After months of negotiation with VW, lead sponsor Red Bull, and SCORE (the race's sanctioning body), an unorthodox but brilliant and complex alliance of German engineers, British transmission specialists, and Southern California designers and fabricators formed the nucleus of VW's formal entry into Baja desert racing. The team's primary goal in its first outing for the three-year program, as stated by Kris Nissen, VW's director of motorsport, was simply to build a race-finishing vehicle. That's no easy task for a first year design, as proven by the abysmally high attrition rate for debut concepts. SCORE's approval of the ground-breaking project was vital, as previously there had been no provision in its rules for turbodiesels. Once Bill Savage, SCORE's technical director, was convinced that there was an equitable standard for the power, torque, and fuel efficiency of Volkswagen's turbodiesel to compete with SCORE's popular American V-8s, the project commenced.
Arciero Miller's veteran lead designer and program manager, Don Tebbe, brought in famed race-chassis specialist Trevor Harris to pen the new Baja Touareg's tubular space-frame and complex but lightweight suspension. An interesting engineering enigma surrounded the project's proposed engine and drivetrain at this early point, as only the basic outlines of the engine package could be revealed at that time. Designer Ulrich Baretzky hadn't even decided on the final configuration and specifications of the engine.
Volkswagen's racing engineers never intended for the stock Touareg's iron-block V-10 to be developed for competition; instead, they borrowed one of Audi's V-12 Le Mans-winning engines. This saved time, money and, most important, weight. Compared with a gasoline-fueled engine, the turbodiesel's optimum rev-range was rather limited, so Baretzky suggested use of a six speed sequential transmission. X-trac built a new transmission that would work with the proposed mid-engine, power-forward layout. Even though most Trophy Trucks resemble the production versions from which their engines are derived, SCORE's rules permit almost any changes to the design, provided the final race vehicle generally resembles its origins. The usual safety equipment found in any serious racing chassis is required, but after that, the possibilities are limitless.
Consequently, many TTs use reverse-mounted mid-engine designs, with power going forward through highly modified GM Hydra-Matics to a special marine-derived V-drive gearbox that sends the power back to the live rear axle through a long propeller shaft with an off-set differential. The use of solid, single-piece axles with their high unsprung weight might seem unusual in a cost-no-object TT racer, but Baja terrain demands strange compromises. Tire contact with the road is what gives any racing car its speed, so Trophy Trucks, which spend much of their time in the air, need huge amounts of suspension travel to keep their rubber in contact with the ground. Delivering power to a suspension that has three-plus feet of travel requires the use of universal joints comfortable with high angularity. Long prop shafts permit this, so reverse-mounted mid-engine designs have become the norm for Baja success. Once the basic dimensions of the new tubular space-framed chassis were determined, the body design was handed off to VW's American design studio in Santa Monica, California.