How much is a team's setup influenced by other cars?

[Moose]

and I specified that A was the optimum setup for that circuit.

So?

It is entirely possible that the car that was slower in qualifying (whether set up with either setup A or B), could be faster in the race (with either setup A or B). However, with the optimum setup (A), it would not have enough straight line speed to pass the other car. Thus, option B is the better choice of setup, despite not being the optimum for that car. Because with that setup, they will be able to pass, while with the optimum, they will not.

[Greg Locock]

I give up

[emaren]

One thing that is missing is the definition of 'optimum setup'.

The optimum setup for qualifying will take account of fuel load, tyre choice, Saturday conditions and will be pretty specialist.

The optimum race setup will be different. It will be a compromise that will work across two compounds of tyre and an ever decreasing fuel load too. Then add to that grid position and DRS zones and pit windows and driver preference. I am pretty sure looking at what others have done is a consideration too, but probably less so that the base-line race-day setup, car design philosophy (low drag etc) and driver preference.

[-Felix-]

I find this discussion nonsense because all depends on factors that can not be simplified and just ruled out and the fact that there is no "optimum setup"

[Moose]

I find this discussion nonsense because all depends on factors that can not be simplified and just ruled out and the fact that there is no "optimum setup"

Of course there's an optimum setup. There is always some setup which causes the car to complete the race in the fastest possible time. Whether the team find it or not is another matter.

[-Felix-]

You didn't get my point.

[Moose]

You didn't get my point.

Your point was that there is no optimal setup, which is untrue. An optimal setup is easily defined - it is the one that gets you from the start of the race to the end of the race in the fastest possible time.

[-Felix-]

I see what you mean. For me, an optimal setup doesn't exist because it is not possible to achieve. Simply because you can not see into future. You always have to work with best guess in some area, which means you can only come as close as possible to it. No race engineer ever has found this mathematical optimum and it will never happen. So in my view, it is impossible to have the optimal setup, you can only come close to it. But since there may be more than 1 setup that comes as close to this optimum, there is not "the one". See my point?

[Moose]

I see what you mean. For me, an optimal setup doesn't exist because it is not possible to achieve.

Of course it's possible to achieve. It's rare to achieve it, and extremely hard to recognize when you have achieved it, but it's possible.

The fact that it's hard to recognize when you've achieved it, doesn't mean we can't have a reasoned argument about whether you might deviate from it deliberately.

Furthermore, what engineers can (and do) regularly find, is a setup that is a reasonable approximation of the optimum setup. And as we're discussing, they may well then deviate from that near-optimum, because of other team's decisions.

[-Felix-]

How are you going to achieve that? How do you know before the race at which time which air/asphalt temperature, humidity, denity, maybe even rain occur?

When we are talking about your definition of the optimum setup, which will be cover the race distance in the fastest time possible, then you have to know all setup influences over the time of the race. Assuming our Car has the optimum setup for a track temperature of 40°C. After 70% of the race clouds come and track temperature is 38°C for the rest of the race. On 38°C track, the car is 0.00000001 s slower per lap than on 40°C track. So the optimum setup would have been a mixed setup of 70% 40°C track temperature optimum and 30% 38°C track temperature optimum, because the fastest optimum overall time is the sum of both part times. Since you can not determine in advance when the change of circumstances will occur, you can not mix your setup between the two optimum in the optimum ratio before the race.

Of course I am aware of this pure theoretical and mathematical and completely impractical approach, but it makes my point more clear. An optimum setup can only be achieved for a known set of circumstances. A set of circumstances can only be known for a limited amount of time, which, for example in the case of wind speed and direction, lasts very very much shorter than the amount of a race.

[Miguel]

I see what you mean. For me, an optimal setup doesn't exist because it is not possible to achieve. Simply because you can not see into future. You always have to work with best guess in some area, which means you can only come as close as possible to it. No race engineer ever has found this mathematical optimum and it will never happen. So in my view, it is impossible to have the optimal setup, you can only come close to it. But since there may be more than 1 setup that comes as close to this optimum, there is not "the one". See my point?

I'd downvote this as factually incorrect, several times, but alas, the system doesn't allow me to.

