tok-tokkie wrote:xpensive wrote:While knowingly running the risk of repeating myself into absurdity, it's something like that you need to make KERS viable.
A 700 kg car reducing its speed from 250 to 100 km/h, five times over one lap, is still only 7000 kJ of kinetic energy.
At the same time, an F1 car spends more than 500 kJ of wheel-energy per second when at full power.
One liter of gasoline holds 34 000 kJ and the car spends some 3.5 to 4 liters per lap.
In a way Mario Theissen was right on KERS, but you need to let the dogs out of their boxes.
Using those figures I get this:
KERS can get 7 000 kJ per lap
1 litre = 34 000 kJ
3,6 litre per lap
Engine efficiency 33%?
So the 7 000 kJ from KERS would replace 21 000 kJ from the fuel
So it will save 21/34 litres per lap = 0.61747
The race is 60 laps
So it will save 60 X 0.61747 litres = 37.06
Density of fuel about 0,737 kg per litre
So the weight saved is 37 x 0.737 = 27.269 kg
So a KERS car (without restricted use) would start off 27 kg lighter next year when there is to be no refueling. That would be a great advantage.
xpensive wrote:Those engines were initially designed for 20k+, why I imagine they could do it again, for six seconds a lap.
If you would care to study some of the calculations made above on this thread, we could perhaps discuss your last question.
I have previously seen your anti-KERS mathematics xpensive and I have previously countered you saying that the idea is to get more energy using less fuel, anyone can dump more fuel into the engine, that is not a technical accomplishment. We have all agreed that unrestricted KERS is how they should have gone in the first place, and if that were the case I think everyone would have gone for flywheel based systems. But given the restrictions McLaren has proved that the battery was the best solution. albeit at 100K a pop, but they will make it back when they start putting it in their road cars, and it is reportedly going in the Mclaren road car as well.(not the same one, but a road going variant)
And also it would all compound itself, carrying less fuel onboard allows you to use less fuel again, so would the smaller brakes needed if all wheel KERS where allowed.
The 27kg calculated above would probly be closer to 30 kg since it does not take into account not carrying the initial 27 kg's... it is compounded... plus tire wear would improve since you have to accelerate, corner and brake with less weight.
