On This Day

Thursday 21st January 1954

66 years ago

General Motors revealed the first concept turbine-powered vehicle, the Firebird XP-21, designed by Harley Earl, which was essentially a jet airplane on wheels. It was named in imitation of the US military's experimental jet-powered aircraft, which had code numbers like XP-59A. The design was entirely impractical, with a bubble topped canopy over a single seat cockpit, a bullet shaped fuselage made entirely of fiberglass, short wings, and a vertical tail fin. It has a 370 hp (280 kW) Whirlfire Turbo Power gas turbine engine, which had two speeds, and expeled jet exhaust at 1,250 °F (677 °C). The entire weight of the car was 2,500 lb (1,134 kg) and had a 100 inch wheelbase. Engineers tested it up to 100 mph (160 km/h), but upon shifting into second gear the tyres lost traction under the extreme engine torque and they immediately slowed down for fear of crashing. The car was later test driven at the Indianapolis Speedway by race car driver Mauri Rose. The car was never actually intended to test the power or speed potential of the gas turbine, but merely the practical feasibility of its use. The braking system differs from standard drum systems, in that the drums are on the outside of the wheels to facilitate fast cooling, and the wings actually have aircraft style flaps for slowing from high speed. A miniature version of the FirebirdI crowns the Harley J. Earl Trophy, given to the winner of the Daytona 500.