3 ms·

>this can be a downside for crawling like this because it has no way to send torque from one side to the other I'm pretty sure that there'll eventually be some

>this can be a downside for crawling like this because it has no way to send torque from one side to the other I'm pretty sure that there'll eventually be some sort of LSD/locking programming for electric motors. Take the existing F-150 Tremor for example. It comes with a locking rear diff and a Torsen diff in the front axle. If you have a quad motor vehicle, someone could easily write a "locking rear diff" mode that simply has the rear motors turn at the same pace, and then have a "Torsen diff" mode for the front that will modulate the front motors just like a Torsen diff would.

SigmundA 3y ago
It's not about turning at the same pace, the side that has no traction cannot send its torque to the side that does without a mechanical connection. Each wheel is limited to the maximum torque of a single motor vs torque being sent to all wheels in a traditional single ICE engine with transfer case and lockers. You can see a quad motor Rivian performing worse than the new dual motor due this issue, the dual motor can use brake locking to send full torque from one side to the other, the quad motor cannot: https://youtu.be/I9J52zE5boc?si=Fn1KA6Mtb_FFTGDc&t=2652 https://youtu.be/I9J52zE5boc?si=Fn1KA6Mtb_FFTGDc&t=2652
- deelowe 3y ago
  You just need motors large enough to break traction. After that, it's irrelevant. Doesn't seem impossible to me.
  - SigmundA 3y ago
    Yeah just need larger motors that can put out more torque which adds more cost and weight. Or you can have a way to connect each side with a locker or a single larger motor with brake locker control like dual motor vs quad motor Rivian's. Again the quad motor Rivian can be stalled on rock crawling due to lack of torque when multiple wheels lose traction. Electric motors have a lot of torque but EV drive trains are usually single speed so it must not have too much gear reduction for highway speed. A modern ICE offroad vehicle has a multispeed transmission with torque converter that greatly amplifies stall torque along with a transfer case that has a low range that multiplies even further. I would imagine when jeep does an electric production Wrangler it will probably have dual motors with lockers and may even have a 2 speed transmission for low range. Maybe they will even do like their Magento prototype and run a single large electric motor through a traditional transfer case and driveline.

SigmundA 3y ago

It's not about turning at the same pace, the side that has no traction cannot send its torque to the side that does without a mechanical connection. Each wheel is limited to the maximum torque of a single motor vs torque being sent to all wheels in a traditional single ICE engine with transfer case and lockers. You can see a quad motor Rivian performing worse than the new dual motor due this issue, the dual motor can use brake locking to send full torque from one side to the other, the quad motor cannot: https://youtu.be/I9J52zE5boc?si=Fn1KA6Mtb_FFTGDc&t=2652 https://youtu.be/I9J52zE5boc?si=Fn1KA6Mtb_FFTGDc&t=2652

deelowe 3y ago
You just need motors large enough to break traction. After that, it's irrelevant. Doesn't seem impossible to me.
- SigmundA 3y ago
  Yeah just need larger motors that can put out more torque which adds more cost and weight. Or you can have a way to connect each side with a locker or a single larger motor with brake locker control like dual motor vs quad motor Rivian's. Again the quad motor Rivian can be stalled on rock crawling due to lack of torque when multiple wheels lose traction. Electric motors have a lot of torque but EV drive trains are usually single speed so it must not have too much gear reduction for highway speed. A modern ICE offroad vehicle has a multispeed transmission with torque converter that greatly amplifies stall torque along with a transfer case that has a low range that multiplies even further. I would imagine when jeep does an electric production Wrangler it will probably have dual motors with lockers and may even have a 2 speed transmission for low range. Maybe they will even do like their Magento prototype and run a single large electric motor through a traditional transfer case and driveline.