Technical analysis – American and Mexican GP

The 2017 Formula 1 Championship season is slowly coming to an end, but the development race refuses to make a break. Teams are making use of the valuable track time and try out components which can be used on next year’s designs.

The McLaren team is fully concentrated on its 2018 design. The team announced earlier in autumn that it parts ways with its engine partner Honda. The collaboration which saw two dominant years at the end of the 1980’s did not want to work out in the old way. On the other front, the Woking-based squad has been working diligently on the aerodynamic performance of the MCL32 which can give and confirm ideas for the next year’s car.

McLaren introduced a new front wing in Austin which proved to be a step forward right away. The new wing features two cuts, slits on the inner section of the front wing, right at the border of the Y250 area. Two other cuts were also added to the outer section of the vanes. All four cuts aim at managing the dirty weak of the rotating front tyres. These vortex generators increase the drag, but they can very effectively drive, push the turbulent air away coming off the front tyres.

These slots work in conjuction with a new triangular vane on the bargeboards which the Peter Prodomou-led technical group introduced back during the Malaysian GP. That vane tries to calm the air down so the rear of the car can be fed with cleaner air, which boosts the efficiency of the diffuser.

The Silverstone-based team made yet another step with its bargeboards. The already very complex solution was made up by ten vertical elements which were decreased in their height a few weeks ago.

The previous bargeboards featured a strip in its lower section where a rectangular vane was sitting. The team tweaked that part and swapped it for an element which is more solid and which does not separate the horizontal and the vertical element. The upper edge was also re-sculptured and shapes now a more curved edge.

The Renault-driven Toro Rosso and the works Renault cars got the same tweak to the tail end of the engine cover for the Mexican GP which suggests that the tweak was an engine-specific reliability modification.

A gurney flap was added on to the engine cover of both designs which may have served cooling purposes which was one of the key factors at the Autodromo Hermanos Rodriguez track due to its high altitude and the consequent thinner, less-oxygen-rich air.

Renault is still working very diligently on the aerodynamic concept of its R.S.17. The French works team introduced new bargeboards in Texas, for the American Grand Prix. The Enstone-based design team modified the bargeboards of the second racing car of Renault’s latest era in Formula 1 in Spain, Azerbaijan, United Kingdom and Belgium, which shows that the element which increased in its size and consequently in its importance for this year, went through a constant evolution throughout the season.

The horizontal plate of the bargeboards were tweaked for the high-speed track of COTA. The outer edge was a single element configuration, it is now a double-element solution where the two vanes are connected by two metal fins. The pair of vanes builds a tunnel pushing air outwards. Between this double-element configuration and the middle-sized vertical element, a new mini-tunnel was added which is very much reminiscent of the bigger tunnel configuration. To stabilize this mini-sized tunnel, it is connected by one single metal fin to the middle-sized vertical vane and also to the bigger tunnel element.

The horizontal plane had previously five slots, pointing to the front of the car. The teams also tweaked them. It has now nine slots which are less curved and pointing to the outwards.
Renault is pursuing unique ways with its bargeboards. Most of the teams have bargeboards featuring Mercedes- and Force-India-like multi-element, serrated main vertical elements which separate the airflow coming off the front of the car while Renault is investing hard on the horizontal structure of the bargeboards, creating slots and tunnels.

Ferrari hardly brought any new updates for Mexico as it further evaluated its extensive upgrade package introduced in the previous American GP. This package included a new front wing with modified endplates, a new floor with re-sculptured holes in front of the rear tyres and a reprofiled diffusor with a very ambitious, aggressively shaped middle section.

The new front wing features a new fin behind the endplate. It is shaped like the trailing edge of the endplate. This fin will create more outwash ahead of the front tyre, lowering drag and tyre turbulence. Ferrari has not been too aggressive with this part of the front wing so far, but this move is a clear try to close in on Mercedes in terms of top speed which proved to be the Anglo-German team’s strength this year. Instead of creating new vortexes, this additional fin simply increase the outwash of the endplate with its shape.

The endplate itself got updated as well. The modification affected mainly its length and trailing edge to enable a good placement for the small fin. It was decreased in its length and the trailing edge has also been re-sculptured with a smaller hole between the lower edge of the endplate and the extension of the mainplane.

The new diffusor has a much more accented middle section. It features a totally level upper edge design which results in a greater expansion effect by the diffusor, raising the low pressure region behind the car. To achieve that, Ferrari had to completely redesign the mid-section of the diffusor which required extensive and long-lasting testing. This more aggressive design leads to higher downforce, but achieving this is not that linear. To achieve this increase in downforce, the airflow has to be attached to the more steeply inclined surface. It is achieved with tiny vortex generators.

The engineers also added a pair of aluminium fins to both sides of the rear crash structure.

Ferrari also introduced a modified underfloor. It has the same rearmost slot, but it features only four slots instead of five. They are, however, re-shaped and are placed with a greater angle relative to the edge of the floor. These modified slots are directed just inside the rear tyre, and as energetic flows, they will draw air into them which would otherwise collide with the wheels, while also sealing the diffusor from turbulent air flying from the tyre.