El TVR Cerbera Speed 12, originalmente conocido como el proyecto 7/12, era un vehículo conceptual de alto rendimiento, diseñado por TVR en 1997. Basado en parte en el entonces actual hardware de TVR, el vehículo fue pensado para ser el automóvil de calle con el rendimiento más alto del mundo. Sin embargo, debido a problemas durante su desarrollo, los cambios en las regulaciones de la clase GT1 y la eventual decisión de que el vehículo era simplemente incapaz de ser utilizado como un coche de calle, le dio fin a la idea, forzando a los ejecutivos de TVR a abandonar el proyecto.1
El motor del Cerbera Speed, con 7.7 litros y doce cilindros, era supuestamente capaz de producir casi mil caballos de fuerza, aunque nunca fue hecha una medida exacta. No obstante, se dijo que su funcionamiento era asombroso, y era capaz de alcanzar 60 millas por hora (94 km/h) en menos de 3 segundos, y tener una velocidad máxima cercana a la del McLaren F1. Lleva montado un motor V12 capaz de generar 811cv de potencia.
The vehicle, known as the TVR Project 7/12, first appeared at the 1996 Birmingham Motor Show and dominated the show once it was unveiled, attracting more crowds than any other cars in the show. The number "7" referred to the 7.7 litre (actually 7.73 L) engine, and "12" for the number of cylinders in the engine. TVR claimed that the engine would have a power output of more than 800 hp (597 kW) and be faster than the McLaren F1. The first concepts shown were based on FIA GT1 class race rules which meant that they would be restricted to 660 hp (492 kW) but the weight would be kept at roughly 1,000 kg (2,205 lb). The road car would weigh the same but without the restrictors, the power was greatly increased. Despite the claims, the actual output figure was not recorded. It had a specially built 6-speed manual transmission and clutch. The engine was essentially made from two TVR AJP6 straight-6 engines mated on a single crankshaft. Unusually for an automobile of its type, the Speed Twelve's engine block was not constructed of cast iron or aluminium alloy, but rather of steel and was designed by John Ravenscroft.
