Telemetry and Data of 2011 Monaco GP - Scarb's blog

[Paul]

Going into the tunnel, it looks like peak accel isn't achieved until 3rd gear (I believe this is correct but it would be more clear if the x-axis was time). Peak accel in 3rd gear makes sense due to increasing downforce. However, if peak accel occurs in 3rd gear then what is the purpose of 1st and 2nd? The first two ratios may have use from a standing start but why use them once you are moving? Why downshift to 1st in the hairpin if you don't even go to 100% throttle coming out of the hairpin?

That is because you don't want revs to fall below optimal range. If you took the hairpin with 3rd gear ratio revs would fall to, say, 5000rpm. Even if anti-stall doesn't kick in, flooring the throttle pedal would most certainly result in worse acceleration than 70-80% throttle in 1st gear when the revs are in optimal range. There is of course always compromise between time won with better acceleration vs. time lost shifting down and up again, something you would actually use telemetry for resolving.

[raymondu999]

Maybe none of the current cars have the traction to go flat out in 1st or 2nd. Which then raises the question why they're geared so short.

[feynman]

All I can say is many many thanks to the people who made it possible that we can see such a printout.


On the other hand it is just sad to see the reactions on this "technical forum".
Of course you can't really compare the two drivers because the red one obviously was just cruising around but that is not the main point there.
In the past we have seen users here spending lots of time with high end math to get something not even close to this. Now we get everything served on a silver plate and ignorant users complain it is just a nice picture and they can't learn anything from it. Omg it is frustrating to see how the level has dropped here.


Lots of information can be squeezed out of this picture.
When you invest some time into those raw data you can get a good idea of the car and its performance. Things like acceleration/braking/cornering performance comes to my mind. With this you can make rough assumptions about drag, downforce, engine power, gear ratios.
Also it is impressive to see the inputs of the blue driver to the car. How he applied throttle and brake etc etc.

Why don't you be quiet?

How exactly does calling other board users 'ignorant' improve the quality of the discourse? It doesn't.

It is a drawing of scruffy laps from a means-nothing practice session. You don't know aero-load, you don't know fuel load, you don't know engine map or mode, you don't know mechanical setup, you don't know engineering program, you don't know respective setup on each car, you don't know track condition or traffic status.

You don't know anything that you need to know to make any sensible statement about those two laps ... And heading off at the pass, before it got started, anyone itching to draw comparisons about the respective drivers or driving style based on a utterly context-free scrap of data pulled out a dumpster was the correct thing to do.

No-one here can draw any meaningful or substantive conclusions from that plot, it can't be done, 9/10ths of the vital pieces are missing.
It therefore remains just a pretty picture.

Anyone that has been paying attention already knew what a telemetry plot looked like, seeing another one doesn't much help anyone.
There is no significant novelty or utility that can be drawn out of that plot, and there is absolutely nothing that can be said with any seriousness or credibility based solely on that printout. You are mistaken if you believe otherwise.

[mep]

Yes you know nothing.
You want to see the micro level but fail to see the macro one.
If I remain quiet you will not learn how much can be taken out of that plot but hey it is your choice.

[spacer]

Feynman, not knowing the aero setup used in these runs does not mean the data is meaningless. Most of the info that's pubicly available only talks about very, very rough ballpark-figures.
Knowing the data behind these figures gives us the possibility to get some proper and accurate readings into the characteristics behind todays F1 cars. You're acting as if the low and high DF setups are miles apart, while in reality I think these data aren't that much apart imho, it's not like a low DF Red Bull suddenly has the equivalent DF as a formula ford car.

[raymondu999]

I don't think setup differs much between teammates nowadays; not the key stuff anyways. But what is different is the diff, the camber, the front wing, stuff that drivers tweak to look for "balance"

[Jersey Tom]

I don't think setup differs much between teammates nowadays; not the key stuff anyways. But what is different is the diff, the camber, the front wing, stuff that drivers tweak to look for "balance"

Diff, camber, and wing are pretty key IMO!

[Tim.Wright]

With Velocity and a track map, you can get Ay and Ax. That coupled with steering angle will give you already more information about the vehicle than any team would be comfortable letting out.

Tim

[bill shoe]

The data does not show the red driver being slower because he is "cruising around" or because he has major setup differences. It shows the red driver is simply not able to get into it as consistently as blue, at least not at that point in the weekend.

Red starts his braking actions more timidly, and he is not throwing the car through the narrow technical areas quite as quickly. But when he gets to the "easy parts" of the track he is going just as hard as blue. These are classic driver differences, not car differences.

Red is using the session as driver practice. He is getting a feel for the track and building himself up to it. Blue is able to use the session as car practice. He apparently does not need to spend time building up as a driver, and can immediately give the team top-level feedback about the car behavior at its limit.

Also note this data printout seems to be optimised to analyze differences in driving. It does not include many basic and obvious things you would want to see if you were analyzing the differences in vehicle dynamics. This suggests the team also sees the difference as driving rather than setup.

