Hamilton’s Data…

Well, that was an interesting thing for Hamilton to tweet…

Things that I found interesting:

(I’ll refer to everything by the distance around the lap, which is noted at the bottom.  For example, Eau Rough is at 1200m or so)

1) Hamilton gains mostly under braking, rather than in the corners (300m, 2200m, 3000m, 6700m).  I would have expected the cornering speeds to be noticeably different, but they are actually quite similar.  Hamilton can just go that little bit deeper, and brake that much harder before the wheels lock, due to the extra downforce he was running.  With each steep drop in the speed trace (second trace from the top), you can see that Hamilton is just a little later on the brakes.

2) Hamilton messed up the third corner in the “Les Combes” section (corner 9, 2600m).  He has more downforce, so should be as fast or faster, but he must have had a moment there, as his speed drops mid-corner.  Unfortunately, the data is obscured by what seems to be the steering trace.  The slight correction of the steering seems to indicate that he understeered, as he only let up on the steering rather than going into opposite lock (either that, or he has superhuman reactions that corrected a slide so quickly that he didn’t need to get to opposite lock to save it… but I doubt it!).  You can see that in that short downhill run to Bruxelles (2500-2900m), the speed traces are parallel, so he isn’t losing time because of the wing – it was just his poor exit from the corner that lost him at least a tenth or so, where he should have gained at least one or two tenths.

3) Hamilton destroys Button under braking for the final chicane… only to lose most of that advantage by killing his corner exit (6900m).  While he was able to brake much harder (note the higher brake pressure he can apply without locking up, thanks to the added downforce – bottom trace, brake pressure overlaid with throttle position – 6600m), he probably ran wide mid-chicane, ruining his line on the exit.  Because of that, Button go the better exit and clawed back much of what he lost in the braking zone.

4) Through the easy-flat corners (Eau Rouge – 1200m; Blanchimont – 6200m), they both lose the same amount of speed.  Had this been a few years ago where Eau Rouge was almost flat, the data would have been much more interesting.  While Hamilton would have had more drag, he may have had as much as a 10-15 km/h advantage exiting Radillion or Blanchimont.  At some point, Button’s speed would eclipse Hamilton’s, but Hamilton could retain an advantage.  It’s counter-intuitive, but sometimes adding downforce increases your top speed down a straight, simply because you exited the previous corner that much faster – what you lose from drag is more than outweighed by what you gain from increased exit speed.  That’s why Le Mans cars are closer to medium downforce spec now, especially with the chicanes on the Mulsanne – the corner exits are very important.

5) Neither driver can trail-brake as hard into Bruxelles (2900m), due to the downhill nature of the corner shifting the balance forward, making the rear of the car “light” and twitchy.  The braking trace shows that as they turn in, they are braking with about half as much brake pressure as the entry to Pouhon (3800m); this could be partly due to the lower speeds and therefore lower downforce, but by watching the cars through that corner, some of it has to be because they are all quite twitchy on corner entry.

6) It is worth noting that at near top speeds, there is little-to-no brake modulation, as the car has so much downforce, giving the tires so much grip that arguably the best brakes in the world still can’t lock the wheels.  Note the braking into La Source (200m) – they are mashing the brakes, and then gradually easing off the brake all the way to the apex of the corner, mostly because they are losing downforce (and therefore grip) as they slow down. To avoid locking up, they must ease off the brakes as the limit of the tires gets lower and lower with the decreasing speed.

7) Both drivers seem to be quite smooth – a testament to the McLaren.  If you look at the whole lap, looking specifically at the steering trace (third trace from the top), there are very few corrections that were made.  Each steering input, Hamilton’s correction in Les Combes aside, it’s all very deliberate and consistent – no massive opposite lock moments chasing the car through the corner.  Then looking at the throttle trace, I can’t see anywhere where they had to lift to correct for any wheelspin – clearly the McLarens are putting the power down quite well.  It would be really interesting to compare to De La Rosa’s throttle trace, where I bet his steering and throttle inputs are far more erratic, for the simple reason that the HRT has less downforce, is probably twitchy in each corner, and is not able to put the power down nearly as well – therefore poor Pedro has to wrestle the car at the limit, rather than Jenson being able to finesse the car through each of Spa’s lovely sweeping corners.

Hamilton posted the photo because he was blown away by the differences between a high downforce wing and a skinny wing, likely magnified by his disappointment of being so far off the pace.  That was obvious to me (and probably anyone that understands the trade-off between downforce and drag), but it was the few other details that I found much more interesting.

