GM Motorama Firebirds

In the 1950s, General Motors considered the gas-turbine the engine of the distant future. To get the point across, it built a series of equally futuristic cars -- the GM Motorama Firebirds.

In contrast, Chrysler Corporation seemed to believe that turbine-engined cars were right around the corner in the mid-1950s. In April 1954, Chrysler engineer George Huebner stuffed a gas-turbine engine into an innocent-looking 1954 Plymouth. He then took the car from city to city and invited the press to drive it. Reporters loved it, giving Chrysler's turbine research program instant national notoriety.

By dropping gas turbine engines into otherwise everyday cars, Chrysler implied that this exotic form of power was just a step away from production. But General Motors, which actually had a running gas-turbine car before Chrysler did, took a longer-range view. GM developed turbine cars for its annual Motoramas. Called Firebird I, II, and III, they were obviously "cars of the future." As such, they said to Americans that turbine automobiles might be feasible someday, but not today.

That wasn't what people wanted to hear. Americans in the 1950s yearned for the future, and they wanted it now. Chrysler recognized that desire, played on it, and consequently got so much credit for developing automotive turbines that the public didn't give a hoot about GM's efforts. To most people, GM's turbine cars were just futuristic styling exercises; the power source was incidental.

This bothered Harley Earl, GM's legendary vice-president of styling, who dominated every Motorama from 1949 through the last one in 1961. Motoramas, as you may or may not recall, were hugely lavish displays that traveled around to major cities across the country in convoys of trucks and buses. When you entered the exhibit hall, there sat all the newest General Motors cars. At center stage was a continuous presentation of Broadway-style stage revues: pretty girls and good-looking guys singing and dancing their hearts out.

Classic Cars Image Gallery

GM Motorama Firebird on display at a 1954 Motorama
The Firebird gained its greatest fame as the
centerpiece of the 1954 Motorama touring shows. See more classic car pictures.

But the stars of these shows were always the dream cars. Every Motorama unveiled a new crop, so people kept coming back. (Then again, GM never charged admission.) Some Motoramas attracted as many as 2.3 million spectators nationwide.

Of course, the purpose of these shows was to bring home to the public the fact that the corporation had an eye on the future -- and that GM, more than any other automaker, was technically able to create just about any mechanical marvel you could imagine. But since each Motorama gave its audience an artful glimpse of things to come, Harley Earl had to keep looking further and further ahead and delivering more and more spectacular dream cars.

At first, when Chrysler started grabbing headlines with turbine-powered Plymouths, Earl wasn't too worried. He already had the Firebird I -- the first of the GM Motorama Firebirds -- nearly finished. But as time passed, the turbine wars tilted toward Chrysler and, do what he might. Earl couldn't catch up.

Learn more about Earl's valiant efforts and the first of the Firebirds on the next page.

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The GM Motorama Firebird's Beginnings

The first GM Motorama Firebird (the Roman numeral "I" is retrospective) appeared at the 1954 Motorama, staged in the grand ballroom at New York's Waldorf-Astoria Hotel. The car was basically a delta-winged jet fighter on four wheels.

GM Vice-President of Styling Harley Earl had seen photographs of a Douglas F4D Skyray and showed them to Robert F. (Bob) McLean. For the previous year's Motorama, McLean and Earl had designed the Corvette, which quickly entered production. And in working on that project, Earl and McLean had developed a strong student/mentor relationship.

Bob McLean was unusual in that he'd recently graduated from Cal Tech with dual degrees: one in mechanical engineering, one in industrial design. He'd owned and raced sports cars, and he understood aircraft, so he seemed a logical choice to head the design team for the first Firebird -- not that the project was all that difficult. McLean's job was basically to translate the Skyray into a fiberglass-bodied Motorama showstopper: a single seater, nominally a "sports car," with the driver shoved forward under a Plexiglas bubble and a turbine engine behind.

Most Motorama cars wore one of GM's five domestic nameplates. The 1953 Corvette, for example, was a Chevrolet. The 1951 XP-300 gave a glimpse at Buick's future. Firebird I, however, carried no marque name. Instead, it represented all of General Motors. That was appropriate, because it was a collaborative effort between GM Styling and General Motors Research Laboratories.

