Are the current WRC cars’ aero devices really original?

One of the main characteristics of the current WRC car generation is the use of multiple aero devices in every corner of the vehicle, with the main purpose of generating downforce at the minimal drag cost. Dive planes, fender vents, rear diffuser and rear wings with side winglets were introduced by all or most of the teams. The question is: were these solutions innovative in rallying, or were they inspired by previous designs? We try to get a complete answer in the following lines, with the aid of multiple images from all rally eras.

Starting from the front end, current WRC cars include prominent front splitters to limit the airflow under the car, while generating downforce thanks to the air impacting on the upper side of this device, This is not new in rallying, as different manufacturers have proposed different solutions to get the same effect. Here are two of our favorites, from two cars which appeared at the same time.

One of the first cars to use a front splitter was the Lancia Rally 037. The purpose was to reduce the amount of air flowing under the car to decrease pressure, thus generating higher downforce by the higher pressure difference.

H.Toivonen/J.Piironen, Lancia Rally 037, Rallye Monte Carlo 1985, 6th – picture from Mondiali Rally blog

Soon after, Lancia introduced a more prominent, rounded front splitter in the front end of the Delta S4, with the same purpose.

H.Toivonen/N.Wilson, Lancia Delta S4, RAC Rally 1985, 1st – picture by Martini Lancia

Also in 1985, and thanks to the technological support from F1 team Williams Engineering, Austin included an F1 front wing in the Metro 6R4. Starting from one of the wings the team used in F1, they developed an original solution that has never been replicated in any other rally car, and which still constitutes one of the symbols of such an iconic car.

T.Pond/R.Arthur, Metro 6R4, 1986 RAC Rally, 6th, picture by LAT Photographic

Dive planes are very common in circuit racecars, but not so common in rallying. The first (and probably) unique attempt to use dive planes was done by Peugeot in 1985, when they added two plastic planes on the sides of the front bumper of the Peugeot Turbo 16 Evo 2.

T.Salonen/S.Harjanne, Peugeot 205 Turbo 16 E2, Rally Sanremo 1985, 2nd – picture by fotosport –

The initial design had to be reviewed, as it was not very effective due to the too thin material used. Also, a side lip was added, similar to what Toyota or Hyundai initially did in the current WRC cars.

J.Kankkunen/J.Piironen, Peugeot 205 Turbo 16 E2, Rally Acropolis 1986, 1st

The use of the front fender for generating downforce is not new. Audi developed such a solution in the Quattro Sport E2. They also included a (black) lip on the exterior, to better channel air towards rear wing.

S.Blomqvist/B.Cederberg, Audi Quattro Sport E2, Rally Argentina 1985, ret.

Roof scoops have been present in rally cars from the 80s, with multiple solutions of different complexity. One of our favorites, by its simplicity (not sure about their efficiency), is the roof scoop Lancia designed for the 037 Rally car.

H.Toivonen/j.Piironen, Lancia Rally 037, 1984 1000 Lakes Rally, 3rd, picture by LAT Photographic

Much more original was the introduction of cockpit vents in the rear part of the roof. Such an innovative solution was introduced also by Lancia some years later, in the Lancia Delta HF 4WD group A in 1987.

J.Kankkunen/J.Piironen, Lancia Delta HF 4WD, Rally Acropolis 1987, 2nd

Current WRC cars include huge side skirts to prevent air from flowing under the car. Such a solution was initially introduced by Peugeot in 1986, although those were vertical skirts. At the end of the Sanremo Rally, the stewards excluded all Peugeots due to considering the skirts illegal. Peugeot appealed and FISA finally decided that the exclusion had been illegal, for what the results of the Italian event were not considered in the Championship classification, and Kankkunen/Piironen (Peugeot) were crowned as World Champions, instead of Alen/Kivimakki, (Lancia).

T.Salonen/S.Harjanne, Peugeot 205 T16 Evo2, Rally Sanremo 1986, ret. – picture by fotosport –

Once regulations changed in 1997, side skirts were included and developed in some of the first WRC cars. They grew in size with every car generation and reached a top size in cars such as the iconic Mitsubishi Lancer Evo V.

T.Mäkinen/R.Mannisenmaki, Mitsubishi Lancer Evo V, Rally Finland 1998, 1st – picture by Jan Marek –

Wheel (rim) design is currently the object of study by all teams, leading to new, optimized designs (more reliable and aero efficient) such as the new wheels OZ designed for the Toyota Yaris WRC in 2019. But again this is not new in rallying: one clear example is the modified rims Peugeot introduced in the Tour de Corse in 1986 to improve the performance of the Peugeot Turbo 16 Evo2, as shown in the picture below, in one of the two events where Michéle Mouton and Fabrizia Pons took part driving a Peugeot (the other being the Monte Carlo’86).

M.Mouton/F.Pons, Peugeot 205 Turbo 16 E2, Tour de Corse 1986, ret. – picture by

Note that the Peugeot also included a kind of exhaust blown diffuser, with the exhaust pipe exit located at the center.

The rear wing constitutes one of the symbols of the current WRC car generation. But they have been widely used in rallying since the late 60s, when the Porsche 9xX included a small lip on the rear, acting as a spoiler. From all the different rear spoilers and wings seen since then, our choice is one of the most developed and complex: the magnificent rear wing of the Audi Quattro E2, with two small wing prolongations on the side of the main wing, similar to the winglets used in current WRC cars.

The configuration seen in the picture was only used in 1985 Rallyes of Argentina and 1000 lakes. Since the next event (Sanremo), the side wings were modified to be just a prolongation of the central wing, Unfortunately, Audi withdrew from the World Rally Championship some months later, and such an impressive car could only take part in six events. But for years, this will be the most known rally rear wing, and even today there are many comparatives between group B cars and current WRC cars, as they both represent the top of aerodynamics in rallying, with the permission of the 1997 WRC cars.

A.Bettega/S.Cresto, Lancia Rally 037, Tour de Corse 1984, 7th – picture from Rallyeteca

Rear-wheel fender vents have been the object of intense studies and development in the current WRC. However, more simple designs can be found in cars of the 80s, such as the Lancia Rally 037, on both sides of the car plate, in the rear bumper.

In summary, most of the solutions of the current WRC cars have their origin in the group B era. That’s why we consider group B years as the first golden ear of aerodynamics in rallying. The current is the third, while the second is the WRC car generated with the change in regulations FIA introduced in 1997.

After such a review, the reader will note that there are some current devices that have not been mentioned, such as the wheel diffusers, front fender vents or front fenders winglets. The reason is that they have not been previously used in any rally car (as far as we are aware of). So the answer to our initial question is: Yes, most of the current devices have been previously used in older rally cars, while some (those mentioned in the previous lines) are completely new in rallying….unless we miss anyone. If so, we will really appreciate if you can send us any info on them and we will update it.

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4 thoughts on “Are the current WRC cars’ aero devices really original?

  • 2020-01-08 at 14:39

    you clearly have no background in aerodynamics… it’s just some fan rambling
    at least the pictures are nice

  • 2020-02-10 at 09:26

    I’ll read the articles later, but I spotted the mis-captioning of Bettega’s 037 in Corsica: this is the “non-evo” version of early 1982, whereas 1984’s Evo2 does without the rear valance and only uses mudflaps behind the rear wheels.

    • 2020-02-10 at 17:37

      Good point, thanks. In any case, it is still valuable for illustrating how some solutions were already used in the early 80s.


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