I don't think that's how it works. The driver is setting three different aspects of the car, which come into play at different stages of a corner. He sets all three of them well before a corner, and then focuses on braking, shifting, steering and throttling. Most onboard footage I watched seems to confirm this.
Indeed that's the case. But then you may ask why don't he set it up once for the track and be with it? The track would have to be wildly disparate to need a periodic change at certain points in a lap. Such tweaks are mostly to cope more efficiently with varying situations: for example you don't take the same line when you're basically alone or when you want to overtake, which you precisely do at corner entrance or exit - since such cars are not wildly different in power from one another - and that's something the driver plans in advance of actually doing it.
Monaco, compare the Grand Hotel hairpin with the tunnel; very different performance characteristics and diff requirements, I'd suspect.
Silverstone, look at the Becketts complex and compare it to Luffield.
Spa Francorchamps, compare the requirements of Eau Rouge with La Source.
That's just three straight off the top of my head. Circuits are pretty varied; I don't know for sure that they are doing that with diff settings as they lap but anecdotally they alter brake bias pretty regularly so it wouldn't surprise me particularly.
Which is precisely what I meant by 'disparate' :) There can be long-winded corners, and then a tight chicane in another area. A different diff setting would allow to maximize stability vs agility by balancing (forward+braking) power on left/right wheels.
> Indeed that's the case. But then you may ask why don't he set it up once for the track and be with it?
A race track is a living thing - the profile of it changes with each lap, with each race and over the course of a race weekend. There is a lot less grip at the beginning of a race weekend, a lot more later on.
The slightest changes in temperature, atmospheric pressure, etc. have a very large bearing on car performance and how the car has to be setup and adjusted for each corner.
> "There is a lot less grip at the beginning of a race weekend"
It can also be the opposite during a race, as tyre residue accumulates on the track, lessening grip in the most critical areas, often requiring drivers to change their line.
(To be clear, my question was a rhetorical one. I began to write a paragraph about that, and then another one... and then work brought me back from procrastination, so I deleted the incomplete stuff)
marbles (pieces of tyre) do not build up on the racing line. they build up off the racing line and thus are not a factor in "most critical areas". they are a factor if the driver has to go off the racing line. to defend, pass or avoid.
Remember that they're fighting for hundreds, sometimes thousands of a second, in laps that usually take 90-100 seconds. Anything that can be done to improve things ever slightly, even if it means having to do extra work for some of the corners, is worth it.
During the race, when they have the video from above the cockpit you can clearly see the drivers changing configuration all the time during the race.
