Mitsubishi Lancer WRC04 aero design and performance

The last evolution of the successful Mitsubishi Lancer to take part in the World Rally Championship (named as WRC04 and WRC05) included one of the most developed aerodynamic designs of the moment. We make a close review of its aero design and performance, together with the Ralliart Chief Engineer Roger Estrada and one of the official drivers of the team in 2004, Kristian Sohlberg. They both gently accepted to answer our questions about the car.

The successful generation of Lancer Evo cars competing into the WR Championship as group A came to an end in 2001, once the pressure exerted by the FIA onto the Japanese manufacturer finally succeeded in convincing the team to shift to a WRC car. The new WRC Lancer, based on the Lancer Evo VII road car, was not completely a WRC car, and it proved to be slower than the group A, since its first appearance in Rally Sanremo 2001. Its poor performance prevented Mäkinen from getting his fifth title and was the reason why he left the team at the end of the season. In 2002, the arrival of new drivers (Delecour and McRae) and a new version of the car (in Finland) did not help and results never arrived, forcing the Japanese manufacturer to withdraw from the Championship, before the end of the season.

The team was determined to come back to the WR Championship with a competitive car, so the decision was to start working on the development of a brand new WRC car, instead of improving the old car. In order to better face this big challenge, the team was remodeled: Sven Quandt replaced Andrew Cowan as Team Manager, several ex-Peugeot engineers joined the team and Chief Engineer Mario Fornaris (who had replaced Bernard Lindauer) gradually lost influence in the team. On the driver’s side, Gilles and Hervé Panizzi were recruited as full-time drivers, while Gigi Galli with Guido D’Amore, Kristian Sohlberg with Kaj Lindström and Dani Solà with Xavier Amigó would drive on some selected events.

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Finland 2004, retired – picture by François Flamand – Mitsubishi Motorsport Corp.

The new car would be based on the Lancer Evo VIII, whose road car version was launched in January 2003. The main new features of this car were the introduction of the Super AYC (Active Yaw Control), a new six-speed manual transmission and engine improvements. On the aero side, the main modifications consisted of a new rear wing using carbon-reinforced plastic for both horizontal and vertical components, and an oversized front air dam cover. One year later, a special edition of the Lancer, known as Evolution VIII MR was launched to the market. The MR designation corresponding to Mitsubishi Racing, the designation traditionally reserved for Mitsubishi high-performance sports models. This model was conceived as the car to be aligned in competition as a Group N car to continue the fight against Japanese rival Subaru for dominance in the category. Features exclusive to Evolution VIII MR included new shock absorbers and a lightweight aluminum roof panel that lowered the center of gravity and reduced roll moment for better handling.

Roger Estrada, Ralliart Chief Engineer (2005-2007), Rally Catalunya 2005

The design process of the WRC04 started in early 2003, and aerodynamics was one of the areas in which most efforts were devoted. In order to know first-hand details about the aero design, we contacted Roger Estrada, who gently accepted to share with us many details of the design process. Estrada (ex-Seat Sport) joined Ralliart in 2002, as a Race and Development Engineer. He was then appointed as Principal Rally Engineer in 2004, to become Chief Engineer from 2005 to 2007. Estrada explained to us that “the aerodynamic development was carried out in the wind tunnel of Lola (a renowned 50%-scale moving ground plane wind tunnel where wind speeds of up to 230 km/h can be reached). We did not have any aero engineer in the team, so we took advantage of the big expertise on aerodynamics of the Lola team, led by the excellent Guillaume Cattelani (ex-Peugeot). We gave them our targets for the car and they did the design, based on their wide experience. They prepared a very detailed (1:3) scale model, with which they tested many different evolutions, especially rear wings and bonnets. They did measures with the car in a frontal position, as well as sideways until they reached the final design“.

The new design included some original solutions, not seen before then in any rally car. The most visible was the rear wing. As Estrada explains, “the rear wing gave us a lot of problems since the beginning. Initially, and due to marketing reasons, Mitsubishi wanted the rear wing to be located at the boot lid, as it was in the road car”. And this is one of the first alternatives that were evaluated during the wind tunnel tests, as shown in the picture below.

