Home Formel EinsF1 F1: James Allen Strategiereport – Brasilien 2014

F1: James Allen Strategiereport – Brasilien 2014

von DonDahlmann
0 Kommentare

The Brazilian Grand Prix featured a tight strategic battle at the front between Lewis Hamilton and Nico Rosberg, with Hamilton’s chance of victory presenting itself with a strategy call.

But communication between team and driver meaning that he had to do one more lap than he anticipated before his second stop and he made a mistake on that lap, losing seven seconds and the chance to lead the race in the process. Here we will analyse that decision, the circumstances around it and assess whether he would have been in front if he had pitted after the first lap. We’ll also look at the unusual way the race turned out due to the tyre performance, more like a race from the 2012 Pirelli tyre era than a 2014 race.

Hamilton vs Rosberg

Nico Rosberg gained a vital advantage on Saturday, taking pole position by 3/100ths of a second. This gave him track position on the grid and after Hamilton didn’t try anything into the first corner, Rosberg held the lead.

F1_Brasilien_2014_04As the Pirelli soft tyres were good for only seven or eight laps and therefore not to be used again, both drivers were committed to the same strategy, which is three stops and three stints on mediums. This didn’t give the second driver any real options on strategy and meant that for a chance to win, he would have to take a risk with an overtake, as happened in similar circumstances the week before in Austin.

However, the Mercedes strategy team decided to try to create an opportunity for Hamilton, by offsetting him at the end of the second stint, after Rosberg pitted on Lap 25.
They would ask Hamilton not to pit the following lap, but a lap or two after that and to try to build a gap in order to jump him at the stop. In the end he hadn’t quite done enough on the first lap so they asked him to do another This is something they have done before; in Monaco this year for example (although a safety car ruined that plan).

Look at the table below of sector times of the crucial laps around the second stops.

Untitled2

The gap between Rosberg and Hamilton on Lap 25, before the second stops was 1.099s. The performance of the Mercedes mechanics on pit stops was variable, with 22.7 seconds their average for the race. This is the margin Hamilton needed to find.

At the end of Sector 2 of Hamilton’s first “hammer time” lap, the gap was 22.496s, which isn’t enough for him to pit and take the lead. So he went around again. His Sector 1 time for Lap 28 shows that he’s taken another 2/10ths of a second off Rosberg, so the tyres are still performing and he is now level with Rosberg. Then he makes his mistake at Turn 4 and spins.

Interlagos, Sao Paulo, Brazil.Saturday 8 November 2014.A Burrowing Owl stretches as Romain Grosjean, Lotus E22 Renault, passes.World Copyright: Charles Coates/Lotus F1.ref: Digital Image _N7T0383Hamilton said that the tyres were spent after his efforts the previous lap, so it was a mistake in that sense to make him do the extra lap, as the team has acknowledged. Had he stopped at the end of Lap 27 he would have come out of the pit lane just behind Rosberg, a few car lengths, but might have challenged him down the hill into Turn 4, for which he would have had the inside line, being on the left hand side of the circuit.

It has to be said also that Rosberg was managing the tyres very effectively, not pushing too hard on them on the first lap when they were new to avoid overheating them and shortening their life. This table shows his precise judgement. In the middle and third sectors of Lap 28 for example, having been informed that Hamilton has spun, he eases off a fraction.

Could Raikkonen have finished higher up without pit stop problem?

Ferrari’s Kimi Raikkonen was the only one of the front runners to try to do the race in two stops. On top of that he had a problem in the second stop, where he lost 4.5 seconds due to a front jack issue. So was he on the right strategy and how much did the mistake cost him?

The two-stop plan was surprising as the high track temperatures dictated three stops for the cars starting on soft tyres. Raikkonen stopped for the first time on Lap 8 along with the three stoppers, but then did a 27 lap second stint and a 36 lap final stint.

In the second stint Ferrari was dealing with its lead car, Alonso, coming under attack from the Red Bulls with Vettel pitting very aggressively on Lap 24 and undercutting the Spaniard, taking 8th place from him after he stopped on Lap 28.

GP BRASILE F1/2014At the same time Raikkonen had the possibility (if he was three stopping) to undercut Ricciardo, who was only one second ahead, but the team didn’t take it, perhaps as they were dealing with Alonso as the lead car on the road. After that had been sorted out, the moment had passed for an undercut and Raikkonen was under pressure from Hulkenberg, who was doing a sterling job having started on the medium tyres. So he stayed out and went for two stops.

In the end the tyre performance curves for Raikkonen at the end of the race show that, even without his delayed second stop, he would still have finished behind Alonso and also would have been passed by Button and Vettel anyway. Two stopping didn’t gain him anything, but it did have quite a large downside risk and he almost lost out to Hulkenberg.

And because Alonso spent six laps behind him, not running at his true pace, Raikkonen’s two-stopper actually affected Alonso’s race too. It is hard to see why Ferrari thought that the two stop plan had an upside possibility, beyond a chance safety car.

As for the jack problem, it only meant that he had more pressure from Hulkenberg, without it he would still not have been ahead of Alonso.

ubs

Das könnte Dir auch gefallen