GM's Harley Earl and NASCAR's Bill France with a Firebird-topped NASCAR trophy
Earl and NASCAR founder Bill France, Sr., admire
the Harley Earl Trophy. Topped with a Firebird, it's
still presented to Daytona 500 race winners.

The man responsible for supplying turbine engines for the entire Firebird series was a young research engineer named William A. (Bill) Turunen who worked on experimental engines. He founded GM's turbine program in 1949 and continued to manage it throughout the Firebird era.

In a 1996 telephone interview, Turunen recalled that, "Harley Earl got interested in getting some cars for the Motorama shows. We'd been working on gas-turbine engines to see what their feasibility might be for truck and automotive use. Earl got together with our head of research, Charley McCuen, and the three of us met in Harley's office. He asked if we could make an engine for this car they were working on. The car was just an idea at the time. Earl had seen pictures of one of the jets and was intrigued with that shape."

"Not knowing any better, we said sure, we'd do it," Turunen continued. "So that was the start of the Firebird program. We made an engine for the first car...using one of the first vehicular turbines around. Then, in progression, Earl wanted another [car] for the next Motorama, so that became the Firebird II. Harley did what Harley wanted to do. He was a heckuva nice guy to work with, and I worked very closely with him. But he had very, very definite ideas."

Learn more about how Harley Earl's ideas became the first Firebird on the next page.

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The GM Motorama Firebird I's Speed Testing

Rover, the British automaker, had built a running turbine car before the GM Motorama Firebird I had been completed, and they had set some speed records with it in Europe. Charles L. McCuen, research engineer Bill Turunen's boss, initially planned to break the Rover's records by taking Firebird I to GM's track near Mesa, Arizona.

Wind tunnel tests showed that the car's aircraft shape -- plus the 400 shaft horsepower of its turbine engine -- would allow speeds over 200 mph, more than enough to outrun the Rover. Three-time Indianapolis 500 winner Mauri Rose, then on Chevrolet's payroll, would do the driving.

GM's Harley Earl and NASCAR driver Mauri Rose
GM's Harley Earl chats with test driver Mauri Rose,
a three-time Indy 500 winner, during shakedowns.

But before heading to Mesa, McCuen decided to do a little testing himself at the GM Proving Grounds near Milford, Michigan. According to one of designer Bob McLean's staff, design engineer Stefan Habsburg, "[McCuen] was completely fooled by the gas turbine's acceleration, which starts out deceptively slowly but then builds and builds and builds. On the far high-speed turn of the Milford oval, McCuen was going way too fast and lost it despite the track's high bank."

"The guard rail was designed for standard-height cars, but the Firebird I stood only 41 inches tall at the cockpit," Habsburg continued, "So when Charley lost control, the car went under the guard rail. It rolled and ended up in the grass on the other side. The body got totalled, and the only thing that saved McCuen's life was the headrest built into the contour seat."

Three additional factors conspired to make the Firebird I's performance unpredictable. First, the turbine gave no engine-braking effect, meaning that when McCuen lifted his foot off the accelerator, the car didn't slow appreciably. Second, because the car copied the look of a jet aircraft, its narrow 50- and 54-inch tread widths effectively raised the center of gravity, thus making the car more tippy than McCuen expected. Third, the suspension had been tuned not for cornering but for straight-line stability on smooth, straight roads.

The crash left McCuen badly injured. He spent months recovering, went back to work briefly, then took early retirement in 1956. His accident ended GM's plans for setting new turbine-car speed records.

Go to the next page to learn more about the Firebird I.

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GM Motorama Firebird I's Specifications

Fortunately -- after the unfortunate crash that badly injured driver Charley McCuen and wrecked the first Firebird -- the Firebird I's female plaster body molds were still intact down in GM Styling's fabrication shop. GM VP of Styling Harley Earl quickly ordered up a fresh set of fiberglass skins. These were finished just in time for the car to be shown at the 1954 Motorama.

The Firebird I's gas turbine engine was originally designed for heavy duty trucks, because GM Research was much more interested in adapting turbine power -- which in principle operates much like the turbojet engines in aircraft and stationary power plants -- to 18-wheelers than to passenger cars.