First of all, you're moving the goalposts: you've gone from "the optimal setup doesn't exist" to "it's not possible to achieve". Next time you can argue that since you cannot represent most floats exactly in computers, this hurts car setup. Using your reasoning, you could also argue that limits don't exist. Or that the hare never catches the tortoise.

Second, perfect_laptime(setup) is a multidimensional function that is reasonably continuous (discontinuities being caused undrivable setups). The region of interest is closed and bound (either by regulations or by spring characteritics). Our function is lower-bound by c/l (c is speed of light in vacuum, l is the chord of the track). If you want, we can raise this lower limit to v_term/l, with v_term being, say, the 400-something kph achieved by Honda in Utah. Whatever. As a consequence, a global laptime minimum (optimal setup) exists. Bolzanno's theorem generalised to N dimensions.

And third: you don't need a setup precission to the nanoscale anyway. It is enough to be within 1 ms of the optimal laptime, given the current regulations.

Back to the original question, I don't think it's likely anybody runs the absolute ideal setup, even if they knew it. If you define your opimum around best qualy time, then you have to compromise for two tire compounds plus fuel plus drivability in a 2h race. Since points are awarded on sunday, you may well want to define your optimum from the shortest race time. From a strategic point of view, you'd take the optimum race setup if you could qualify on pole with that. Else, you start gambling with how many positions you think you can win/lose, and whether track position is important (say Spa) or fundamental (Monaco).

[Belatti]

This year I had to setup a 140HP sport prototype car for this track:
https://www.google.com/maps/d/viewer?mi ... UTF8&msa=0

The large layout (without the chicane) has a 1000m straight and turn N1 is taken flat, so full throttle for almost 50% of the lap. After a coupe of days of testing we had 3 aero balanced setups: high, med and low Downforce. Surprisingly they give almost the same laptime: 1m28s. The difference between high and low DF was an amazing 15kph in the long straight (from 225 to 210kph) and steady lateral G went from 1.7 to 2 in the different setups.

The strategy then was: full DF to qualyfy trying to slipstream and record a "magic lap" and then low DF in the race because in the inside sectors its difficult to pass and with 225kph at the final straight its difficult for the rivals to pass.

Till then, all was theory...

After 3 races there, practice showed me that:
1) Full DF setup puts in risk tyres (temp related issue) and following another car makes you loose the DF advantage while it gets difficult to overtake.
2) Low DF setup was bad after the tyre has 10 laps when sliding is a bit more difficult to prevent. Its easier for the driver to make erros.
3) Medium DF was a good compromise both for racing and qualy, as any change in track position or condition you are not that far away of the window.

[-Felix-]

From a pure theoretical point of view (and in my view this approach is correct because the "optimum setup" is pure theoretical), there is nothing incorrect in what I have said. Of course you don't have to go to nanoscale in racing, but if you guys define the optimum setup as the fastest way around, mathematically speaking a local minimum of the function of a finite number of variables, then even the setup which comes as close as 1 nanosecond to this minimum is NOT optimum. This has nothing to do with my own practical approach to setup's whatsoever, it is you who started with the statement that an optimum setup exists and it is possible to achieve. And when you start with this theoretical statement then you have to deal with it when someone goes the full length on it. I'm fine if you don't want to accept this and I think there isn't much more I can/want to add.

[Miguel]

From a pure theoretical point of view (and in my view this approach is correct because the "optimum setup" is pure theoretical), there is nothing incorrect in what I have said.

The only thing worse than mathematically wrong is contradicting thermodynamics.

Of course you don't have to go to nanoscale in racing, but if you guys define the optimum setup as the fastest way around, mathematically speaking a local minimum of the function of a finite number of variables, then even the setup which comes as close as 1 nanosecond to this minimum is NOT optimum. This has nothing to do with my own practical approach to setup's whatsoever, it is you who started with the statement that an optimum setup exists and it is possible to achieve. And when you start with this theoretical statement then you have to deal with it when someone goes the full length on it. I'm fine if you don't want to accept this and I think there isn't much more I can/want to add.

It's you digging a hole, and have now changed the rules from classical mechanics to quantum mechanics. I can play this game. Let's start with a simple question: how do you define laptime?

[Moose]

How about, instead of playing a game, and discussing minutia of physics, and semantics of the argument, we discuss ways in which teams might adapt their setup to combat the setup of other cars