Mitsubishi Lancer WRC04 test model, Lola wind tunnel, 2003 – evaluation of a classic rear wing

At first sight, it seemed logical to locate the rear wing at the boot lid, to take advantage of a cleaner airflow coming from the car roof, thus increasing the efficiency in downforce generation. But there were other factors to consider, as Estrada details: “The problem in a WRC car it is not to generate downforce at the rear but at the front. The rear wing, unless you make a disastrous design, always creates a good amount of downforce. The real problem is to generate downforce at the car’s front, and this is the reason why we moved the rear wing ahead, to move the center of pressure ahead, thus increasing downforce at the front. The result was a very balanced car”.

Mitsubishi Lancer WRC04 rear wing

For this reason, the rear wing was moved ahead, close to the rear windshield end. But, as Estrada details, it was not appreciated by everybody: “although moving the wing ahead was allowed by regulations, nobody had tried before in a sedan-type car like the Lancer. Nobody had understood that it could be located there, but it was completely legal. The FIA did not want us to use it in that position neither, but the text of the regulations allowed to do it, and they had to accept it.” The rear wing was finally located right behind the rear windshield, in the internal part of the boot.

Then, due to regulations limiting the rear wing to just one wing, the lower wing had to blocked (as it had been done with the Evo V). For this reason, the lower wing was attached to the rear windshield. But this decision brought other consequences, as Estrada explains: “another problem was to open the boot. We had to spend a lot of money to design a system to open it, as the lower wing was in contact with the rear windshield“.

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Sweden 2004, retired – picture by Mitsubishi Motorsport Corp.

Both the upper wing and the lower plate included a Gurney flap to improve their efficiency.

Mitsubishi Lancer WRC05 rear wing – extracted from this video by claudiovtec

Even though this was the final configuration to be implemented in the car, other rear wing improvements were evaluated in the wind tunnel. One was the addition of (4) vertical fins, to improve the car stability and downforce generation while cornering. The picture below shows the test of this solution during a wind tunnel session.

Mitsubishi Lancer WRC04 test model with vertical fins in the rear wing, Lola wind tunnel, 2003

The full picture (below) shows the car in a test with the moving ground on (see wheels rotating), the car sideways (to fully evaluate the efficiency of the fins) and with traces of yellow paint, probably used to visualize the flow distribution over the car.

Mitsubishi Lancer WRC04 test model with vertical fins in the rear wing, Lola wind tunnel, 2003

The arm located over the windshield was connected to a sensor to measure the load (downforce) generated by the airflow under different conditions. Notice also the fidelity of the scale model in details like the bonnet design and the engine bay, to better study internal flows, or the roof scoop and the camera (which was then located beside the roof scoop in all cars).

Another area where big efforts were devoted were the fenders. The designers proposed to include very wide fenders (especially at the car’s front), while the rear was open in both front and rear fenders. Using open fenders had a double advantage: on one side, to facilitate air removal means to facilitate air entrance, allowing a higher amount of air flowing into the wheel spaces for brake cooling. Secondly, if the air removal is easier, less air accumulates under the car, and pressure (lift) is reduced. Thus, a higher grip is obtained.

The pictures below show the design of the fenders evaluated in the wind tunnel from the rear, both at the front (upper picture) and rear (lower) fenders.

Mitsubishi Lancer WRC04 test model, detail of the front fender open rear, Lola wind tunnel, 2003

Mitsubishi Lancer WRC04 test model, detail of the rear fender open rear, Lola wind tunnel, 2003

The results in the wind tunnel tests validated the design so that the team implemented these solutions into the car.

Detail of the front fender in the wind tunnel scale model (left) and in Galli/D’Amore car in Rally Monte Carlo 2004

But, again, this decision caused the team important problems, as Estrada reveals:  “Leaving the rear of the fenders open did not like to FIA, and we had a lot of problems to homologate it. It was legal, but against the spirit of regulations, according to FIA. They tried to forbid them, based on these regulations, but they could not, as we had brought regulations to the limit. From 2005, FIA decided to ban open fenders, while now is again allowed”.

G.Panizzi/H.Panizzi, Mitsubishi Lancer WRC04, Rally Cyprus 2004, retired – picture by Mitsubishi Motorsport Corp.