Designated GT-302, but also known as the "Whirlfire," this engine was physically huge, much larger and heavier than any contemporary piston V-8. It used a combination starter/generator and drove through what was basically a reprise of the Model T Ford's two-speed planetary gearbox. Shifts were controlled by hydraulic pressure, and there was no torque converter. A cone clutch engaged reverse, making it theoretically possible to put the car into reverse at speed to provide braking, just as it had been in Tin Lizzies.

As for chassis details, the front suspension employed conventional coil springs between upper and lower A-arms, but with ball joints instead of kingpins -- one of Ford's better ideas. The deDion rear suspension used longitudinal single-leaf springs. Brakes were 11-inch Alfin drums with dual master cylinders, one for the front wheels, one for the rears. In addition, braking flaps were built into the stubby "wings" to help slow the car from higher speeds. The flaps were split horizontally so the top halves flipped up at 90 degrees while the lowers flipped down.

The GM Motorama Firebird I's frame was a conventional ladder type, pointed at the front, with six cross-members and a kickup over the rear axle. The nose section housed a fiberglass fuel tank and had a single headlamp at the bottom. Dry, the Firebird I weighed 2,440 pounds, less than half as much as either of the two subsequent Firebirds. It also had roughly twice the horsepower.

Normal testing of this early iteration of GM's research turbine revealed two problems. First, the GT-302's fuel mileage was totally unacceptable: four to six mpg on average. Second, off-the-line acceleration didn't match that of most piston-driven cars. Once the turbine started revving, power eventually exceeded that of a typical 1954 V-8, but response was sluggish below 18,000 rpm.

That all changed when Earl called research engineer Bill Turunen back into his office in late 1954 to lay plans for a second turbine car, which would materialize as the 1956 Firebird II.

Continue to the next page for more details on the GM Motorama Firebird II.

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Plans for the GM Motorama Firebird II

By the time GM's Harley Earl turned his attention to the next Firebird project, design engineer Bill Turunen and his staff had come up with an improved gas turbine engine, the GT-304, for the GM Motorama Firebird II.

Unlike the 302, this engine utilized two rotating heat exchangers that recycled some of the combustion energy that had previously gone out the exhaust pipe. Recycling this heat made the GT-304 more fuel-efficient and responsive. Fuel availability was far less of a problem. Although the GM Firebirds relied on kerosene, a gas turbine engine will run on just about anything that burns.

Earl again turned to Bob McLean's studio to design and engineer the Firebird II. This time, though, Earl wanted to impress Motorama showgoers with the "Family Sedan of the Future." He realized that people had a hard time relating to the jet-like Firebird I, but had no problem accepting a stock Plymouth or Dodge with a gas-turbine engine.

Even so, Earl asked McLean to use titanium body skins, a Plexiglas greenhouse, aircraft-style instruments and steering wheel, and four thin-section individual seats. He also ordered the car to be set up with an electronic guidance system that would follow wires buried in automated roadways.

An early version of the 1956 GM Motorama Firebird II
The gas-turbine car concept evolved into the larger
Firebird II of 1956. Distinctive features of the
Firebird II included a titanium body and seating for
four under a Plexiglas dome.

Besides McLean, the Firebird II design staff included freshman stylist Norman J. James, who'd recently come from Pratt Institute; engineer Stefan Habsburg, also on his first major GM assignment; and veteran designers Byron Voight and Al Aldregetti. James and Habsburg did most of the creative work, and both agree that they didn't set any styling precedents. Yet Habsburg in particular points out that the car absolutely bristled with technical innovation.

The GM Motorama Firebird II's high-tech headlights.
When the GM Motorama Firebird II's
headlights were needed...

The GM Motorama Firebird II's high-tech headlights.
...they sprang from hiding places in the bodysides.

The use of titanium had to be the fabricators' most interesting challenge. There were actually two Firebird IIs built, one with a fiberglass body, the other with titanium skins. GM Styling had never worked with titanium before, but Earl wanted to try it, especially after Republic Steel made sheet stock available. Republic supplied Earl's fabrication people with 10-foot-by-4-foot sheets of 0.040-inch thickness, as well as 0.050-inch stock for the hood and decklid.

