frame structure and geometry to reduce weight, stiffen and lower the chassis. The car was built around a hand-welded oval tube frame, incorporating A-arm front suspension, rear live-axle with Watt's linkage, disc brakes, and Borrani wire wheels. The engine was the race-proven Tipo 168/62 Comp. V12 as used in the 250 Testa Rossa Le Mans winner. An all-alloy design utilizing a dry sump and six 38DCN Weber carburetors, it produced approximately at 7500 rpm and at 5500 rpm of torque. The gearbox was a new 5-speed unit with Porsche-type synchromesh. Bizzarrini focused his design effort on the car's aerodynamics in an attempt to improve top speed and stability. The body design was informed by wind tunnel testing at Pisa University as well as road and track testing with several prototypes. The resulting all-aluminium bodywork had a long, low nose, small radiator inlet, and distinctive air intakes on the nose with removable covers. Early testing resulted in the addition of a rear spoiler. The underside of the car was covered by a belly pan and had an additional spoiler underneath formed by the fuel tank cover. The aerodynamic design of the 250 GTO was a major technical innovation compared to previous Ferrari GT cars, and in line with contemporary developments by manufacturers such as Lotus. The bodies were constructed by Scaglietti, with the exception of early prototypes with bodies constructed in-house by Ferrari or by Pininfarina (in the case of s/n 2643 GT). Cars were produced in many colours, with the most famous being the bright red "Rosso Cina". The minimalist interior of a 250 GTO reflects the car's racing intentions. There is no speedometer, seats are cloth-upholstered, and neither carpeting nor a headliner was installed. Cockpit ventilation is via exterior air inlets. The exposed metal gate defining the shift pattern became a Ferrari tradition maintained in production models until replaced by steering column-mounted paddle shifters in the 2000s. Prototypes As the 250 GTO was heavily derived from the earlier 250 GT Berlinetta SWB, Ferrari engineers constructed two 250 GTO prototypes in 1961 by converting existing chassis of this type. The first prototype, designated in official photos as the 1961 Ferrari 250 GT Le Mans Berlinetta Sperimentale, was constructed from chassis 2643GT, originally a 1961 250 GT SWB. It was built to competition specification, which included a reinforced chassis, a competition gearbox and a Tipo 168/61 3.0 L engine tuned to