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22 thoughts on “Hamilton’s Data…

  1. Cool article, thanks.
    Would you say Hamilton’s performance was slightly poorer than Button’s? It looks like he probably made more mistakes than Button even if he had the same wing?

    • It looks like Hamilton made a mistake braking too deep for the final chicane and perhaps suffered from a touch of understeer at Les Combes, but on the whole, they look very similar from this low-resolution image. There are little bits and pieces where each one gains on the other, but nothing where you’d say that one really has an upper hand.

  2. Cool article. It’s interesting watching the Button/Hamilton quali laps side by side (on BBC iPlayer race show) and comparing them to this. Hamilton does have a small moment on the exit of Les Combes.

  3. Could someone explain in simple terms what I see on the picture? The x-axis is over the length of the track, that I got. But how do I tell which of these lines represents what? For example, on the second line from the top, who is better/faster at 1000m?
    Thanks in advance.

  4. Pingback: Hamilton twitters a verdade por trás da desculpa

  5. Reblogged this on F1 Goggles and commented:
    Well done Mr. Strachan. Another brillian piece. Imagine if all of this data was made to throw off rivals and this unintential Tweet from Hamilon was actually and cleverly intentional…

  6. At the “Les Combes” section (2), you correctly give two possible explanations for the slight correction of the steering. However, please explain why you doubt Lewis’s reaction time could be so rapid as to enable him to correct a slide quickly enough without getting to opposite lock to save it. I’ve seen quicker reaction times before amongst a certain group of men. I’d urge you to think again, these sort of blistering reactions are very possible.

    • First, there are limits to what the human body can achieve. Second, when an open wheel car twitches, it doesn’t twitch slowly. Thirdly, if it was oversteer, and he caught it that quickly, he wouldn’t have scrubbed off more than a few hundredths, rather than 1-3 tenths.

      F1 drivers are amazing, but correcting a twitch that quickly would put Hamilton not just far above average, but far above even the best in F1.

    • Yes, his speed trace is in blue, Hamilton’s is in red.

      And yes, they are close laps… but who knows which laps are being compared. It definitely wasn’t Button’s pole lap, as the delta isn’t that big – in fact, it looks like Hamilton was slightly quicker (which certainly undermines his complaints!).

      • That’s exactly what I thought. Were any of Hamilton and Button’s laps that close? I can’t believe for a second no one has noticed this until now??

    • Well, we don’t have a full time-sheet showing all of their laptimes from each session. It could be Button’s first flying lap in FP3 alongside Hamilton’s fastest Q3 lap, for all we know.

      As for it actually being Button’s data, I would say it certainly is, as there’s no way that there would be a discrepancy of that magnitude between two full-throttle runs with such similar exits out of La Source and leading up to Blanchimont – their speed traces are identical, and then slowly diverge as speed increases. It couldn’t be one lap with DRS and one without, as you can see DRS was engaged for both cars/laps through Blanchimont.

      Another interesting note is that one of the cars didn’t engage DRS from La Source to Les Combes – I assume it was Hamilton, as his top speed was significantly lower. There’s a bigger gap before braking for Les Combes than for the final chicane, despite the speeds being higher before the chicane, which leads me to believe Hamilton didn’t have his DRS open for that lap.

      So if you take the fact that they were close in lap-time over this lap, despite Hamilton keeping his DRS closed for an important part of the lap, I could see how he and his engineer could look at the data and think that it’s a good way forward for qualifying.

      • Isn’t it quite likely (or atleast possibly) Hamiltons FP3 and a Q lap? The similarity in steering for instance could point to this. Wasn’t Hamilton running the low-df-wing in FP3? Wouldn’t such a comparison actually be more relevant for evaluating if they made the car better? The only source it’s Button is actually Hamilton, and if it wasn’t McLaren would NEVER correct that in public since they want the picture buried in the first place.

      • Potentially. I just had no reason to disbelieve Hamilton; however, the similarity in steering doesn’t give me the impression that it’s one driver, for me it shows that they are two very quick drivers that are doing similar things behind the wheel to extract what they can out of the same car. Each car likes a certain style the most, and they are both likely adapting to that style.

        The thing is, F1 cars are very similar these days. The biggest difference is probably between KERS and non-KERS cars. Each driver’s trace is probably similar to each others, despite the car (perhaps excluding some of the lower teams with poorer handling where the drivers need to saw at the wheel to keep the car at the limit). It’s not like the 50′s where you had some front-engine cars racing against mid-engine cars, big cars, small cars, wildly different designs; each car these days looks and acts very similar to the others, with only minor differences between them. That said, comparing two talented drivers in the same team, where the two cars are prepared equally, and the cars handle well, you will almost always see very similar inputs between the two drivers.

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