Titanium weighs half as much as steel, can't rust, and is extremely tough and unbending -- which makes it maddeningly hard to work with, as the parts fabrication crew immediately found out. When hammered, the surface picks up impurities that lead to cracking. The material is so armor-like, according to McLean, that edges couldn't be contoured, and cuts required special tools. A panel that would have taken 30 minutes to form in steel took 24 hours in titanium. Welds tended to discolor the metal, which Earl wanted to leave unpainted.

How did the Firebird II get out of the planning stage into fabrication? Find out on the next page.

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Creating the GM Motorama Firebird II

After many frustrating attempts to work with the titanium GM's VP of Styling Harley Earl wanted for the GM Motorama Firebird II's exterior, Bob McLean decided to abandon hand shaping and ordered Kirksite dies made for the major body sections.

He watched as the panels were stamped out of glowing titanium, which he said lit up bright yellow-gold at 920 degrees Fahrenheit. And at the 11th hour, to replace multiple welds, GM Research developed an epoxy resin to bond the titanium hull to the GM Motorama Firebird II's steel framing.

As a final effect. Earl asked that the titanium be burnished, much like the stainless-steel surface of the latter-day DeLorean car (McLean later worked for DeLorean, so he might have taken the idea with him). Because handprints smudged the titanium, the final surface got several coats of clear lacquer.

Earl Harley admires the GM Motorama Firebird II.
Harley Earl admires the titanium GM Motorama
Firebird II in Arizona.

A third technical tour de force was the Firebird II's air/oil suspension. Developed by GM's Deico Division, this system resembled Citroen's in that conventional springs were replaced by four interconnected hydropneumatic canisters, two up front and two at the rear.

An electric pump and accumulator forced oil into the canisters at pressures determined by sensors at each of the car's corners. Oil thus compressed the air, which set the vehicle's ride height and also acted as the suspension and shock-damping medium. Because the car was set up to run over smooth roads only, suspension travel was minimal. Also, ride height at speed was lower than at rest.

Two GM engineers drove the fiberglass Firebird II from Detroit to Atlanta and back for an SAE meeting and reported flawless performance; no mechanical problems of any sort. They did say, though, that the Plexiglas greenhouse made the interior pretty uncomfortable in hot weather, despite excellent air conditioning.

The titanium Firebird II (which was strictly a "pushmobile") not only had an aircraft-type instrument panel but an airplane-style cut-down steering wheel. During each Motorama performance, General Motors would show a brief, wide-screen movie in which the Firebird II came cruising down an automated roadway, the driver oblivious to traffic as he chatted with his family and they all enjoyed the passing scenery.

When the film ended, the screen lifted and the titanium-bodied car came rolling down a ramp toward the audience. At the foot of the ramp, the same family of four climbed out and started explaining the car's many wondrous features.

Once the Firebird II was complete, thoughts immediately turned to the future once again. See what would come next for GM's Motoramas on the next page.

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Designing the GM Motorama Firebird III

By far the most intriguing and influential of the GM Motorama gas turbine engine cars was the Firebird III, which arrived in late 1958. It turned out to be the only member of this trio to have any appreciable impact on GM production cars.

Dave Holls, then head of the Cadillac studio, said that Firebird III was important because it broke the old corporate rules of surface development. No longer did stylists have to include VP of Styling Harley Earl's traditional highlight lines in their designs.

This new direction appeared on all 1959 General Motors production cars; you notice it especially in the rounded, more tubular surfaces of that year's Cadillac. As for a direct design influence, the 1961 Cadillac picked up the Firebird's rear "skegs" -- those stubby little fins that hung down off the bottoms of the rear fenders. In addition, the Firebird III had very little chrome and almost no parallel lines. And finally, after putting the ultimate twist on tailfins, GM began to tone down the fin treatments on production cars.

Of course, most of these changes happened after Earl retired in late 1958.

The two men most responsible for the Firebird Ill's development were again Norm James and Stefan Habsburg. Because he'd decided to pursue a management career, Bob McLean handed the assignment to these two. "[McLean] gave the analogy of ordering dinner at a restaurant," James said in a telephone interview. "He wouldn't go in the kitchen and cook the meal himself, but if he didn't like what we'd served him, he'd send it back."

