atanatizante wrote:I dunno if it`s the best thread to talk about this matter but it`s the following reasoning right to take into account? :
2013 : with a 641kg min. allowed car, then for 10kg of fuel (not 10 litres, coz density is lower than 1) worth it on average 0,35 sec/lap
2014 : with a 691kg min. allowed car, hence a 7,8% increase, therefore for a 10kg of fuel the time loss will be on average 0,377 sec/lap
We can only make very very rough assumptions on that so far. What we do know is the simple physics. Let's assume most of the time is lost in the power-limited parts of the track (i.e. where you can confidently be full throttle). Let's make another big assumption that acceleration is constant. Then we can say for that straight:
s = a/2 * t²
=> t = sqrt (2s/a))
Since F=m*a, a 1% increase in mass results in a ~0.99% decrease (1/1.01) in acceleration resulting in a ~0.5% increase (sqrt(1.01)) in time needed to cover the same distance on the straight.
So if we're talking about 10kg of fuel, in 2014 this will be a smaller percentage of the total mass. So a smaller percentage of time will be lost on the straight. But the overall lap time will have gone up anyway so a smaller percentage may still result in a similar absolute time.
All of this is full of assumptions (no aero drag, neglecting the existence of something like a torque curve, didn't look at the time lost in corners, etc.) so it has little to do with reality. But it shows at least that you cannot follow simplistic reasoning to determine the time you lose for adding weight.
So the influence of fuel on board is also increased and we could see this year some fuel management scenarios like 90kg of fuel from start to finish and this could worth in a 50 lap race a woooping 18,85 sec. gain at the end of the race …
First of all they all end with nearly empty tanks so in lap 50 there is no more advantage. So let's make it 9.425s. Second, you will have only 90% of the energy to spend during the race which means basically you will be at 90% power (again very simply put). Taking 90kg when 100 is allowed will NEVER work.