Wednesday, 30 October 2013

Racing for Points in the Far East

It was a great shame that the rain made racing impossible at the most recent round of the World Endurance Championship at Fuji, Japan. After practice and qualifying, a close race was truly in prospect between Audi and Toyota, and I must admit, anticipation was high.

Possibly out of frustration, I was ready to rant about the decision to award half-points: surely a race in which no overtaking is allowed should not be counted as a race at all? It made no sense to me that results should be issued, whether they included stoppage time or not. Luckily no points are awarded for fastest lap in the WEC! And I’m glad I didn’t make the trip all the way there to see just 16 laps (or was it 17?) behind the safety car.

But the passage of a couple of weeks to think about it has cooled my blood a little and there are plenty of reasons to justify the decisions made, and overall, I believe they were the correct ones.

Inevitably, practice and qualifying go part of the way to defining how a race will pan out, and it seems right that those who went well in qualifying should be rewarded. Also, it would have been wrong, in my view, if the errors (or misfortunes) that led to two of the top three LMP1 qualifiers falling back down the order had gone unpunished. Awarding half points achieved both of those things, at least as far as P1 was concerned.

So even if there were some unhappy customers after Fuji – and you never have to go far to find some disgruntled punters – I think the organisers, stewards and other officials did as good a job as could be done in the circumstances.

But the aim of this column is to look forward to round seven of the championship at Shanghai, China, not to look back at round six. And on that note, here are some predictions for how things might go. As usual, my starting point is to suppose a dry race with no safety car periods, which, as we have seen, is not necessarily a likely scenario, but is the best place to start.

In order to do a six hour race on seven pit stops, it is necessary to have 44 minutes fuel autonomy. In other words, you have to be able to drive for 44 minutes on a single tank. On the assumption that it takes a minute to drive down the pit lane and refuel (actually at Shanghai it takes 55 seconds), then you are out of the pit and running again after 45 minutes. Of course, three-quarters of an hour is exactly one-eighth of the race, so provides a perfect seven-stop strategy.

Of course, there are two slight wrinkles in the perfect strategy: the first being that you have to complete a formation lap at the beginning of the race – actually two laps, since you need to drive to the grid and you are not allowed to refuel on the grid – this means that the first stint is always a bit shorter; and second, the race runs to the end of the lap you’re on, after six hours has elapsed. However, since not every pit stop is ‘fuel-only’, the longer stops to change tyres and driver still means that 44 minutes is sufficient to make seven pit stops possible in a six-hour race.

The table shows the fuel autonomy figures required for other strategies:
No. of Stops Fuel Autonomy (time)
7 44m
6 51m
5 59m
4 1h 11m

My prediction is that Audi will be able to achieve 24 laps on a tank, and the average race lap time will be of the order of 1m 50s. This gives them exactly 44 minutes autonomy, so they will certainly be planning a seven-stop race (until the safety car appears). Someone at Ingolstadt obviously has done the same calculations as me.

Toyota has proved this year that it is able to go further on its fuel than Audi (partially helped by an increased tank size). To save an additional stop, though, they need to achieve an additional seven minutes, according to our table above. My calculation is that they will manage 27 laps, but even if they are a second a lap slower than Audi (which I doubt), they will still not be able to manage 51 minutes, so a seventh ‘splash and dash’ stop will also be necessary for Toyota.

However, it is entirely possible (and not entirely unlikely) that the safety car will slow the pace sufficiently to enable Toyota to do the race on six stops, but Audi will still need seven.

Regardless of the number of pit-stops made, the two factors that are most likely to affect the outcome of the race are: one, the pace differential between Audi and Toyota in average race lap time; and two, the position of the cars if and when the safety car is deployed.

At Fuji, the Toyotas were within a couple of tenths of a second per lap of the Audi times in both Free Practice and Qualifying, and I was expecting similar in the race. If the safety car enables Toyota to save a pit stop, and if it is deployed at a time favourable to Toyota (in other words, when Audi and Toyota have completed the same number of pit stops), then Audi will have to lap three-tenths faster per lap to ensure it doesn’t lose.

On the other hand, if we can survive the whole race without the need of the safety car, then even if the Toyotas can lap within a tenth of the Audis, I can’t see how they can prevent Audi from winning.

A third factor, which I do not expect to play a role, hence I have not mentioned it (until now) is the possibility that Toyota is able to double stint its tyres and Audi is not. This would give Toyota an advantage, over the race distance, of up to a minute: certainly enough to compensate for a lap time disadvantage of half a second per lap. Remember though, that last year’s race at Shanghai saw only Rebellion, from LMP1, double stinting the tyres.

In conclusion, although the gap between Audi and Toyota is reducing, I can find no evidence that Toyota is quicker. In which case, Toyota needs some kind of help, in the shape of the safety car, better tyre wear or Audi unreliability, to be able to win. But these are the unknowns that make endurance racing interesting. There are many things that can and do go wrong in a six hour race. Just let us hope that it is a proper race!


  1. Top analysis once again Paul, and given that, I do not doubt your conclusion. Having just had a look at the longer range forecast (for what it is worth) it looks like the weather could also play a hand. A few showers I guess will only favour the 'green' quattro effect.. Look forward to your coverage, and as its the last WEC event of the year will be making a special effort to be up for the duration. UK start-time 3am I believe !! Best, Nick.

  2. Of course I should have added that with the weather comes slips, trips, stumbles and falls, so could be the great randomiser we need to spice up the final race of the season. Bring it on !