Upgraded aero package for the Ford Fiesta Rally2

The 2022 edition of Rally Estonia saw the debut of an upgraded aero package for the Fiesta Rally2. This is the first aero modification introduced to the model born in June 2019. The upgrade consists of an updated rear wing and new wing mirrors. Here’s our review, as well as a benchmark with the other competitor’s rear wings.

Upgraded rear wing of the Ford Fiesta Rally2 – image by MSport World Rally Team

The new rear wing presents significant modifications with respect to the previous design:

1) the angle of attack of the new wing is higher,

2) endplates have been enlarged, and now act as wing supports, connected with the rear of the car, thus allowing the removal of the supports originally placed under the wing,

3) two vertical fins have been added on top of the wing.

Upgraded rear wing of the Ford Fiesta Rally2 (top) versus previous rear wing design (bottom)

The higher angle of attack (1) means that the air flowing over the wing has reduced speed, thus higher pressure. The result is that more downforce is generated. But a higher angle also means a higher front area. Air flowing over the wing finds then a bigger obstacle, that is, higher resistance (higher drag) is generated.

The bigger endplates (2) are more effective in preventing mixing of the air from above and below the wing. The result is that air speed difference between the two locations is higher than with smaller endplates (as they allow higher mixing), and the wing becomes more effective in downforce generation. Also, with the endplates supporting the wing, the center supports are no longer required. The airflow under the wing is now cleaner and faster, thus with lower pressure, which again results in higher wing efficiency.

The introduction of two vertical fins (3) over the wing, combined with the bigger endplates allows the car to take advantage of air force while the car is sideways. The impact of air over these surfaces results in pressure over the wing, which brings some extra downforce. But again, the presence of these two elements in the path of airflow generates some resistance (drag).

J.Huttunen/M.Lukka, Ford Fiesta Rally2, Rally Estonia 2022, 4th Rally2 – image by MSport World Rally Team

In summary, the new wing increases the capacity of the car to generate rear downforce, thus increasing rear grip (reducing oversteering) but at the cost of some small added drag, which might result in a small reduction in the top speed of the car.

After this modification, the latest evolutions of the Rally2 rear wings present two main trends, as shown in the image below: those with endplates replacing the central supports (Ford, VW and Škoda) against those using centered swan neck supports (Hyundai and Citroën) and smaller endplates. Also, the vertical fins that Škoda has recently removed from the Fabia RS wing, are now present in the new Fiesta rear wing. Which clearly shows that no solution is optimal.

Rear wing of the latest evolutions of Rall2 cars: (from top to bottom) Ford Fiesta, VW Polo GTI, Škoda Fabia RS, Hyundai i20 N and Citroën C3

The second modification introduced in the upgraded package of the Fiesta Rally is the new wing mirror.

J.Huttunen/M.Lukka, Ford Fiesta Rally2, Rally Estonia 2022, 4th Rally2 – image by Janne Veetõusme / Sports and Speed

The design of the new wing mirror is very similar to that of the wing mirrors introduced in the Ford Fiesta WRC in 2019, as shown in the image below.

Wing mirror of the Ford Fiesta WRC at Rally Catalunya 2019 (left) and Ford Fiesta Rally2 2022 (right) – images by llluis555 (left) and McGeehan Motorsport (right)

The purpose was the same in both cases: to reduce air resistance (drag) in that part of the car by reducing the impact of the wing mirror on the air flowing alongside the car, thanks to new support designed to leave air an open space to flow between the mirror and the car’s body. In the case of the Fiesta WRC, the purpose was also to send a cleaner airflow towards the rear side wings, but this is not the case with the Fiesta Rally2, as the rear wing has no side wings.

All the aero modifications of the Fiesta Rally2 have been done with the support of Ford Performance, which most probably includes numerical simulation (CFD) and wind tunnel testing, at the Ford Performance (Windshear) facilities located in Concord, near Charlotte, NC (USA).

Other modifications also introduced by MSport in the Fiesta Rally2 for Estonia involved the rear suspension geometry and software updates (affecting the data logger and the driver display).

The car’s debut took place in Estonia, with Jari Huttunen and Mikko Lukka at the wheel, while no official FFiesta Rally2 has been entered into the next event (Rally Finland) entry list. But the first customer unit has already been delivered, to McGeehan Motorsport for British driver David Bogie.

J.Huttunen/M.Lukka, Ford Fiesta Rally2, Rally Estonia 2022, 4th Rally2 – image by Janne Veetõusme / Sports and Speed

About Post Author

2 thoughts on “Upgraded aero package for the Ford Fiesta Rally2

  • 2022-07-26 at 03:33
    Permalink

    I almost can’t believe my eyes when I see… ahem, that PANEL GAP between the enlarged endplate and bodywork. Looks very uncharacteristically shoddy.

    On a more serious note, do you think the much shorter distance between the main chord and main bodywork on the Fiesta, compared to the other cars, is a design choice or performance-related?

    Reply
    • 2022-07-27 at 15:34
      Permalink

      You have a more detailed view on the picture by Julian Porter here.
      Regarding the distance, it is similar to the Polo. It is surely related to the higher angle of attack, which forces more air to flow under the wing, so you can bring it closer.

      Reply

Leave a Reply

Your email address will not be published. Required fields are marked *