GM Motorama Firebird III designer Norm James exits a mock-up of the vehicle.
Development of a third-generation Firebird began in
1957. Stylist Norm James climbs out of a design
buck in December of that year.

"The way our studio was set up," James continued, "was a carryover from the Firebird II. Stefan and I would work together to develop the car and would be responsible for it. Stefan handled all the technical and mechanical elements, and I had charge of the car's styling and aesthetics."

Early in the program, Harley Earl told McLean that he wanted the Firebird III to be an extension of the theme laid down by Pontiac's 1956 Motorama dream car, the Club de Mer. "Build on the Club de Mer," suggested Earl. And so, in the beginning, James and Habsburg built on the Club de Mer theme.

Norm James again: "But then one day Mr. Earl came in and described the show atmosphere he wanted to create. He said, 'I want people to stand in line four across around the city block, just waiting to get in. In the grand ballroom, people will be crowded around the car so deep that they'll have to stay for an extra show to get a clear view of it.' And he wanted the car itself to look like 'what you'd expect the astronauts to drive to their rocket launchpad on their way to the moon.' Speaking in generalities about the car's appearance, Mr. Earl said, 'You know, when you go to a Las Vegas show, you don't expect to see your wife up there onstage. You expect to see a real floozy. I want this car to be a real floozy!'"

The fin-laden GM Motorama Firebird III as seen from the rear.
To stylist Norm James, a floozy meant fins, and from
the rear, the Firebird III showed off plenty of them.

James interpreted the floozy reference to mean that Earl wanted tailfins: big, tall ones and lots of them. He even made a sketch of the Waldorf ballroom as Earl envisioned it: a sea of heads with a series of tall fins, an open hood and gullwing doors thrusting out. This, he felt, was what Earl sought in his quest for ever more-striking concept cars.

How to make this idea a reality? Get details on the next page.

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GM Motorama Firebird III Prototypes

From GM Motorama Firebird III designer Norm James's sketch of the envisioned Motorama crowd came a new series of styling studies, starting around March 1957. These were initially inspired, as James put it, " a Nike two-stage missile I'd seen at an air show. The missile had four dominant second-stage fins midway along its length, set at 45 degrees to the launch rail. The Club de Mer's twin windscreens then evolved into a set of fully separated blisters, and the front end tapered down to a nose inlet patterned after the North American Aviation F-100 fighter."

On his own initiative, James made a full-sized string drawing of this missile/fighter car. It had four fins, keyed to the location of the rear wheels. But James felt the rear didn't look right, due to the long, barren, extended overhang. "Stefan [Habsburg] and I were concerned with this big plank-looking afterbody" he reflected, "so at one point Stefan walked up to the board and said, 'What if we try something like this?' Whereupon he proceeded to add a large dorsal fin and the two trailing lower skegs."

"My first thought was, 'hey, you can't do that! You can't integrate a three-fin set with a four-fin set';" recalled James. "But I could also see immediately that Stefan had created the mass balance that the design was missing. I went up and re-proportioned the tail elements; then we both stepped back to see what we'd created. It looked good, so I developed full-sized string drawings for the corresponding front, rear and half-plan views."

Note: String drawings use yarn stretched between pushpins, a technique invented by James.

"Once it was all done, we called in Bob McLean to take a look," said James. "He seemed pleased and told us to keep going with the Club de Mer version but to also build a second mockup of the new design."

Harley Earl with the assorted prototypes produced while developing the GM Motorama Firebird III.
Like a proud parent, GM VP of Styling Harley Earl
poses with the whole family of gas turbine-powered
concept cars he had conjured up when the
Firebird III was being tested at General Motors's
Mesa, Arizona, proving grounds in 1958.

When both mockups were ready, McLean invited VP of Styling Harley Earl to visit the studio. James isn't certain whether Earl had seen the missile/fighter mockup previously, but there's a good chance he had, because Earl often roamed the studios after everyone else had left for the night.

In this instance, though, Earl unlocked the studio door and walked in. McLean was standing beside the Club de Mer mockup; James and Habsburg stood by their newer theme model, hearts pumping. Earl glanced at the Club de Mer mockup, then immediately caught a glimpse of the missile/fighter model, leaned forward, did a smooth right turn and made a half circle around the new theme car. It didn't take long for him to make up his mind. He liked it. This, he smiled, would be the Firebird III.

