Dakar 2007

Montero Evolution Story
The Mitsubishi Pajero/Montero Evolution was developed from the Super Production car regulations of the FIA (Federation International de lAutomobile) that came into force from 2002. The original design was the brainchild of the Design Center at Mitsubishi Motors. The car was based upon the Mitsubishi Pajero/Montero Evolution and Evo 2+2 concept cars and, like all Super Production class models, was limited to a maximum width of 2000 mm and a maximum wheel travel of 250 mm. The base model was launched at Frankfurt and a refined version was shown at the Geneva Motor Show in March 2002. The motor sport program began in June 2002, in conjunction with MMSP’s Sport Director Dominique Serieys and Technical Director Thierry Viardot. The prototype was tested extensively in the wind tunnel. The original Pajero/Montero Evolution MPR10 (MPR standing for Mitsubishis factory code name for each model) complied fully with the new regulations. Mitsubishi introduced several modifications to the original Mitsubishi Pajero/Montero Evolution after a detailed test session in Morocco in July 2003. The major development was the successful transition from a 3.5-litre V6 engine to a 4.0-litre V6 unit. FIA Cross-Country technical regulations allowed engine capacity increases in a minimum of 500 cc increments. The power plant was built and developed in Japan. It was used for the first time during the two-week test in Morocco and powered the factory cars during the 2003 UAE Desert Challenge. Modifications were also made to the suspension set-up and these were put into practice in the UAE Desert Challenge in 2003. MMSP used Brembo brakes, a 500-liter fuel tank was retained, but the minimum weight was extended from 1750 kgs to 1825 kgs as per the FIA technical regulations. The interior roll cage was reinforced around the windscreen and roof areas. Torque and throttle response was improved considerably and maximum torque increased from 36KG-M to 43 kg/m at 3500 rpm – a 19% improvement. The original Pajero/Montero Evolution engine was lowered by 100 mm and placed 300 mm back for a lower center of gravity to optimise weight distribution. Mitsubishi retained a six-speed sequential gearbox, although a new Kinetic and hydraulic anti-roll bar system was tested extensively in Morocco and used for the first time during the 2003 UAE Desert Challenge. But Mitsubishi knew that to remain competitive against improving competition, then the MPR10 would need to be further developed and improved. The MPR11 was the result of many months hard work by the team at Pont-de-Vaux and it made its competition debut in the hands of Stéphane Peterhansel and Jean-Paul Cottret during the 2004 UAE Desert Challenge. Team mates Hiroshi Masuoka and Andreas Schulz used the existing MPR10 in Dubai to enable MMSP technicians and engineers to make a comparison between the two cars in adverse conditions. The new MPR11 offered increased torque, especially at lower engine speeds, although it delivered a similar power output to the MPR10. Mitsubishi carried out exhaustive tests in Morocco with various suspension settings and there were subtle improvements to the suspension. The MPR11 benefited from improved weight distribution and had a lower center of gravity to improve handling, cornering and road holding. Peterhansel and team mate Luc Alphand went on to take first and second overall in the 2005 Dakar Rally with the MPR11 to retain the Pajero/Montero Evolution’s unbeaten record on the Dakar Rally. But Mitsubishi Motors team management knew that to stand still in terms of car development was asking for trouble and work had began even before the 2005 Dakar Rally on a revised MPR12 version of the all-conquering car. Components were tested on events during the course of the season and Mitsubishi again utilised two rigorous test sessions in Morocco in June 2005 and September 2005 to ensure that the changes and revisions to the car were worthwhile. ‘The plan was to make sure that every component on the Mitsubishi Pajero/Montero Evolution was capable of completing an entire Dakar Rally,’ admitted Technical Director Thierry Viardot. Viardot admits that the extra weight of a full tank of fuel can be critical. ‘A full tank of 500 liters weighs around 400 kgs and that is a lot of extra weight to carry at the start of a day. FIA regulations state that a car in this category must have a fuel range of 800 kms. Weight distribution is so important with this car. With the fuel tank in the back and the engine in the front, a 50:50 weight distribution is arrived at with around 250 liters of fuel in the car. ‘We completely revised components such as the differentials and the dampers with the MPR12. These suspension parts can experience staggering temperatures of up to 200 degrees Centigrade over terrain like camel grass. We have spent many hours working on damper and suspension settings and fine tuning what we have.’ New technical regulations dictated several minor changes to the new car, although Viardot admitted that the MPR12 was very similar to its predecessor from the outside. An adjustable engine inlet port was replaced by a fixed inlet port and the team was  forced to adapt the damper settings with the abolition of the Kinetic or hydraulic anti-roll bar system. Magnesium was replaced by aluminium as a base metal for the wheels, although Viardot admitted that each aluminium wheel weighed around five kilograms more than its magnesium predecessor. Work was carried out on engine performance and torque characteristics of the engine and Viardot stressed that individual set-ups were devised for differing road and stage conditions – be it hot twisty summer stages in Spain where the brakes are crucial, cool Dakar desert stages in Mauritania or the baking heat of the dunes of the United Arab Emirates, where engine and transmission cooling is critical. The MPR12 fulfilled its goal of clinching a sixth successive Dakar victory for Mitsubishi. But the MPR13 was already under development. An initial computer design was carried out by Viardots technical team in May 2005 at Pont-de-Vaux and the car was tested on gravel terrain for the first time in late June 2006 in Morocco. MMSP took one MPR12 and one MPR13 to Erfoud in Morocco for a two-week test with team drivers Stéphane Peterhansel, Luc Alphand, Joan Nani Roma, Hiroshi Masuoka and test driver Jean-Pierre Fontenay. A second test took place at the start of September 2006 using one MPR13 and each of the teams contracted Dakar drivers. A revised cooling system, new air ducting and a repositioned radiator assembly was tested at this time. The new MPR13, which features a revised space frame chassis, was designed and developed jointly between Pont-de-Vaux and Okazaki R&D Design in Japan, with extensive liaison between the two parties critical to the success of the project. There has been extensive collaboration between France and Japan on this car, said Viardot. One of the major improvements over MPR12 is the weight distribution in MPR13. The positioning of the fuel tank has been improved and spare wheel holders have been moved, leading to a lower center of gravity and balanced weight distribution. MMSP technicians have increased the comfort and safety for the crew inside the cockpit. There is slightly more leg room, the seats can be pushed back a little and headroom has been improved for tall drivers like Roma. Mitsubishi have slightly improved the approach angle of the front of the car critical when crossing dune complexes but Viardot admits that improvements to the engine have been limited by stringent FIA technical regulations. Unfortunately we are already on or near our power output limit so there are limited ways to improve the performance of the car in this area. Recent tests have confirmed that the slightly-modified engine is more responsive, courtesy of weight reduction in the valve gear train, as well as improvements to the fuel injection system. Improvements have been made in the area of brake cooling as well and MMSP carried out a test of a new BF Goodrich tire compound, which the Clermont-Ferrand based tire supplier hopes to use in competition in 2008. MPR13 also features new suspension geometry and revised suspension settings and Viardot admits that this aspect of the car is being improved all the time. The internal components of the transmission are largely unchanged, but MPR13 utilises a new casing to fit in the new chassis dimensions. The new vehicle offers additional advantages in weight reduction and improved rigidity through the replacement of the conventional sub frame with the newly-designed integral multi-tubular frame. The lowered and centred mass, when used in conjunction with a modified suspension system, makes a significant contribution to enhanced manoeuvrability and dynamic stability. The new car also features gull-wing doors. We have been integral in coming up with the ideas and specifications that we require for the new car and Japan have the expertise and facilities to carry out feasibility studies and develop the components we need. This has been especially useful on chassis design, where Japanese technicians are in a position to optimise the specification to its maximum potential. The engines are built in Japan and we assemble the transmissions using some components sourced from the United Kingdom. The remainder of the car is built at Pont-de-Vaux in collaboration with Japan. Viardot is confident that the new car is well-equipped to lead the Repsol Mitsubishi Ralliart team to a record-breaking 12th Dakar success in January and an unprecedented seventh successive victory on the worlds toughest rally.