By Carlo Platella
Mercedes had high expectations in Texas, showing encouraging potential in Friday qualifying. The performances at the beginning of the weekend, however, did not translate into results, immediately instilling doubts that the W15 is once again the victim of unpredictable behavior and an operating window that is too narrow, with the help of the updates that arrived in Austin. However, technical director James Allison debunks this interpretation, providing a different explanation.
The news works
“Everything we measured suggests that the update package was performing as we expected,” comments the technical director. “The aerodynamic load was there and before the spins we didn’t see any ‘break’ in the flows under the car. This is it why we think the updates are good and that we will enjoy them for the rest of the year. The unpredictable behavior that led us to hit the wall an unusual number of times was due to the fact that we had set up the car too low and rigid. As a result, driveability was affected to the point of being unacceptable.”
Following Russell’s accident in qualifying and Lewis Hamilton’s in the race at the same point, the fear was that the Brackley team had run into the same problems encountered with the Spa surface. Mercedes had in fact shelved the Belgian updates after having achieved that the innovations, while increasing the overall load, had altered the aerodynamic characteristics and balance, resulting in an unpredictable car. This would not appear to be the case with the Austin package, with the handling problems linked to an aggressive choice of ground clearances.
“My impression is that we were too close to the ground”explains Allison. “These cars like to run low: the closer you get to the ground, the more you can gain time. However, if you dare too much the machine starts to behave unpleasantly. If you hit a bump badly, you risk destabilizing the car and losing the rear. When things go well, you express an excellent level of performance, but if you take a dip or a gust of wind at the wrong time, then you pay the consequences. I think we were playing our luck a little too much in terms of how low and stiff we were shooting.”
The Sprint problem
Individual episodes also added to the general problems with the set-up in Austin. For example, Allison reveals a background story that would explain Lewis Hamilton’s lack of pace during the Sprint race: “When we stripped the car after the Sprint race, in which Hamilton struggled with his handling, we discovered that one of the bearings that support one arm of the suspension had started to break. This is why the piece moved and produced that sound that Lewis heard, which was also associated with the erratic behavior of the car.”
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“It’s the main reason why Lewis felt it at the rear, even though the problem was at the front,” Allison continues. “It translates into the feeling of a dancing and unpredictable car and this had an impact on his Sprint race”. Overall, the updates would not be the cause of the poor results achieved in Austin, but the technical director does not hide that, even with a clean weekend, Mercedes could hardly have done better than sixth place.
