Wednesday 12 August 2015

Reflecting on the Spa 24 hours

A few weeks have gone by since the Spa 24 hours, and although only one round of the 2015 Blancpain Endurance Series remains, there is still a month-long wait until the cars reconvene at the Nürburgring to round off the season. I enjoyed the Spa race, partly because I find it hard not to enjoy a race over that distance, but as well because just being at Spa is to be in the company of heroes from a time when motor-racing was rather more heroic than today. I’ll admit that it wasn’t a classic race in the true sense, but it was nevertheless full of intrigue and possibilities. I would even go as far as to suggest that the outcome could have been different, had things played out just a little differently, but you’ll have to stay with me to the end of this ramble to see that.

Before the race, the wise observers were predicting a two-way battle between BMW and Audi and they weren’t wrong.

The race had a slightly bizarre feeling to it for the first few hours, as yellow flags and Safety Cars prevented a pattern from emerging, and there was no flow to the race. In the first three hours, the longest period of green flag racing was just twenty-four minutes. It was unfortunate that the first SC period split the field – providing the leading three cars with an advantage of over a minute on the rest of the field. It was also unfortunate – although surely avoidable – that the fifth SC period (lap 99 to 102) had to be carried out with a single Safety Car, when two were used for the rest of the event.

It is doubtful that these shenanigans had anything to do with the eventual outcome, given that none of the cars that were given the advantage in the early stages (the two McLarens and the Rast/Vanthoor/Winkelhock Audi) finished in the top ten anyway. What was interesting was that the final half of the race was completed with the interference of the Safety Cars for just nineteen minutes – although a further twelve minutes were spent under Full Course Yellow conditions. None of which could hide the advantage that the BMW Z4 GT3s held, although when the no. 45 car spun to a halt on its 400th lap, there were no doubt some worried faces and nervous hearts beating in the Marc VDS pits.

As it turned out, the no. 46 BMW Z4 was quicker anyway, particularly when being driven by Nicky Catsburg. In addition, the BMW spent almost four minutes less in the pits than the WRT Audi, so the victory for Bas Leinders’ crew was indeed well-deserved.

Before looking at that in any more detail though, I want to spend a moment pondering the relative merits of using Safety Cars and Full Course Yellow procedures – for both were used, as race director Alain Adam indicated might be the case in the drivers’ briefing. The total race neutralisation time was as follows:

Safety Car
No. Reason From To Time
1 #90 off at Les Combes 16:53 17:12 20 mins
2 #15 off at Les Combes 17:17 18:11 55 mins
3 #3 off at Stavelot* 18:38 19:18 41 mins
4 #75 off at Blanchimont 20:43 21:25 43 mins
5 #888 off at Blanchimont 21:48 22:00 13 mins
6 #11/#29 collide at La Source 22:20 22:42 23 mins
7 #7 off at Les Combes* 23:09 23:16 8 mins
8 #19/#21 collide at Bus Stop 23:29 23:43 15 mins
9 #50 off at Bus Stop 03:43 03:56 14 mins
10 #30 off at Stavelot 06:23 06:42 20 mins
*indicates a Safety Car period leading on directly from FCY - some may not regard this as a separate neutralisation.

Full Course Yellow
No. Reason From To Time
1 Rain 18:35 18:37 3 mins
2 #70 off at Eau Rouge 20:08 20:14 7 mins
3 #7 off at Les Combes 23:02 23:08 7 mins
4 #35 off track 01:43 01:46 4 mins
5 Debris at Eau Rouge 09:05 09:10 6 mins
6 #45 off at Rivage 10:49 10:50 2 mins
7 #50 off at Fagnes 12:48 12:50 3 mins
8 #44 stopped at Bus Stop 13:09 13:13 5 mins

(Please bear in mind that this information was compiled from my own notes and observations, so may be subject to fatigue, bad writing or just plain errors. The organisers do not publish this data in an official form, so if anyone can correct me, I am very happy to hear from you - and give you credit!)

The advantage, as Alain Adam said, with the Full Course Yellow procedure, is that it instantly reduces the speed of everyone on the race track to 80km/h – in theory at least. If marshals need to gain access to the track quickly, then surely this is the best way to achieve it. The removal of Full Course Yellow is similarly straightforward: once the incident is cleared, wave the green flag and get on with the motor race.

However, when barriers need to be made safe or replaced, and a neutralisation of longer than ten or so minutes is required, then a Safety Car is a sensible option. It seems somehow intuitive that keeping to an 80km/h speed limit for a long period of time would create issues of its own that a Safety Car avoids. From a tactical point of view it is a different matter. During a Full Course Yellow, the pits remain open throughout, so stopping will enable work to be carried out on the car while the competition is travelling at a reduced speed, enabling relative time to be gained.

When the Safety Car is out, however, although the pit entrance is open, the pit exit remains closed until the last car in the queue behind the Safety car passes – meaning that anything up to two minutes may be spent stationary waiting to be allowed out onto the track. In order to minimise this time, a well-prepared team manager will know the threshold points where his car should be, both in terms of the stint elapsed time and the car’s track position, to be able to make the decision whether to call the car into the pits (or not) whenever the Safety Car appears.

With under six hours of the race remaining, the Marc VDS BMW, in the hands of Nicky Catsburg, was leading and drawing away from Stéphane Ortelli in the WRT Audi. Pierre Dieudonné blamed tyre pressures that had not been set correctly, preventing the 1998 Le Mans winner from returning respectable lap times and losing more than two seconds per lap on average. The decision was made in the Audi pit to bring the Frenchman into the pits early in the interests of damage limitation. However, bringing him in at the end of lap 419 meant that although the remainder of the race could be completed on four stops, it seemed to me that no account was being taken of the planned stops of the no. 46 BMW, which would most likely stay out two laps longer. It might have been pivotal.

The result was that the Audi’s stops came two laps earlier than those of the BMW in the final phase of the race and critically, the BMW had a lead of just over 30s, which the Audi never looked like being able to close on sheer pace alone. However, just after the Audi had made its 22nd pit stop, at 12:45 on Sunday lunchtime, the AF Corse Ferrari of Garry Kondakov had a problem just before the Bus Stop Chicane, and a Full Course Yellow was imposed. Lucas Luhr, in the BMW, was due in for his equivalent stop on the next lap anyway, so took advantage of the fact that everyone was going slowly to make a refuelling stop and hand the car over to Markus Paltalla. The stop took 2m 04s seconds, but instead of losing the best part of a lap, when the green flag waved the BMW was still 1m 13s ahead of Nico Müller’s Audi – some 40s further ahead than it had been before.

Now just speculate, for a moment, that Dieudonné had allowed Ortelli to stay out for three further laps. This would have put his refuelling schedule one lap behind the BMW, instead of two laps ahead. And further, what if that Full Course Yellow had been called one lap later? It would have been the BMW whose pit stop would have been under green, racing conditions, and the Audi would have had the good fortune to have pitted while the BMW was travelling along at 80km/h. The forty seconds that the Audi would then have gained would have enabled it to have leapfrogged ahead of the BMW – and then what fun it would have been to watch Catsburg fighting to get back past Nico Müller in the WRT-entered Audi!

This is not to suggest that the Marc VDS BMW win had anything to do with luck – it was a well-deserved and well-executed victory; only to show how a slightly modified strategy from WRT would have led to the possibility that the race might indeed have ended on a rather different note.

Your thoughts, comments and questions are, as always, welcome.