The third big area of improvement of the Lancer WRC04 was the front bumper, which had big benefits on the engine and front brakes cooling. “The people at Lola did a great job with the aerodynamics of the front bumper, explains Estrada. The lower part was completely oriented to improve engine cooling. That allowed us to significantly reduce the size of radiators. At the level of the front brakes, cooling was also very good, due to the two big ducts included in the front grille, that fed fresh air into the brakes. It was so effective that we never had any cooling issue in the front brakes, in opposition to the previous models, all with brake cooling issues. The design was done with radiators, intercooler and brake cooling in mind“. Cooling was also the object of multiple tests in the wind tunnel, for what great detail was paid into the design of the front bumper and bonnet in the scale model.

The final design of the front bumper included a very big air central inlet for radiator cooling, as well as for the brake cooling (see the pipe inlet on both sides of the radiators in the picture above). Also, on both sides of the front bumper, a NACA duct shape (containing the sticker of Magnetti Marelli inside) was included, to smooth the flow of air to the car sides, thus reducing the drag.

D.Solà/X.Amigó, Mitsubishi Lancer WRC04, Rally Catalunya 2004, 6th – picture by François Flamand/DPPI via Mitsubishi Motorsport Corp.

Other distinctive features of the car were the roof scoop, designed with an ellipsoidal shape, and the bonnet air vents, located on both sides of the bonnet and protected with a small lip, in order to minimize the interaction of the hot air removed from the engine bay with the main, external flow.

In summary, according to Estrada, “Even though aero modifications were more restricted than in current cars (there was nothing we could do under the car, or beside the doors), the car in 2004 was very balanced. With this car, we push aero to the limits, including solutions that had never been seen before, such as the open fenders, the rear wing location, front fenders design or the front bumper. A lot of efforts were devoted to the car front. I believe that the Ford Focus 2003 had represented a step ahead in terms of aero, and the Lancer WRC04 was even one step further“.

G.Galli/G.D’Amore, Mitsubishi Lancer WRC04, Rallye Monte Carlo 2004, retired – picture by Mitsubishi Motorsport Corp.

The first real development test of the car in a rally stage (after a short track test ) took place in mid-November. It was in Wales, at the famous Sweet Lamb stage. The first to drive the car in both tests (as usual in Ralliart) was test driver Lasse Lampi, followed by Gilles and Hervé Panizzi who had there their first contact with the car. Images from the design, build and tests held in the test track and in Wales are shown in the video below.

Video showing car assembly and first tests, by Sergey Myutel

After this first test, Gilles Panizzi declared to RallyXS magazine (nr. 13) that “the car was really equilibrated and very easy to drive“. The new car was presented to the public and press one week later, at the Essen Motorshow. New tests took place in December and January in the South of France, Spain (Riudecanyes) and Sweden, both for the development and for the preparation of the coming events.

G.Panizzi/H.Panizzi, Mitsubishi Lancer WRC04, 2004 pre-season test – picture by Mitsubishi Motorsport Corp.

For the year 2004, the team philosophy was to treat it as a learning year, to creates a car and a driving team ready for success in the years ahead. Two cars were aligned in the 2004 Rally Monte Carlo, for Panizzi/Panizzi and Galli/D’Amore. Before starting the event, Gilles Panizzi already announced that the car was not sufficiently prepared: “I am very happy about the car, the engineering, the mechanics and the spirit in the team, but this car was only born in November and two months to prepare for a new season is not so much. We need more time; maybe one season before we become completely competitive. But I am very confident in the team, I like the car, the balance is good and we all work well together, but two months for the Monte Carlo…we are not ready yet; we have to be patient and we need time to improve.

G.Panizzi/H.Panizzi, Mitsubishi Lancer WRC04, Rallye Monte Carlo 2004, 6th – picture by Mitsubishi Motorsport Corp.

Not surprisingly, the team participation at the Monte Carlo was rather a development test than a proper rally. The car behaviour improved stage after stage, allowing the drivers to set some interesting stage times: Galli/D’Amore were fourth at the SS3 Selonnet-Brézier (22,6 km) just two seconds away from stage winners Martin/Park (but were forced to retire due to an accident two stages later) while the Panizzi duo set five stage times in the top five, to finish the rally in the sixth position.

