The Drayson electric racer, and big eletric car torque con

[Wafer_Thin_Ham]

https://www.youtube.com/watch?v=q_cRqcbXAs4

This is Lord Drayson's new electric race car. Only they took out at the V10 Judd and replaced it with electric batteries and motors.

They claim it has 2000ft lb of torque.

Don't get me wrong it's a fantastic bit of kit, as I'm sure you'll appreciate if you watch the video. The one thing I have an issue with, which is the same across all electric cars, is the torque figure.

We (and the general populace) all sit here think holy crap, 2,000ft lb is an obscene amount of torque. How does it not shred it's tyres? When we all have EVs they'll need to replace the tarmac at tarmac lights weekly due to it being all rumpled up.

The confusion is that they measure the torque of an internal combustion engine before the gearbox. They measure the torque of an electric vehicle at the wheels. The electric motor usually has an internal gear before it reaches the wheels, yet they still measure the output at the wheels, rather than at the motor prior to the gear.

As an example an R8 V10 when measured the same way produces 4,810ft lb of torque.

Electric motors do let yuo access peak torque immediately and maintain it for longer, but they're not as torquey as the numbers suggest.
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[D O G]

[Wafer_Thin_Ham]

[G]

[lihp]

You need all the figures for it to be meaningful.

Torque to know what work can be done, and power to know at what rate/speed the work can be done.

Low power high torque, may be able to do a shed load of pulling (like a tractor) but it may take it an age to do it.

Additionally, not all electric motors are the same so it's difficult to say how it has been measured without access to the procedures and motor spec.

For example, one of the motors we run at work has no gearing, as it mates up to a gear box.

In fact, every motor I have come across has been rated without the gearbox involved.
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covent.gardens: lihp is my most favourite member ever

[Aff]

[Wafer_Thin_Ham]

[Nick 50]

Great video and great to see someone who obviously has a great care for what he is doing.

I'm currently doing a project at Uni which isn't too dissimilar, though with a significant smaller budget and spec.

But seen the vid going round the car:

Wishbones: They look very similar to my design at present.
Calipers, they are AP Racing... so are mine.
YASA Motor... so are our ours.

It's like a very fancy (plus much better) formula student car.
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