19. October 2023

RONAL GROUP announces details of racing wheel for Lamborghini SC63

Härkingen/Switzerland, 2023/10/19 – At the end of July, RONAL GROUP announced its technical partnership with Lamborghini Squadra Corse and the development of the motorsport wheel for the Lamborghini SC63 race car. This will participate in the FIA World Endurance Championship and the series of the US automotive sports organization IMSA (International Motor Sport Association) from 2024. Now there are more details about the monoblock wheels for the LMDh prototype.

When constructing such wheels, the most important aspects are structure, function, weight, aerodynamics, bending/stiffness and safety – they must be adapted to the special stresses of motorsport and additionally fulfill a customer-specific design.

Aero ring and characteristic Lamborghini design elements

The wheel is one-piece aluminum forging which includes an aero ring, thereby combining technology and aesthetics for aerodynamic efficiency. The distinctive aero ring has small circumferential holes which allow water, dust and dirt to pass through together with the hot air generated by the brakes – so it even provides a brake cooling and thermal management function  which improves the aerodynamic efficiency in the area around the wheel and also downstream. “It was a significant design and production feasibility challenge to obtain a very lightweight and functional aero ring fully integrated within a single piece monoblock wheel – regulations require that the wheel must be a single piece of metal. This was achievable only thanks to the use of 5 axis milling machines and the expertise of the development team”, says Matteo Melara, Head of R&D at App-Tech and responsible for the design.

The basic color of the wheels is matt black. The front wheel has the dimensions 12.5″x18″ and weight of 8.75 kg, the rear wheel 14″x18″ and 9.25 kg. The weight is the minimum permitted by the technical regulations. All wheels are equipped with a center lock surrounded by a colored annulus. Its main function is to visually help the mechanics identify where the center lock is located, so they can access it immediately at pit stops.

The hexagon and the “Y” are stylistic elements that have characterized the Lamborghini design since the very beginning and are at the same time both sporty and elegant. “The RONAL GROUP engineers have picked up this iconic style to create a tailor-made design to fit the customer’s wishes. Behind the iconic Lamborghini design theme, we built an optimized structure to sustain performance at all the full load cases whilst achieving an optimum weight. The end product combines high-level performance, structure and style”, explains Melara.

Combination of state-of-the-art machining, technologies and long-lasting know-how

A range of different specific technologies and machines are required to construct such a high-performance racing wheel. A forged blank is flow-formed and is then passed to machining/turning, first on a 3 axis machine and then on a 5 axis milling machine (special milling). This top-notch 5 axis milling technology is utilized to reach unique structural performance using an aluminum forging. Compared to the result of a standard casting process, the 5 axis technology allows the best “double t” shape of the spoke to be obtained, so as to minimize weight and increase stiffness and load capability. The same is true of the aero ring: Excess materials which are not required are removed by the 5 axis machine so as to obtain the optimum weight. Melara: “The combination of these technologies – high mechanical characteristics and homogeneous material due to forging plus the geometrical optimization thanks to milling – allows us to obtain the unique structural performance.”

The product can also be equipped with anti-skid features to prevent rotation between tire and wheel that could be generated by rotational forces or by acceleration with the engine of a powerful car or by braking. The profile of the wheel is therefore different from that of standard wheels, as it must withstand the maximum stresses of the demanding race tracks e.g. when encountering bumps, corners or braking.

As a final step the RONAL logo as well as the mentioned green and red “Y” and the colored annulus surrounding the center lock are applied via Pad Printing, an indirect pressure process involving the application of an elastic pad with different geometries to the surface of a wheel.