25 days until the 2009 Dakar Rally in Argentina and Chile

Off to altitude training: Race Touareg completes test in environmental chamber

Wolfsburg (09 December 2008). The Andes instead of the Sahara: before the Dakar Rally, which after 29 editions through Africa will lead through South America for the first time in January, the Volkswagen Race Touareg 2 has completed an unusual training camp. In the Volkswagen Group's altitude environmental test chamber in Wolfsburg the cross-country rally prototype was subjected to several series of tests simulating the unique climatic conditions of the world's toughest rally in Argentina and Chile. The objective of the complex tests was to adapt engine electronics control to the extreme altitudes of up to 4,700 metres above mean sea level during the 9,578-kilometre endurance test for man and material. This way, the engineers want to assure the durability as well as optimum performance of the 280-hp TDI turbo diesel engines during the crossings of the Andes. At the "Dakar", which starts in Buenos Aires on 03 January and finishes at the same location on 18 January, Volkswagen fields four Race Touareg vehicles.

"Not only for the drivers and co-drivers the air will be thin when crossing the Andes," says Volkswagen Motorsport Director Kris Nissen. "The extreme altitude demands perfect preparation for these conditions, both of man and material. The tests in the altitude environmental chamber in Wolfsburg were an important step in our preparations for the 'Dakar' - and the close collaboration between motorsport and the engineers from the production side of the house proved to be highly valuable yet again."

Thin air in the Andes: simulation of extreme altitudes

While preparing for the demands of the upcoming Dakar Rally, the engineers were able to draw on leading-edge technology available within the Volkswagen Group: in the altitude environmental test chamber conditions in the Andes in terms of temperature, humidity and ambient pressure were simulated along with simultaneous modelling of the air flow over the vehicle at varying speeds on the integrated chassis roller dynamometer. During the tests spanning several days a special focus was put on an innovative component of the 2.5-litre TDI powerplant: for the action of the two-stage turbocharger a program map for different altitudes was worked out and refined to prevent possible over-revving due to the thinner air. During the Dakar Rally a sensor continually determines the current altitude; and the engine's electronic control unit, among other things, controls the maximum speed of the complex turbocharger system. During the test, conditions at altitudes above 4,000 metres were simulated and the program maps for even more extreme conditions were determined by means of calculations based on the data obtained. In addition to durability, the test series focused on optimised engine output as well: after all, the Volkswagen engineers anticipate a power loss of more than 20 per cent in the most extreme conditions of the Andes.

-credit: vw