Volkswagen Motorsport has a great challenge for this year: to lead to victory ID R Pikes Peak, its first fully electric racing car, in the famous climb of Pikes Peak, which takes place in the mountains of Colorado Springs, in the United States.
At first glance, it is clear that the VW ID R Pikes Peak has been developed for extreme conditions. Its aerodynamic look, for example, was designed to tackle the climb to the most famous peak in the world.
“The start is at an altitude of almost 2.900 meters and the finish line is 4.300 meters above sea level. There, the low air pressure translates into aerodynamic conditions different from those of a circuit on flat terrain ”, explains François-Xavier Demaison, technical director of Volkswagen Motorsport and responsible for the development of the prototype. Compared to other racing disciplines, the relatively flexible regulations give the engineers much more leeway to design the chassis and especially the rear wing of the ID R Pikes Peak.
During the 19,99-kilometer winding journey to the top, a maximum speed of about 240 km / h. This is a relatively low speed for a prototype like the ID R Pikes Peak, as it could theoretically go much faster. “For this reason, we have mainly focused on achieving optimal cornering speeds. The entire chassis is designed to generate the highest possible downforce without causing too much drag ”, says Demaison, summing up the task his team is doing.
The most visually surprising result of this strategy is the ID R Pikes Peak's apparently oversized rear wing. “At the altitude that Pikes Peak is at, the air we're driving through is on average 35% less dense. As a result, we lose 35% of downforce compared to a circuit at sea level. The huge rear wing allows us to compensate for part of this loss of downforce ", Explain Willy rampf, technical consultant of the project with years of experience in F1. "The imaginative aerodynamic development means that during the climb we will continue to achieve a maximum downforce greater than the weight of the car."
Volkswagen Motorsport used a scale model (1: 2) to test numerous variants of the Pikes Peak race car in a wind tunnel. The finishing touches were added to a life-size chassis at the Porsche development center in Weissach. "It was very beneficial to be able to use resources within the group itself", Demaison confirms.
The new components were quickly produced on a 3D printer. "We have printed around 2.000 parts, and with this system we save a lot of time", affirms the Dr. Hervé Dechipre, who, as a Volkswagen Motorsport CFD engineer, is responsible for the aerodynamics of the ID R Pikes Peak.
The electric motor in the ID R Pikes Peak needs to be cooled efficiently. However, the need for fresh air is much less than in the case of a combustion engine. Also, it is not necessary to guide the air inlet to the two electric motors that together generate 680 hp. This made it possible to reduce the size of the required intake ports on the chassis, which are always a major drawback from an aerodynamic point of view. In contrast, thin air at this altitude has a negative effect on cooling efficiency.
The simulation software provided by the technology partner ANSYS is used to calculate the ideal equilibrium. "We could not have managed it solely with the data from the wind tunnel, where it is not possible to recreate low-density air, for example", says Demaison. "The simulation was very helpful in determining the dimensions required for the cooling system."
Meanwhile, the findings from the development phase have been optimized in great detail through extensive testing. The first test on the original route in the United States is scheduled for the end of May. This is when driver Romain Dumas and the Volkswagen Motorsport team begin the final phase of their preparations for the “Pikes Peak International Hill Climb 2018”, to be held on June 24. The goal is to break the record in the class of electric prototypes which is 8m57s118 / 1000.