James Key (Technical Director):
The Baku circuit presented everyone with more of a challenge than any new track I can think of over the past ten years. It's a street circuit where you have to be very accurate as there are no run-off areas, but it's also a mix of high speed long straights and Monaco-like twisty sections and as always in these circumstances, very low grip on fresh new tarmac. Although you do plenty of simulation work beforehand, with a circuit as difficult as this you can only make rough estimates and only when you start running you really learn what is needed and that was a major feature of this weekend.
When we first went on track we were surprised at just how low were the grip levels, although we didn't suffer too much with getting the tyres to work. However, we were aware that temperatures were due to get much hotter, so we were concerned about any potential overheating issues with the tyres. The grip was incredibly low and when you only have a wall separating you from either carrying on with the session or repairing a lot of expensive damage, you have to be very careful. We made a lot of adjustments to the cars to counter the low grip and consequently, lap times were slow on this very technical circuit. But over the course of Friday, track evolution was high and by FP2 we got a better idea of what was needed. One key area was working out the wing levels, as the track is half Monaco, half Monza. So in general, this was a good first day, although we were slightly disappointed with our one-lap performance.
We had a better idea what to do for FP3 and we managed to improve the single lap pace through changes to the set-up. However, this is another circuit where, like Montreal the previous week, we were aware we would suffer from the lack of engine development on our 2015-spec power unit compared to others. Therefore, our car set-up for Baku was always going to be a big compromise. In FP3, we were much happier with our one lap pace. In qualifying, even though this is a very long track, traffic problems were quite severe, because there is not much space for people to move out of the way and there was quite a big speed differential between the cars. Therefore, traffic management was important. In Q1, we also noticed a further big step forward in track condition. This meant that multiple laps on one set of tyres was still delivering performance. We tried to do that but with other teams going out on fresh tyres towards the end, we had to play it safe and sent both drivers out for a single lap towards the end on fresh tyres which put them both well up the order. In Q2, unfortunately on this tough track, Carlos failed to get his quickest lap together and he ended up in P13, but Daniil managed to do a competitive time to get into the top ten. In Q3, he went on to be seventh fastest, moving up one place on the grid after Perez's gearbox change penalty.
Carlos needed a gearbox change and so had to start a long way down the order. This turned out to be an afternoon from which it is important to learn something, but at the same time, one you would rather forget. Before the start, it was hard to know if we would have a race of attrition with only a handful of cars finishing, or if it would be much cleaner. Everyone adopted a more conservative race having watched the exciting GP2 races! With Carlos, we had a lot of ground to make up, so we planned to stop him early, put him out in clean air on the Soft tyre and see how far we could go, a choice which in theory could have seen him go to the end on one stop. We were not sure what to expect, as temperatures were extremely high on Sunday.
With Daniil it was a case of racing the guys around him and tuning our strategy – one or two stops – accordingly. The plan worked for Carlos, but Daniil immediately had a problem with temperatures, which affected our use of the Power Unit, so that he did not have good top speed. That's why he lost so many places in the early stages. Then both cars suffered with the same suspension issue, in Carlos' case when he looked to have fought his way from the back into a points-scoring position. We ended up with a strange failure on both cars caused by the rear suspension jamming itself at the end of the long straight. We had never seen this before, not even earlier that weekend. We are currently investigating the exact causes.