The fastest F1 car of all time?

[strad]

I have said for ages that the fuel is not the same and you just proved it.

[ChrisDanger]

Is there good evidence that this top speed was definitely achieved during that qualifying lap, and not another lap in qualifying or perhaps even FP3?

[ChrisDanger]

Teams i guess measure actual wheel speed whereas FIA i think goes purely on GPS data.

They probably have a few ways of measuring speed. I've wondered if it was maybe the airspeed from the pitot tube on the nose.

[Juzh]

What about the pit stop then, which also goes for Ferrari who has claimed a faster pit stop time then what the official recording said.
Williams official time says 1,92s while in car data says 1,89s.

As I've said. This could be the case, but then all speed traps are void.

They´re void in this particular subject as they are measuring speed trap figures not total speed figures.

Sure you can look at the speed trap and say something may be funky but you can´t use speed traps as the ultimate argument for why 378km/h is false since it´s just a speed trap, not maximum speed on straight.

One more thing to consider (which may lie near your idea of speed trap figures being void) is that FIA´s system simply is less accurate or reliable then the teams measuring system. It may get it right sometimes, but other times wrong.

Teams i guess measure actual wheel speed whereas FIA i think goes purely on GPS data.

Years and years have gone by without anyone questioning the fia timing and messuring systems, and now all of a sudden everyone thinks it's false.
Despite all this:
by the fia's telemetry he was doing 370 max. Now obviously that's less than montoya's 372 at the speed trap in monza. Should montoya also have lets say an extra 12 kmh added to him? Either way, this supposed "record" isn't a record at all.

[Juzh]

Is there good evidence that this top speed was definitely achieved during that qualifying lap, and not another lap in qualifying or perhaps even FP3?

100% last lap in Q3.

[hollus]

Assuming we are talking of this moment...
https://streamable.com/ubwi

I have asked a few times before how do teams measure their car's speed for telemetry, with no clear answers. My best guesses are engine RPM with known ratios or counts of rear axis revolutions, but to be honest, I might be missing something there. Both would carry some degree of uncertainty about the real circumference of the wheel, which can't be that trivial to determine in a rotating rubber object subject to varying centrifugal forces of up to 3000g.

Anyways, in the video, if you look at the RPM lights in his dash, it goes from 3 red lights before the finish line to 4 red lights after the finish line with a moment, right after crossing the line, where he gets 5 red lights. There is a very large chance that the 5 lights are an artifact of the measuring system or smoothing algorithm, possibly by some software system zeroing itself upon crossing the finish line.
One could expect a smooth increase in car speed from the 3 light to the 4 light period, as the Red Bull might have gained speed itself and the tow gets stronger, but there is no visible reason or change of speed differential to the Red Bull for the 5 lights moment.

I am with Juzh, this might very well be a transient measurement error, a spike in the telemetry, with no real life counterpart.

P.S. Someone (maybe someone who has done this before?) should ask Williams directly.

[SameSame]

I have asked a few times before how do teams measure their car's speed for telemetry, with no clear answers. My best guesses are engine RPM with known ratios or counts of rear axis revolutions, but to be honest, I might be missing something there. Both would carry some degree of uncertainty about the real circumference of the wheel, which can't be that trivial to determine in a rotating rubber object subject to varying centrifugal forces of up to 3000g.

OT but I know commercial cars (Mercedes in particular) have a speed sensor in the rear wheel bearing. The sensors use the Hall Effect and because the side shaft is used as a measurement reference the tyre diameter does not come into play in the speed calculation.

EDIT: Sorry that was complete blonde moment, I'm not sure how they overcome the tyre deformation aspect. Maybe use GPS data instead?

[Skippon]

Pitot tube

[Tim.Wright]

Most teams run optical slip angle sensors which are extremely accurate speed sensors.

Next up in terms off accuracy would be a gps based doppler measurement.

Wheel speeds corrected for the tyre radius would be next up. Most tyre suppliers give tables describing rolling circumference as a function of speed so they can correct for this effect. These days the state of the art is magnetic encoders rather than hall sensors because they give a much higher resolution count per revolution and are smaller and lighter for packaging.

[andylaurence]

Speed trap is positined EXACTLY at the start/finish line.

I can only conclude that you have never seen a speed trap and do not know how they function. A speed trap consists of two points of reference a distance apart. The time between those two points is measured and the average speed between them is calculated. By definition, you cannot measure speed at a point as it is a measure of distance over time, thus if the distance is zero...

[Ogami musashi]

By definition, you cannot measure speed at a point as it is a measure of distance over time, thus if the distance is zero...

A "point" (the mathematical object) has no dimensions. When you want to get rid of geometry complexity you can model an object as a "point". But the "point" you talk about is different. It is a physical point that can be always divided into two smaller points. Thus distance is always measurable (exactly or by approximation).

All of this to say, that what really matters in your remark is the window of averaging. If the two points are separated by 100m this is what we call an average speed. But if the two points are separated by 2mm, this is what we call an instant speed (and modeled by the derivative of distance over time, as time goes towards zero).

What is the distance in baku or in some other F1 circuits?

[Juzh]

Speed trap is positined EXACTLY at the start/finish line.

I can only conclude that you have never seen a speed trap and do not know how they function. A speed trap consists of two points of reference a distance apart. The time between those two points is measured and the average speed between them is calculated. By definition, you cannot measure speed at a point as it is a measure of distance over time, thus if the distance is zero...

Yes, I'm aware of that. However, I don't think it takes very long to measure a certain speed with a level of equipment available to the F1 and is a moot point in this case.

[hollus]

Thank you Tim.
Could you elaborate a bit more?
A slip angle sensor is basically a camera scanning the tarmac under it, isn't it? Can the distance to the tarmac be measured with appeopriate precision? How, a laser sensor? Is this practical during competitive running like Q3?
Also, the GPS based doppler sensor sounds awesome, is it literally working on the frequencies of the satellite signals? I was under the impression that GPS had a poor temporal resolution, so that lots of interpolation would be involved. Maybe this is wrong?
So I guess the question then is... Which of those sistems are installed in actusl competition race cars... during the competition itself?

[PlatinumZealot]

The cars have an optical ground speed sensor and they also have accelerometers in the ECU. Then there is GPS and then there is wheel speed sensors. They can choose whichever one they need that gives them the most accurate result at the time. Note the pitot tube is relative to air speed which is not all the time the ground speed of the car.

[andylaurence]

Speed trap is positined EXACTLY at the start/finish line.

I can only conclude that you have never seen a speed trap and do not know how they function. A speed trap consists of two points of reference a distance apart. The time between those two points is measured and the average speed between them is calculated. By definition, you cannot measure speed at a point as it is a measure of distance over time, thus if the distance is zero...

Yes, I'm aware of that. However, I don't think it takes very long to measure a certain speed with a level of equipment available to the F1 and is a moot point in this case.

It's really not a moot point. Let's say the trap is 1 metre long and the cars are traveling at 100m/s. The car will take 0.01 seconds to pass through that trap. Suppose the clocks are accurate to 0.001 seconds. The actual time shown for 0.01 could be anywhere between 0.0095 and 0.0105. That's ~95-105m/s or 342-378kph. Quite a range. There's timing gear that does down to 0.0001 and that would be accurate to within 1.8kph in this example. For this reason, 1m is a very short speed trap. So where is the speed trap? Your assumption that it's the start/finish line cannot be right as it's larger than a line over the track. For all we know, it's doing the measured speed on the fourth row of the grid.... or pit in. We don't have enough evidence to make an assertion.