Designed by new engineer Stefan Fober, the car was an updated version of the ARC1, with reworked aerodynamics by McLaren designer Bob Bell, and the improved Cosworth DFR engine being worked into the chassis.
Deseñado por novo enxeñeiro Stefan Fober, o coche era unha versión actualizada do ARC1, cunha aerodinámica reelaborada polo deseñador de McLaren Bob Bell, e a mellora do motor Cosworth DFR comezaron a traballar no chasis.