After this endorsement, the designers set to the task of creating the Firebird III. Learn more on the next page.

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Creating the GM Motorama Firebird III

After viewing the space-aged concept car designers Norm James and Stefan Habsburg had created to be the GM Motorama Firebird III, GM VP of Styling Harley Earl was very pleased, but he did make a few recommendations.

Among them, he suggested the car's nose be extended about five inches in plan view. James brought it out to a prow and added a windsplit up the center of the hood, running rearward between the twin cockpits.

In August 1957, Earl left for his annual tour of European motor shows. During his absence, the GM styling committee, led by Earl's second in command, Bill Mitchell, came into the studio. These men weren't nearly so pleased as Earl with what they saw, and they ordered three of the Firebird III's fins removed. Reluctantly, James and Habsburg took them off.

When Earl returned, he viewed the full-size clay model in the styling auditorium and, of course, noticed the missing fins. "After a pause," recalled James, "Mr. Earl began, 'You know, when I came into the studio that day for the first time and saw the mockup, I could actually see the finished car at the Waldorf, and it was exactly as I'd pictured it.' Another pause, and then he continued, 'Now why don't you take the car back and make it the way it was when I left?' With that, he turned and walked out. Stefan and I were way in the back of the auditorium, and, wow, were we ecstatic! If there'd been 'high-fives' back then, we'd be doing them."

The Firebird III used an improved version of GM's experimental gas turbine engine, the GT-305, which was finally as fuel-efficient as a small piston V-8 of the period: 16 to 20 mpg. The GT-305 also offered less weight and bulk than the GT-304.

The GM Motorama Firebird III featured gull-wing doors and an abundance of fins.
The twin-canopy cockpit on the Firebird III was
inspired by the 1956 Pontiac Club de Mer Motorama
special. It featured a flip-up door and dome
combination, plus seven fins. With all its various
hatches and covers open, the Firebird III looked
like a Swiss Army knife.

Beneath the GM Motorama Firebird III's wild body was an unusual "tuning-fork" frame. This employed a deep longitudinal rail that ran between the two cockpits, aft of which it attached to a U-shaped section that cradled the powertrain, including another modified four-speed Hydra-Matic. Up front, welded to the main rail, was a T-shaped subsection that supported the front suspension plus a small, four-cylinder piston engine that provided power for the Firebird Ill's many subsystems.

Continue to the next page to learn more about the Firebird III.

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The GM Motorama Firebird III

A series of exotic subsystems totally filled the innards of the GM Motorama Firebird III. The most interesting was Unicontrol, a joystick that allowed the driver to go, stop, and steer with a single lever. Push it forward to accelerate, pull it back to brake, move it side to side to turn.

For reverse, you rotated the lever 20 degrees left or right; Park was selected by an 80-degree twist. All these actions were accomplished by servos controlled by three primitive analog computers, which not only gave the joystick some "feel" but also centered the steering.

The GM Motorama Firebird III
The snazzy -- and influential --
GM Motorama Firebird III.

The computers monitored vehicle speed and front-tire turn angle to ensure that the driver didn't "outsteer" the car. In other words, if the driver suddenly shoved the stick too hard to one side, cranking in too much steering lock, the computer scaled back and balanced steering, braking, and acceleration inputs so the car wouldn't careen out of control or turn over.

There was also a large onboard electronics package that took up most of the space between the Firebird III's U-shaped engine cradle and the left rear body. The fuel tank and twin 12-volt batteries balanced this on the right side.

The GM Motorama Firebird Ill's 12-bhp APU (for Auxiliary Power Unit, a small piston engine) drove the 1,000-psi steering and braking pumps, activated the airbraking flaps as on the Firebird II, powered both a 110-volt alternating-current generator (so that the car didn't need to be plugged into house current for outdoor demonstrations) and another generator for the 12-volt batteries, drove the air-conditioning compressor, and supplied up to 3,000 psi for the air/oil suspension system.

The interconnected suspension canisters automatically adjusted ride height, which depended on car speed and gave a variable-rate spring effect by its valving.

