Grand Prix Masters was a one-make motor racing series featuring retired Formula One drivers. The inaugural (and sole 2005) event, at the Kyalami Grand Prix Circuit in South Africa, took place on 11–13 November, but the series folded after a two-race season in 2006. Concept Grand Prix Masters was modeled on the lucrative seniors tours of golf and tennis. In order to compete, drivers must: Have retired from all forms of open wheel racing Have competed in (and retired from) F1 for two complete seasons Have passed a medical examination Be more than 45 years (later 40 in 2006) on 1 January for the season to follow Car All participants raced identical open wheel cars, which are based on the 2000 Reynard 2KI Champ Car. The chassis was built by English constructor Delta Motorsport, and was powered by a naturally aspirated, 3.5-litre, 80-degree V8 engine produced by Nicholson McLaren. The engine was based on the Cosworth XB engines previously used in IndyCar racing, and according to the series' organisers, it produced more than 650bhp at 10,400 rpm with over torque at 7,800 rpm. In 2007 cars were to have been powered by a Mecachrome 90-degree V8 4.0 litre. It developed and revved to in excess of 9500 rpm. Gearbox operation was controlled by a contemporary paddle shift arrangement. Grand Prix Masters promoters boasted that the 650 kg (1433 lb.) cars reach . Claiming that the combination of stable aerodynamics and considerably simpler technology (than in use in modern Formula One) better demonstrate driver skill and promoted overtaking, electronic "drivers' aids" (such as traction control, power steering and ABS) were absent, and brakes were made of steel rather than carbon (as in many contemporary single seater race cars) to increase braking distances. On track The Grand Prix Masters car first ran in late-September 2005 in the hands of Delta Motorsport Operations Director Simon Dowson. He reported a successful shakedown, despite appearing to sit very high in the car, his helmet appearing to sit level with the top of the roll-over hoop. In mid-October 2005, Nigel Mansell and René Arnoux tested the car at the Pembrey Circuit in South Wales. 26 October saw the first multi-car test for the series, with Mansell, Andrea de Cesaris, Stefan Johansson, Derek Warwick, Alex Caffi, Hans-Joachim Stuck, Patrick Tambay and Christian Danner running at the Silverstone Circuit in England. De Cesaris was fastest, Danner slowest whilst