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Sweden 2004, retired – picture by François Baudin – Mitsubishi Motorsport Corp.

To know a little better about the performance of the car, especially on the aero side, we contacted the 2004 Mitsubishi Official driver Kristian Sohlberg, who drove the car in five events that year, starting in Sweden.

Like Panizzi, a late schedule is one of the first problems of the car Sohlberg mentions: “the car itself had a good chassis, but the team tried to do a miracle with the development work and testing starting so late, that it was never going to work, unfortunately. It would have been a good car with the correct amount of testing and development plan.”

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Sweden 2004, retired – picture by Mitsubishi Motorsport Corp.

In Sweden, both Sohlberg and Panizzi cars had to retire during the first day due to reliability issues (transmission). It is usual for a new car to suffer from reliability issues during the first events. But, in the case of the Lancer WRC04, solving them took much longer, as Sohlberg explains: “We had so many issues with reliability through the whole year that aero was not the main point at the time”.

Suspension issues also played an important role, as Sohlberg detailed when we asked him about the rear wing: “It’s hard to really analyze this (the car behaviour) as the issues we had with setup/dampers, in general, were so big that the advantage or disadvantage of the rear wing was not very clear for me”. Also, engine and electrical problems caused different retirements that year, especially during the gravel events in the first part of the season.

Reliability also affected the aero parts, as Estrada points out: “In terms of aero, the car performed very well, but the problem was the reliability of the aero parts, which we lost easily during the stages“.

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Cyprus 2004, retired – picture by François Baudin – Mitsubishi Motorsport Corp.

In spite of that, the hottest events showed some of the benefits of the aero design, as Sohlberg reports: “The cooling was working Ok even in harder conditions. In Cyprus we had an OK start to the rally but then a sumpguard issue made our life difficult as a quick release pin came loose and we could not attach the guard again. One of the strange issues we had…. But cooling was working Ok”.

K.Sohlberg/K.Lindström, Mitsubishi Lancer WRC04, Rally Argentina 2004, retired – picture by François Flamand- Mitsubishi Motorsport Corp.

Better results started to come in Argentina, where the Panizzi duo finished in the fifth position, while Sohlberg/Lindström were able to set consistent stage times on the first day, inside the top 7, before retiring due to gearbox problems. In their home event, the Finnish duo was driving at a similar pace, but were also forced to retire. According to Sohlberg, “Finland was my mistake, but it was also something that the car’s suspension was lacking… I think it was more of the combination of lacking aero in rear and dampers in handling small bumps in high-speed sections”. Could this be a potential side effect of the advanced location rear wing location (a lack of aero in high-speed sections)?

D.Solà/X.Amigó, Mitsubishi Lancer WRC04, Rallye Deutschland 2004, retired – picture by Alex Guillaumot – Mitsubishi Motorsport Corp.

After Rally Deutschland, and due to the poor results in the previous events, the team decided to make a break on some events, in order to concentrate solely on testing for 2005. The initial plan was to take part in two more events before the end of the season, but, in the end, the team only participated in the Rally Catalunya. In the meantime, Isao Torii had replaced Sven Quandt as Team Manager.

The break paid off, as in Catalunya, Solà/Amigó and Galli/D’Amore finished in 6th and 7th position, respectively, with the Panizzi duo in 12th. It was the first time that all Mitsubishi cars were able to reach the end on that season and a confirmation of the good progress on tarmac.

D.Solà/X.Amigó, Mitsubishi Lancer WRC04, Rally Catalunya 2004, 6th – picture by Miquel Rovira / RACC

For 2005, the modifications introduced by FIA in the technical regulations forced the team to modify the car, which was named as Lancer WRC05. Firstly, the open fenders were banned, and the team had to design closed fenders, losing the advantage of the original design. The picture below shows the car (on top) with open fenders in 2004 and with closed fenders (at the bottom) in 2005.

G.Galli/G.D’Amore, Mitsubishi Lancer WRC04, Rally Catalunya (up) and Mitsubishi Lancer WRC05, Rallye Deutschland 2005 (down) – pictures by Mitsubishi Motorsport Corp.