[Undead_Mud]

I just noticed, the red driver breaks earlier most of the lap, and although the sheet gives him a higher "base?" pressure on the break (1.23bar vs 1.07bar) the "measured?" pressure is higher.
Were they testing different settings there? Am I interpreting the two values correctly?

If the two laps are the fastest one of each driver it is rather easy to tell which team it is. If it is just a printout to compare something they tested on 1 of the 20laps or so it tells us nothing.

[feynman]

Here we go,

Red is using the session as driver practice. He is getting a feel for the track and building himself up to it. Blue is able to use the session as car practice. He apparently does not need to spend time building up as a driver, and can immediately give the team top-level feedback about the car behavior at its limit.

See, see what I mean mep ... assuming Mr Shoe has guessed the same as everyone else here has, or maybe he hasn't, does the evidence of a single plot make his emphatic sounding assertion valid? Does he convince you? Does the plot alone convince you?

Also note this data printout seems to be optimised to analyze differences in driving. It does not include many basic and obvious things you would want to see if you were analyzing the differences in vehicle dynamics. This suggests the team also sees the difference as driving rather than setup.

Of course, that is because it is the driver printout ... the team deliberately choose only to present to a driver the thinnest subset of data that is related directly to the things he is touching; the pedals he pressed, the gear he selected, the steering he turned, the wing and battery buttons he pushed ... and then overlaid the resultant time delta.
That sheet is not for the team, it for the driver to have a glance at.
(How genuinely real-world helpful it is, diving into a braking zone, is another question. I'd be curious to know how much of Hamilton's four-tenths in Nurburgring Q3 was based on a two-color inkjet versus what he feels the car to be doing right there, right now. I'm skeptical).

Race engineering, the team, doesn't much use that printout, they are using their own slices through the telemetry datasets, their own setup sheets, their own analysis of vehicle dynamics, cross referenced to pre-rolled computer simulation, factory evaluations and historical data from other sessions, atmospherics, tyre data, engine data, strain gauges and load cells, in other words the reams of paperwork and racks of fileservers, laptops and datalinks that is required by motorhomes full of experienced, professional engineers to begin to even contemplate making a meaningful statement on any given laptime, and still sometimes get it wrong ... if you were in the mood to be less verbose, that laundry list of vital information is more usually described "the stuff you don't have".

Notice, we are now three pages into this, and nothing definitive has been able to be stated about anything whatsoever, every conclusion is always a question.
Pretty picture. Pretty colors.

[bill shoe]

Undead_Mud,

There is a vertical line at the end of the lap that extends slightly higher and lower than the other vertical lines on the chart. This is the cursor. It happened to be sitting at the end of the lap when the data page was originally printed.

The parameter values under the chart (such as brake pressures) are from the moment in time indicated by the cursor (end of lap). Therefore these values correspond with the data as the drivers crossed the finish line along the pit straight.

Both drivers have approximately 1 bar of brake line pressure, which is much less than the 50-75 typically used during braking. This is logical because halfway along the straight they should not be pushing the brake pedal. The ~1 bar is either a minor calibration error or it is an absolute pressure sensor that is showing the normal 1 bar of atmospheric pressure.

[bill shoe]

feynman,

Scarbs implies the data shows the fastest lap for each driver during an entire practice session. I think this comparison does have significance. I’d prefer more data and information, but such is life. If we only posted things with 100.0% confidence then this forum would be sparse.

On a practical level— If you were an F1 engineer at Monaco, which driver would you prefer to have on your team giving you feedback during practice? Would you really say you have no preference after seeing this data? Surely you would prefer blue.

I think this data is really cool. We can actually ponder some hard info instead of only considering hypothetical/theoretical situations. The finite size of the data does not stop it from being significant and interesting.

[feynman]

There is nothing wrong with wild uninformed baseless speculation meant to fill-up an internet messageboard, nothing at all Bill ... as long as it is clearly marked as such. The problem here, in this particular case, is it's on a chart from a computer, so now it looks like science, and now all of a sudden some might get confused into thinking facile speculations and unsafe assumptions based on a fragment of data, now actually, really do, represent empirical reality. Because a waveform plot said so.

But we can finally, at long last, now say one thing for absolute certain in this thread, thanks: That if I as a hypothetical race engineer stood-up and based any sort of engineering decision on nothing more than a pair of blindingly obvious, clearly not-directly-comparable plots of two FP1 laps, I'd be fired and sent home before FP2 started.

We are all dancing round the edges, but if these two are who we all think they are, then I'd say red does know just a little bit about navigating an F1 car round Monaco, so I'd be prepared to still listen to his impressions and feedback, irrespective of how much a single sheet of paper from a track-cleaning session would like to insist otherwise.

[bill shoe]

feynman,

Am I missing something? Why does the existence of this data make you angry?

I think this data is an interesting bit of information that exists at the intersection of driving and engineering. It's rare in current F1 that we get a look at this info as opposed to talk/spin.

I agree you'd be fired.