Thanks a lot for those numbers.
So you are saying that the e-tron quattro system can be used to improve traction as it can be activated in high speed corners (above 120 km/h)?
I have a followup question. How long (minimum, average, maximum) do these braking moments take? According to the rules the braking must last more than 1 second.
Quote:
- The amount of energy used between 2 braking must not exceed 0.5 MJ.
- Braking is a deceleration of the car greater than 2g.
- Braking lasting under 1 second will not be taken into account.
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With 150 kW generators and a round-trip efficiency of 70%, the braking must last almost 5 seconds in order to recover enough energy to release 500 kJ after the corner.
With this limitation it seems desirable to make the capacity of the energy storage medium (battery, capacitors, flywheel, etc.) bigger than 500 kJ. In this case, more energy can be stored than necessary, if the braking takes longer than 5 seconds. This reserve energy can later be released after a braking zone that is shorter than 5 seconds.
If Toyota can apply 1 MJ between braking zones, they need a bigger generator because they have to recover more than 10 MJ per lap with only 34 seconds of braking. The generator has to be 300 kW! Unless of course they count less than 10 KERS activations. In general, it will be though to harvest/release this 1 MJ on a track like Le Mans with limited braking.