What you say is theoretically correct but the point is : by how much ? The answer, based on actual data and on discussions with people having first hand experience and knowledge of the argument, is : not as much as you think. Sure, without disturbance it would be better, but even without disturbance you wouldn’t have many chances to overtake anyway.DaveKillens wrote: Take the same two cars, and plot where they accelerate coming out of a corner. The car behind, because it has less grip, cannot accelerate at the same point as the car in front, and thus enjoys less acceleration.
Furthermore the biggest problem of disturbance is at corner entry and mainly because the driver loses confidence on the front end due to the shifting of the aero balance.
I said that the problem is the time spent at top speed. IRL cars are constantly at >90% of top speed and banking allows different lines for the corner. In an oval, even if the speed difference is tiny and an overtake requires the cars to stay side by side for 4 or 5 km, they can do it. F1 cars can’t.ZE.FT. wrote: I dont think that speed or lack of speed(for the trailing vehicle) is the reason for lack of overtaking manouvers.
Straight speeds did not change a lot during the last 20 years of formula 1.
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Also permanent drafting at very high speeds with more equal matched vehicles at the IRL ovals undermines this.
To explain in an, hopefully, better way what I was trying to say, I modified a car acceleration simulation I made a couple of years ago to calculate, in very first approximation, how much space (because it’s the space the important variable in the overtake) a following car needs to close a given time gap from a leading car, with both cars, identical cars, accelerating from a given speed to the top speed. To simulate the drag reduction due to slipstream I used the data from the drag vs distance based on the Advantage CFD study published on RCE last year. Since the data are for a speed of 320 km/h I applied a conversion to the distance, multiplying the effective gap for the ratio between 320 km/h and the current car speed, hence having a “wake length” growing linearly with speed. I read once an interview with Pat Symonds and he said IIRC that the “wake length” growths more than linearly with speed hence my conversion probably makes the reduction of drag, at lower speed, more effective than a more accurate study would actually show. Furthermore there’s no loss of downforce for the following car. As you see that’s best possible situation for drafting, aero gives only advantages without disadvantages.
I used 3 different starting speeds and 4 different initial gaps and I stopped the simulation when the gap was 1 car length (4.5 m) following the logic that if you are behind more than 1 car length the driver in front will almost surely close the door. Drag was set to achieve a top speed of 307 km/h. (top speed in Malaysia)
Here the results, in the last two columns you have the maximum gap and the distance, from the start of the simulation, at which the maximum gap occurred, meaning that up to that point the car behind was losing meters due to acceleration, only after that point the gap start to decrease. Using these result you can plot qualitatively the curve gap vs space.
initial speed (km/h)/ space needed (m)/maximum gap (m)/dist for max gap (m)
Initial gap 0.1 s
90 : 235 / 5 / 115
120 : 245 / 5.5 / 108
150 : 250 / 6.2 / 100
Initial gap 0.2 s
90 : 500 / 11.8 / 180
120 : 505 / 12.5 / 160
150 : 502 / 13.1 / 150
Initial gap 0.3 s
90 : 715 / 19.2 / 220
120 : 710 / 19.9 / 200
150 : 705 / 20.5 / 185
Initial gap 0.4 s
90 : 930 / 27.5 / 265
120 : 925 / 28.5 / 250
150 : 915 / 28.6 / 240
Given the obvious limitations of this first order simulation, you can see, that with an even small gap of just 0.2 s, you need a space in the order of half a km, in the most favourable conditions, to have a physical, theoretical, possibility (assuming the driver in front doesn’t try to stop you) to overtake. Now consider how many times two F1 cars are distant just 0.2 s and how many times, in the typical layout of F1 circuits, you have more than half km of straight line between two corners.