The Audi R8 LMS GT4 stands for production-based racing. The race car that is directly derived from the road-approved Audi R8 Coupé V10 is powerful, offers a high level of safety yet remains economical in terms of purchasing cost and cost of ownership. It is the ideal race car for amateur campaigners, completely in line with the spirit of the GT4 regulations carrying on a great sports car tradition in which fascinating road-going sports cars were a popular base for GT racing more than half a century ago.
A veritable powerhouse: The V10 engine of the new Audi R8 LMS GT4 can deliver up to 364 kW (495 hp) – depending on the applicable Balance of Performance rating that is designed to ensure fair competition between all race cars. The 5.2-liter naturally aspirated engine is produced by Audi Hungaria at the Győr location and only receives a new exhaust system, the restrictor plate prescribed by the regulations and modified mapping of the production-level electronic control unit (ECU). Audi Sporthas previously demonstrated the durability of this unit, which requires maintenance only after 10,000 kilometers and rebuild after 20,000 kilometers, in the GT3 model. Afterwards, many customers complete additional cycles in racing operation.
As quattro four-wheel drive is prohibited in the GT4 class, Audi Sport utilizes a 7-speed double-clutch transmission combined with rear-wheel drive. Two electrohydraulically operated wet-type multi-plate clutches ensure shortest shifting events without tractive force interruption. A mechanical limited slip differential is used on the rear axle.
The suspension of the road-going version featuring double wishbones on all four wheels offers perfect prerequisites for racing. Rebound and compression adjustable racing-specific dampers and springs, as well as adjustable stabilizers, complete the suspension system. A new steel disc braking system with modified brake calipers in combination with the production-level ABS control system ensures optimum deceleration. Special brake cooling ducts at the front and rear guarantee braking stability also in racing. For the steering system, Audi Sporthas adopted the hydraulic rack-and-pinion unit from the GT3 model, albeit with an electrically operated pump. In spite of the cost benefits offered by the 5-hole cast aluminum wheels they have been specifically designed for racing purposes. Audi Sportalso offers a tire pressure warning system as an option.
In terms of passive safety, Audi Sportagain sets high standards. In addition to standard equipment such as a fire extinguishing system, safety nets for the driver and crash foam in the doors, Audi Sportexceeds the minimum requirements in many areas. The Audi Sport customer racing PS3 safety seat represents the most recent evolution of the PS1 model. It is standard equipment in the GT4 model as well as in the Audi customer racing models for GT3 and TCR racing. Like in the GT3 version of the R8 LMS the PS3 seat is mounted to the safety cage using the so-called 6-point fastening which results in additional safety. The safety nets are attached to the seats for optimum connection, and the 6-point harness corresponds to the GT3 standard. The axial and height adjustable steering wheel in combination with the seat are optimally suited for diverse body sizes. The team can fit the seat shell in various positions longitudinally, ensuring a safe and comfortable setup for each driving posture. A roof hatch facilitates rescue operations following an accident. To reduce the loads acting on the driver’s spinal column, the helmet can be removed upward and a Kendrick Extrication Device applied. Inside the car, the steel safety cage is mounted at six points to the Audi Space Frame (ASF) featuring an aluminum-CFRP mixed-material construction, plus there are two connections to engine bay braces. The FT3 safety fuel cell is filled using a dripless rapid-refueling system for racing.
In the ergonomically designed cockpit, the driver can activate and adjust various driving functions via the steering wheel and the center console. Like in the GT3 version of the R8 LMS the pedals by means of a pneumatic release system can be longitudinally adjusted in several steps. A central multi-function display within the driver’s view and a data logger create transparency with respect to operating conditions and data analysis.
The body components are largely identical to those of the production car but have been optimized to support the race car’s aerodynamics and thermal management of the cooling and braking systems. The production-based Audi Sport Performance Parts enhance the aerodynamics of the race car once more. The GT4 race car is closely oriented to the production model. Its chassis is produced at the same manufacturing facilities as the one of its road-approved sibling. Consequently, there are synergies for the Audi R8 LMS GT4 in terms of production and the Group-wide pool of components as well as service and maintenance – directly benefiting the customers.