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1954 GMC XP-21 Firebird I

With Key features reminiscent of the Douglas Skyray delta wing fighter jet, the Firebird 1 originally taxied into the 1954 General Motors Motorama as the 1954 XP-21 Firebird concept. Highlighted by a jet-like nose, cockpit-like passenger cabin, and open front wheels, plus a miniature wing and vertical tail fin, the jet theme of the single-passenger experimental car continues under the hood as well. Powered by a 370-horsepower Whirlfire GT-302 Turbo-power gas turbine engine, the single-passenger Firebird 1 concept was never intended to be put into production but instead was built strictly for the proving ground and test track.

by GM


In the early 1930s, General Motors had done a reasonable amount of research on the feasibility of gas turbine engines in vehicles, but it wasn't until the early 1950s that they actually began building an actual engine. Emmett Conklin led the project.

A series of three concept vehicles that were designed by Harley Earl, the GM Firebird was built by General Motors for the 1953, 1956 and 1959 Motorama auto shows. These vehicles were inspired deeply by innovations in fighter aircraft design at the time. These designs were never intended for production, but instead to showcase the extremes in both technology and design that GM was able to achieve. Still making regular car show appearances today, these concepts were very recently placed on display at the Henry Ford Museum in Dearborn, Michigan.

The Firebird XP-21 was created in 1953 by the research team and was eventually referred to as the Firebird I, basically a jet airplane on wheels. The first gas turbine powered vehicle tested in the U.S. the design was incredibly impractical, and featured a bubble topped canopy over a single seat cockpit. This first concept also had a bullet shaped fuselage that was made completely of fiberglass, short wings and a vertical tail fin. The entire vehicle weighed 2,500 lbs and had a 370 hp Whirllfire Turbo Power gas turbine engine which had two speeds, and expelled jet exhaust at around 1,250 °F.

Conklin was originally the only person that was qualified to drive the concept, and he tested it up to 100 mph. Unfortunately, when he shifted into second gear, the tires lost their traction under the extreme engine torque and he immediately slowed down the vehicle due to fear or an imminent crash. Later, race car driver Maury Rose tested the vehicle at the Indianapolis Speedway. This concept vehicle was never intended to test the speed potential or power of the gas turbine, but basically the ‘practical feasibility' of its use. The braking system features drums on the outside of the wheels to facilitate fast cooling unlike the standard drum systems, and the wings had aircraft style flaps for slowing from high speed.

The second of the three gas-turbine powered experimental Firebirds that were developed by GM during the 1950's, the Firebird II was in an attempt for alternative means of automobile propulsion. It was publicly unveiled at the GM Motorama of 1956 at the NY city's Waldorf-Astoria Hotel. It was a revolutionary form of family transportation that was destined for travel along the 'Safety Autoway' of the future. The Firebird II was a much more practical design, and was a four-seat family vehicle. Featuring a low and wide design, the II featured large dual air intakes in the front, a vertical tail fin and a high bubble canopy top.

Harley's vision for the Firebird II was that of a four-seat family vehicle that was comfortable and enjoyable to drive. He created two identical bodies for the Firebird III, one made of titanium and one of fiberglass.

The entire exterior of the one vehicle was constructed of titanium at it was the first time this lightweight metal was used in the construction of a motorcar. At Earl's insistence, the titanium body was left unpainted and was brush-finished to a satin luster. With an engine output of 200 hp, the team figured out a way to solve the exhaust heat problem, feeding it through a regenerative system which allowed the whole engine to operate at nearly 1,000 °F cooler, and also to power the accessories. This vehicle the first to utilize four wheel disc brakes, with a fully independent suspension along with a sophisticated guidance system, intended to be used with the 'the highway of the future', as an electrical wire would be embedded into a roadway that would send signals that could aid future vehicles and avoid accidents.

Aerodynamic, the Firebird II featured a low tapered nose to the dorsal fin deck and duel tanks suspended from the rear fender on either side of the car. When a magnetic key was inserted into a slot on the body panel, sections under the transparent canopy automatically lifted up from the doors. The Firebird II featured a luggage compartment that could hold up to eight pieces of specially styled lightweight fitted luggage. The compartment that was just placed below the rear deck also rose to waist height easily with just the flip of a switch. The inside of the Firebird II came with four individually adjustable, reclining lounge seats that provided maximum passenger comfort and also snack tables for use during automated travel.

Constructed in 1958, the Firebird III was finally unveiled at Motorama in 1959. Much like its counterparts, this third model was yet another overly extravagant prototype with a titanium exterior and seven short wings and tail fins that were extensively tested in a wind tunnel. The III was a two-seater powered by a 225 hp Whirlfire GT-305 gas turbine engine and a two cylinder 10 hp gas engine to power all of its accessories. The outside featured a double bubble canopy and various technical advances that made it much more practical. These advancements included cruise control, air-conditioning and anti-lock brakes.

Other revolutionary advances in the design included special air drag brakes, very similar to those found on aircrafts, these emerged from flat panels in the bodywork of the vehicle to slow it down from high speeds. An automated guidance system was also placed in the vehicle, to avoid accidents and 'no hold' steering, which was controlled by a joystick that was positioned between the two seats. The Firebird III featured a much more futuristic design and driving it was much like flying a plane.

by Jessican Donaldson