Chinese GP tech debrief: Toro Rosso's new rear wing

Toro Rosso

It's always incredibly impressive how well the Italian team does on a limited budget, finding a performance sweet spot that gives its drivers the opportunity to get in the mix.

In China it had a new rear wing to evaluate, which featured a new upper flap that it hoped could give it a small performance lift.

The flap featured two higher cambered curvatures on the trailing edge, which undoubtedly have an impact on the way airflow moves around the entire structure.

The curvatures lead to a shorter chord length at the outboard section of the flap, and indicate how it is looking to control the vortex that is shed from the juncture between the flap and endplate. This can be destructive to downforce generation and come with a significant drag penalty.

The team is already making efforts to control this, with its serrated louvres solution on the leading edge of the endplate having an impact on the pressure gradient.

Toro Rosso STR11 rear wing, detailed view, Chinese Grand-Prix

Photo by: Giorgio Piola

Whilst the drivers both evaluated the rear wing during free practice, they decided against running it for qualifying and the race, instead reverting to the previous configuration (upper inset, above), which featured a much shallower angle of attack and only two louvres, the upper of which is detached from the leading edge of the endplate (below).

Meanwhile, during the wet sessions they also utlised their Y150 winglet (lower inset, above)

Scuderia Toro Rosso STR11 rear detail

Photo by: Giorgio Piola

Whilst not new, a fascinating detail from the STR11 that we haven't covered before, and grabbed a picture of it on the grid, is the rear suspension upright and rear brake duct juncture, which combine to make a large inlet used to cool the rear brakes.

Williams

Williams' problems continued in China, with the FW38 seemingly struggling to match the pace of some of its closest rivals, likely exacerbated by the high tyre pressures mandated by Pirelli.

As part of the performance issues faced by Williams in wet conditions in the preceding years, the team set up a wet weather working group. Much of its focus is likely to do with the behaviour of the car when switching to the wet weather compounds, which not only increase the ride height but have a different shape, temperature range and deformation rate.

This clearly has an impact on kinematics but will also have a limited effect of aero too. When we consider the efficiency of the 2014 FW36, any additional loss in downforce would always prompt a decrease in cornering performance.

Having already made changes to improve low-speed cornering capability with the FW37 in 2015, it has more changes focused on improving things for 2016 which thus far have failed to fulfil their promise.

Williams FW38 front detail

Photo by: Giorgio Piola

In China, it made changes to its front brake ducts, introducing a slot in the brake drum which was furnished with a metal insert and used for qualifying.

This was undoubtedly used to control how the heat radiates from the brakes to the wheel rim and changes the temperature and pressure within the tyre.

The team took advantage of the change in climatic conditions for the race and removed the metal insert, endeavoring to gain more thermal control over the tyres and improve braking efficiency.