As I write, the World Endurance Championship contenders are arriving in Japan and heading for the iconic Mt. Fuji, or more precisely, the Fuji International Speedway that sits in the shadow of Japan’s tallest peak. As usual, I will be not be there, but instead following events from the relative comfort of my spare bedroom, while commentating for www.radiolemans.com. And as usual, I’ve been trying to work out what might happen.
The first thing to say is that this is a ‘twenty-four tyre’ race – the same as Austin – i.e. the LMP1 cars have six sets of tyres for qualifying and the race.
By my reckoning, Porsche should be able to do 38 laps on a tank of fuel, which, if there are no yellow periods and it is a dry race, will mean they can do the race on six stops. This will, however, leave them with a final stint of not more than 12 laps, which they would achieve with a single, fuel only stop. This would probably be at the end of the race, but could possibly come at any point if tactics dictate, or they need to stop for some other reason.
However, since Le Mans, Porsche has chosen to do fewer laps than the expected number that comes out of my calculator. So, I actually expect them to do only 37 laps per stint - and 35 laps on the first stint, since there will be two formation laps behind the Safety Car.
I expect Audi to do 36 laps per stint. This is also a comfortable 6-stop race, but leaving a final stint of 20 laps, if they are still on the lead lap. Audi will be running an upgraded aero kit for Fuji, which should provide more downforce, but with a 1.5km straight they need more downforce and less drag (obviously). In Austin, the gap from the Porsches to the Audis was less than it was at the Nürburgring, and in the first sector there, Audi was actually quicker than Porsche. However, in the second part of the lap, which included the long backstretch, the Porsche held the advantage.
Fuji is not a circuit that plays to Audi’s strengths - indeed Audi has never won here - so it would be a surprise if they can match Porsche’s lap times, but it is important to remember that developments are constantly evolving on the cars. To stand still is to go backwards.
At Nürburgring and Austin the two Audis were running considerably less downforce than the Porsches and were quicker through the speedtraps, but slower on lap times.
I am estimating that average lap times during the race this weekend will be 1m 27.5s for Porsche. Remember, that’s an average for the whole stint: some laps will be faster and some slower. I don’t know where Audi will be - maybe 0.4s average per lap slower? So around fifteen seconds over a full stint of around fifty-four minutes.
Where I don’t think there will be any change is in Porsche’s ability to turn the car round quicker than Audi in the pits. Audi is aware of their disadvantage, and is obviously working on a solution, but it is my belief that the difference is not in procedure, but in design; and until the 2016 cars appear the Porsche will continue to exhibit its advantage in re-fuelling time - not just ahead of Audi, but of Toyota too.
As for qualifying times, I expect a two-lap average of 1m 24.5s (from Porsche, obviously). As it’s Fuji, we can possibly expect a surprise from Toyota, but I can't see how they will get below 1m 25.5s, nor how they can realistically expect to finish higher than fifth and sixth, unless those ahead have problems. That said, Toyota’s reliability has been exemplary so far this year, so if floods, earthquakes or pestilence strike Audi and Porsche, then the locals will have plenty to cheer!
In LMP2, teams are restricted to four sets of tyres per car for qualifying and the race. They will, I expect, be looking at 32/33 laps per stint. I estimate the average lap time for stint will be 1m 35.0s for the Tandy/Bird types, so they will be pitting before the LMP1 cars (but after the Rebellion/CLM). By the way, remember that it is Nick Tandy who’ll be in the KCMG Oreca in Fuji, replacing Nicolas Lapierre, who drove in Austin.
In LMP2, then, the race will consist of seven stints of roughly equal length. This means having to double-stint the Dunlop tyres three times. Another thing to bear in mind, is that the Silver driver, although only required to do 1h 15m, will probably end up doing 60 laps (1h 40m) to avoid having to make seven stops. However, as we saw in Austin, if rain or yellow flags mean an earlier stop, it might be worth making seven stops in total.
In the GTE classes, teams should be able to do the race on five stops, since their range is more than 1h 05m. Even though there is a limit of six sets of tyres for qualifying and race, the race simply isn’t long enough to allow them to use any more, so tyres (at least) will not be a problem.
The Balance of Performance adjustment made since Austin will certainly help the Aston Martins to get closer to the Manthey-entered Porsches - although it remains to be seen by how much. Porsche has to carry an extra 5kg (a family-sized bag of potatoes) compared to Austin/Nürburgring. Aston has a 0.2mm bigger diameter air restrictor - worth maybe 20bhp. In Austin, Aston was 2km/h slower through the speed trap, but around 0.5% slower in lap time. Ferrari’s BOP is unchanged.
If the Six Hours of the Circuit of the Americas turned out to be something of a whitewash for Porsche in both LMP1 and GTE-Pro, it will be much harder for them in the Six Hours of Fuji.
The circuit requires something of a compromise set-up. But here more than anywhere else, in the final part of the season, the emphasis is on having a car that is quick on the straight. The forecast (long-range, admittedly), is for a dry race. Last year (after the wash-out of 2013), there was but one period of Full Course Yellow for two and a half minutes, allowing the completion of 236 laps in six hours. A record is possible, but will require a clean race.