The wider tyres and higher downforce will not increase the peak torque. There is already more than enough grip at the start of a high speed stop to saturate the 120kw KERS. where it will come in to play is that the full torque will be available down to lower speeds, so increasing the length of time the full 120kw can be recovered, and more recovery at lower power points as well.godlameroso wrote:KERS recovery is from how much energy you can absorb by the rear axle. The tires in the back are going to be significantly wider, hence more KERS torque can be used to slow the rear wheels. More energy = more recovery, the thing that will be a challenge is designing batteries that can charge that faster than the ones they have now.
Some numbers to support that.
120 kW at 100m/s is 1200N Tractive effort. 3G on 760 kg needs 22,400N. I'm assuming a 4G peak deceleration with 1G coming from drag. So the KERS can only provide 5% of the Tractive effort.
At the other end with 400kg on the rear axle ( no aero) and an effective mu of 2.0 that's 8000 N of Tractive effort which would mean 120kw recovery at 15m/s (54kph) . That's a number that surprises me and I suspect that the gearing at low speeds will make a big difference reducing the torque, hence TE, and probably make that lower speed quite a bit higher. With 2016 tyre width 25% less that raises the equivalent low speed to 18.75m/s. (67 kph).
I'm pretty shaky on the MGU-K power/torque characteristics or what effect the 200Nm limit and gear ratios will have but I think the gist of my argument is still OK.