Secondly, the width of the cars was increased by 30 mm (from 1770 to 1800 mm). The result was a bigger front area, but this was a minor impact, according to Roger Estrada: “The increase in width contributed significantly to improve the car performance, especially when cornering. In terms of aero, it was a disadvantage (higher front area means higher drag). But there were other sources of drag more important (such as the rear wing), and aerodynamics were so limited then, that the increase in drag was irrelevant. With the current WRC cars, it would have been different, as they are so aerodynamically developed that the influence would have been much higher now“.

On the driver’s side, Harri Rovanperä and Risto Pietiläinen joined the team, together with the Panizzi duo and Galli/D’Amore, while the contracts of Solà/Amigó and Sohlberg/Lindström were not renewed.

H.Rovanperä/R.Pietiläinen, Mitsubishi Lancer WRC05, Rallye Deutschland 2005, 10th – picture by Mitsubishi Motorsport Corp.

In 2005, once most of the reliability problems had been solved, the results significantly improved. The new season started with a podium (the first for the car) in Monte Carlo as Panizzi brothers finished in the third position. The development tests continued, in spite of the budget restrictions and the departure of Mario Fornaris from the team, who was replaced by Yasuo Tanaka as Technical Manager.

G.Panizzi/H.Panizzi, Mitsubishi Lancer WRC05, Rallye Monte Carlo 2005, 3rd – picture by François Baudin / DPPI – Mitsubishi Motorsport Corp.

Some other top-5 positions were reached by Rovanperä/Pietiläinen in México, Argentina, Wales and Japan, and by Galli/D’Amore in Germany. The season ended with another great result, as Rovanperä and Pietiläinen finished in the second position in Australia, with Galli/D’Amore 5th.

H.Rovanperä/R.Pietiläinen, Mitsubishi Lancer WRC04, Rally Australia 2004, 2nd – picture by Mitsubishi Motorsport Corp.

But the car still suffered from some of the same issues as in 2004, so new development tests were carried out in Spain in November 2005 to solve them. As Roger Estrada explains: “At the end of 2005 season we finally could solve the issues we had identified since 2004, including suspension (geometry and shock absorbers) and an improved turbo, and the car performance significantly improved. Some days later, Mitsubishi decided to withdraw from the Championship. I’m convinced that, with these modifications, the car would have become a winning car, but unfortunately, we could not demonstrate it“.

G.Galli/G.D’Amore, Mitsubishi Lancer WRC05, Rally Catalunya 2005, retired

During 2006, Ralliart gave support to some customer cars, and still good results were obtained, as the third and fourth positions of Carlsson/Holmstrand and the Galli/Bernacchini in  Sweden or the 5th position of Välimäki/Kalliolepo in Sardegna.

D.Carlsson/B.Holmstrand, Mistubishi Lancer WRC05, Rally Sweden 2006, 3rd – picture by Petr Lusk – ewrc-results.com

Also, in 2007 the car made some appearances in the WRC, like that of Sohlberg/Pietiläinen in Rally Finland 2007. This gave the Finn driver the chance to evaluate the progress of the car since he had last driven it back in 2004: “The car had changed a lot from 2004, the semigearbox was working and the engine was very much improved, also the whole package had changed, which proves my initial feeling that the chassis was a very good one, even if slightly big”.

K.Sohlberg/R.Pietiläinen, Mitsubishi Lancer WRC05, Rally Finland 2005, retired – picture by Petr Sagner – ewrc-results.com

Since early 2006, the team efforts were mainly focused on the development of the new evolution of a WRC car. Based on the Lancer Evo X, it was expected to be aligned in 2007. However, Mitsubishi took the decision to stop the development when only the drawings were available, and no car was ever built. And, still today, no other official Mitsubishi car has participated in any event of the World Rally Championship. Will the new 2022 regulations contribute to breaking this long absence?

All results extracted from the Ewrc-results database.

This article belongs to the series of articles we have devoted to the brilliant Mitsubishi Lancer Evo saga:

  1. Mitsubishi Lancer Evo and Tommi Makinen mastered the WRC in the 90s
  2. Mitsubishi Lancer Evo IV and V or how a group A car could beat the WRC
  3. Mitsubishi Lancer Evo VI and TME: last success of the Mitsubishi and Mäkinen combination

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