Acura Motorsports Reveals LMDh Prototype
Acura Motorsports has released the first official images and details for the all-new, electrified Acura ARX-06 prototype sports car, which will make its competition debut next January at the Rolex 24 at Daytona, the company announced.
The ARX-06 features Acura-specific bodywork and aerodynamics based around an all-new ORECA LMDh chassis, which utilizes an electrified hybrid power unit featuring a new twin-turbocharged 2.4 liter V6 internal combustion engine designed, developed and manufactured by Honda Performance Development [HPD] the racing arm for Acura Motorsports in North America.
“Precision Crafted Performance is at the heart of everything Acura does,” said Jon Ikeda, vice president and Acura brand officer. “If you’re a performance brand, you have to go racing. It’s that simple. Both the existing ARX-05 prototype and our production-based NSX GT3 have proven to be race- and championship-winning designs on tracks all across North America. Now, with the introduction of the new, electrified Acura ARX-06, we look forward to facing off against other premium automotive brands from around the world – and continuing our winning ways.”
The Acura AR24e power unit was developed by Honda Performance Development to bring electrification to Acura’s endurance sports car racing program. The complete hybrid power unit is based around the Acura AR24e internal combustion engine (ICE), an all-new bespoke 2.4-lliter, twin-turbocharged direct injection racing V6 that was designed, developed and manufactured by HPD.
At 2.4 liters, this is the smallest displacement ICE conceived by HPD for endurance racing, yet still meets the performance target of 500 kW as measured at the rear axle by torque meters, engineers said. It features a 90-degree V-angle to reduce its center of gravity and polar moment of inertia. In addition, the combustion chamber has been designed to run on sustainable low-carbon fuel.
The hybrid power plant includes an IMSA-specified electric Bosch Motor Generator Unit (MGU) and Williams Advanced Engineering battery pack. The MGU is contained in a common transmission casing and gearbox internals provided by Xtrac. The battery, within the chassis survival cell, is built by Williams Advanced Engineering. The HPD Electrical Group completed both hardware and software development to best match the spec MGU and battery pack to the Acura ICE.
Both IMSA in North America and FIA World Endurance Championship rules require manufacturers to use one of four approved prototype chassis, fitted with IMSA-homologated, manufacturer-designed and branded bodywork and engines.
HPD and Acura have elected to continue their relationship with ORECA [ORganisation Exploitation Compétition Automobiles]. Since moving into chassis design and construction in 2007, ORECA has produced a series of winning sports prototypes, including the Acura ARX-05.
HPD’s Vehicle Performance Group worked closely with the ORECA design team and engineers to simulate chassis layout geometries and lap time optimization studies. They also “coded” the new car into HPD’s static and dynamic Driver in the Loop simulators to begin development of the car’s vehicle dynamics and vehicle dynamic control systems, the company said.
Critical to the projects was a clean sheet hybrid powertrain control system, brake-by-wire and vehicle dynamics control system – all written in-house at HPD. This control system architecture was implemented on a Formula 1-spec ECU hardware platform. HPD also utilizes its custom, in-house developed ultra-high speed data logging system.
Exterior styling of the Acura ARX-06 was led by the Acura Design Studio in Los Angeles, California, in conjunction with HPD and ORECA, Acura said.
HPD’s aerodynamics engineers and in-house CFD aero engineers worked with the Acura styling studio and chassis builder ORECA to help develop the styling and maximize the aerodynamic performance envelope of the ARX-06, while keeping it within the homologation boxes as specified by IMSA and the FIA.
Driver and team input was also sought throughout the design process, Acura said. One effective change was a revision to the placement of the rearview mirrors – a seemingly minor adjustment that in fact has a large effect on vehicle aerodynamics. Using VR headsets, the drivers were able to sit in the car virtually and recommend a much lower placement for the side mirrors, improving both the aero efficiency of the ARX-06 and visibility for the drivers.
Acura will continue its partnerships with the Wayne Taylor Racing and Meyer Shank Racing organizations to campaign a pair of hybrid-powered Acura ARX-06 entries in the featured GTP category of the 2023 IMSA WeatherTech SportsCar Championship.
