I posted on Monday about how this weekend’s Spanish Grand Prix will be the acid test for the new rules, because the Catalunya circuit is the worst of all the F1 permanent circuits to overtake on.
I’ve since had some interesting data sent to me by Mercedes which goes into detail about what we have seen in the past in Spain in terms of overtaking and what we’ve seen this season with the DRS wing, KERS and Pirelli tyres.
We’ve already pinpointed the fast corners onto and off the pit straight as the main reason why it is so hard to pass. The exit speed from the final corner is vital to the following car, but Mercedes say that when it is one second behind, the chasing car loses approximately 7% of total downforce; when it is 0.5s behind, this rises to around 12% loss, principally on the front wing and so the car understeers and loses momentum.
However here are the stats for overtaking for the first four races of 2011, which suggest that even Barcelona will struggle to stifle the exuberant overtaking moves we’ve seen so far:
Total overtakes per race (including for damage and mistakes, faster teams
overtaking bottom three and team-mates):
‘Normal’ overtakes (ie non DRS and excluding the groups above) per race:
Australia, 12 (40% of total overtakes)
Sepang, 29 (41%)
China, 26 (29%)
Turkey, 31 (28%)
Australia, 5 (17%)
Sepang, 17 (24%)
China, 27 (30%)
Turkey, 40 (36%)
So far, average normal moves per race: 24.5
Average DRS per race: 22.25
Average overtakes per race: 75.5
Total overtakes this year so far: 302
The trends to look out for here are the increase in overtakes generally from the first race to the last, as drivers learn more about the tyres and how they work and about the DRS. But they also show that the DRS isn’t the most important factor in the surge of overtaking this year – the tyres are.
It also shows that the placing of the DRS zone is important; in Australia it wasn’t in a very good place so there were limited overtakes, whereas in Turkey its placing in the middle of a long straight made it arguably too easy.
But it also shows that most moves are taking place regardless of the DRS and this is all due to drivers being on tyres of different ages at different times.
Renault technical director James Allison made a useful observation about this yesterday, “(In Barcelona) soft tyres degrade up to 0.3 of a second per lap. This means that small variations in strategy yield very large differences in performance at different times in the race. Stopping just three laps different to another car will give nearly a 1sec/lap difference in performance. Set against that, the DRS and KERS have only a second order effect on the ease of overtaking.”
Meanwhile the FIA has tried to act to cut back on the effect of the blown diffusers, writing to teams to say that with effect from this weekend onwards, they must cut right back on the amount of exhaust gas generated on the overrun in the corners, which is something Renault engineers with Red Bull got a head start on last season and everyone has been catching up on.
It appeared a blow to the competitiveness of Red Bull, at a time when they seem to be running away with the championship, but late Tuesday night it as reported that the FIA had rowed back on the decision – for the moment due to unforseen circumstances.
Ross Brawn commented today, “The teams have all been developing their engine management systems to get the maximum advantage from the exhausts, and the FIA want to push us in a different direction now so there will be changes there.
“I’ve no idea what will be the outcome there, but it has forced all the teams to have a fresh look at what they are doing in terms of engine strategies.”
It will be discussed in Spain by engineers from the Technical Working Group and is clearly an item about which we will be hearing more.