's no way he's getting 700+ HP from those two warp 9 motors. It says each motor is capable of outputting 34HP continuously: http://electriccarinternational.com/media/img-prod/WarP_9_Sales_Sheet-1.gif http://electriccarinternational.com/media/img-prod/WarP_9_Sa...

mercuryrising 14y ago
Nope, but it will drive a car, just not as fast as I'm sure he would like. When he realizes his error, he'll be able to reason much better about electrical and mechanical engineering than many of his peers in school (if he decides to go to college) due to having actual experiences of failing in the real world (rather than just on paper). Good for him.
- SunboX 14y ago
  I also don´t see any kind of transmission. I don´t think it´s a good idea to mount the motors directly to the drive shaft. Edit: http://electriccarinternational.com/media/img-prod/WarP_9_Sales_Sheet-1.gif http://electriccarinternational.com/media/img-prod/WarP_9_Sa... mentions 5.800 RPM (min. 2.000, max. 5.800 RPM). Thats too much to drive the wheels directly. Does anyone see a gearbox in the forum?
  - mbell 14y ago
    It still has a rear differential, stock ratio is 4.10.
Zak 14y ago
That appears to be at 144 volts and 500 amps. His stated plan is to deliver 343 volts and 2000 amps. Assuming this doesn't melt the motors, he'll get more power than the datasheet claims. That said, his calculations might be a bit off. 144Vx500A = 72KW or 96.5HP. He's assuming 85% efficiency, which would give 82HP, not 34. Furthermore, if the motor were to deliver 100 ft-lbs of torque as stated at its stated maximum speed of 5800 RPM, that would be 110HP. This would obviously require more than 72KW of electrical power input. Taking the ratio between the motor's stated performance and the electrical numbers given on the datasheet, and multiplying by the electrical power he intends to supply, we get 34/96x920 = 326HP. This too seems a bit off, as 35% efficiency is quite low for an electric motor. My guess is that the motor is actually incapable of producing its full torque at higher RPM. My guess is he will actually produce something resembling the amount of power he's hoping for, but only briefly, after which they will deliver no power at all, ever.
- jrabone 14y ago
  Without the torque-speed curves for these motors, you just can't tell. The actual graphs are at http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg and http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg My guess is that the motor is actually incapable of producing its full torque at higher RPM. Correct. At 100 ft/lbs the speed drops to just over 2000 rpm. I would guess these motors have a thermal fuse wound into the stator coil (source: spent a summer in a rewinding shop), and if he tries to drive them much outside the design limits, they'll simply cut out, perhaps permanently. EDIT: the datasheet mentions a temperature snap switch, so it sounds like they have a non-permanent cut-out on thermal overload.

mercuryrising 14y ago

Nope, but it will drive a car, just not as fast as I'm sure he would like. When he realizes his error, he'll be able to reason much better about electrical and mechanical engineering than many of his peers in school (if he decides to go to college) due to having actual experiences of failing in the real world (rather than just on paper). Good for him.

SunboX 14y ago
I also don´t see any kind of transmission. I don´t think it´s a good idea to mount the motors directly to the drive shaft. Edit: http://electriccarinternational.com/media/img-prod/WarP_9_Sales_Sheet-1.gif http://electriccarinternational.com/media/img-prod/WarP_9_Sa... mentions 5.800 RPM (min. 2.000, max. 5.800 RPM). Thats too much to drive the wheels directly. Does anyone see a gearbox in the forum?
- mbell 14y ago
  It still has a rear differential, stock ratio is 4.10.

Zak 14y ago

That appears to be at 144 volts and 500 amps. His stated plan is to deliver 343 volts and 2000 amps. Assuming this doesn't melt the motors, he'll get more power than the datasheet claims. That said, his calculations might be a bit off. 144Vx500A = 72KW or 96.5HP. He's assuming 85% efficiency, which would give 82HP, not 34. Furthermore, if the motor were to deliver 100 ft-lbs of torque as stated at its stated maximum speed of 5800 RPM, that would be 110HP. This would obviously require more than 72KW of electrical power input. Taking the ratio between the motor's stated performance and the electrical numbers given on the datasheet, and multiplying by the electrical power he intends to supply, we get 34/96x920 = 326HP. This too seems a bit off, as 35% efficiency is quite low for an electric motor. My guess is that the motor is actually incapable of producing its full torque at higher RPM. My guess is he will actually produce something resembling the amount of power he's hoping for, but only briefly, after which they will deliver no power at all, ever.

jrabone 14y ago
Without the torque-speed curves for these motors, you just can't tell. The actual graphs are at http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg http://www.go-ev.com/images/003_09_01_WarP_9A_Graph.jpg and http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg http://www.go-ev.com/images/003_09_02_WarP_9_SpreadSheet.jpg My guess is that the motor is actually incapable of producing its full torque at higher RPM. Correct. At 100 ft/lbs the speed drops to just over 2000 rpm. I would guess these motors have a thermal fuse wound into the stator coil (source: spent a summer in a rewinding shop), and if he tries to drive them much outside the design limits, they'll simply cut out, perhaps permanently. EDIT: the datasheet mentions a temperature snap switch, so it sounds like they have a non-permanent cut-out on thermal overload.