Firebird Ill's front suspension was unusual for the late 1950s in that it used a good old-fashioned beam axle. But unlike 1930s installations, this axle was located by four control arms anchored to the front subframe. Not only did this arrangement make for a lower front silhouette but, in combination with the deDion rear, it offered a roll center only 19 inches off the ground.

The GM Motorama Firebird III's brakes were also unusual. By the late 1950s, GM Research realized that the days of drum brakes were coming to an end, and discs would soon take over. Yet for the Firebird III, GM designed and built the ultimate set of automotive drum brakes: 11x4-inch drums cast into each of the car's alloy wheels. The drums were faced with iron, and the shoes used sintered metallic linings. Special cast-in cooling passages between the drum and wheel surfaces took in air at the hub and spun it out through slots in the perimeter.

The GM Motorama Firebird III preparing to perform on GM's Mesa, Arizona, proving grounds.
The Firebird III prepares to perform at GM's Mesa,
Arizona, proving grounds. An improved GT-305 gas
turbine engine was housed in the rear of the car.
A small four-cylinder piston engine in front
powered various subsystems.

Also unusual was the Firebird Ill's use of antilock brakes and a so-called "grade retarder." The latter comprised a series of friction discs acting on the rear axle shafts. The discs ran in oil and were brought to bear during deceleration with fluid pressure from the automatic transmission. Both the grade retarder and the airbrake flaps kicked in during stops from over 30 mph.

After getting the Firebird III up and running. General Motors commissioned a movie that documented the car's styling and engineering development, and highlighted its many features. Much of the footage was shot at GM's Mesa Proving Grounds, where the car performed beautifully. Parts of the movie were shown at the 1959 Motoramas.

What did the future hold for GM and its series of Firebirds? Continue to the next page to find out.

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The GM Motorama Firebirds' Legacy

After the success of the initial three GM Motorama Firebirds, engineer Bob McLean's research studio briefly entertained plans to design and build a fourth Firebird.

An overhead drawing showing the concept for a GM Motorama Firebird IV.
Plans for a Firebird IV sprang from this
radical overhead-view sketch.

This would have been a large three-passenger "ground-effects" machine, part of a wide-ranging study into automated roadways. It got as far as a full-sized wooden space frame and seating buck, but at that point Design Staff apparently lost interest in the ground-effects vehicle.

Design buck for the never-completed GM Motorama Firebird IV.
Work on the three-seat "ground-effects" car
got as far as this April 1960 frame model

Maybe GM's designers and engineers realized that turbine-powered passenger cars weren't even the stuff of dreams, much less of reality -- something Chrysler hadn't quite admitted yet.

The chart below provides a comparative look at the stuff of GM/Chrysler's dreams: the GM Motorama Firebird I, II, and III.

Firebird Comparisons

Firebird I
Firebird II
Firebird III
GM code designation
XP-21 XP-43
Gas turbine designation
GT-302 GT-304
Gas turbine type
Simple cycle
Maximum horsepower
400 (rpm NA)
200@28,000 225@24,000
Transmission 2-speed planetary
4-speed automatic
4-speed automatic
Fuel consumption
4-6 mpg
8-10 mpg
16-20 mpg
Wheelbase, inches
100 120 119
Overall length, inches
223 235 248
Overall height, inches
41 (55 at fin)
52.8 44.8 (57 at fin)
Overall width, inches
80 70.6
Front tread, inches
50 60
Rear tread, inches
54 57
Curb weight, pounds
2,440 5,300
Tire size
6.70x16 8.20x16
Front suspension
Independent Independent
Solid axle
Rear suspension
Ind., deDion
Ind., swing axles
Ind., deDion
Body material
Fiberglass Titanium/fiberglass Fiberglass

The Firebird program's great legacy, of course, was to lend its name to Pontiac's ponycars, starting in 1967. In that sense, it's still alive today, as are the gas turbine engine cars themselves.

Firebird III recently was taken out of mothballs and put back in running order. The fiberglass-bodied Firebird II is also fully operational (it ran alongside Chrysler's famed 1963 Turbine Car at the Straits Area Antique Auto Show in St. Ignace, Michigan), while its titanium-skinned sister is safely tucked away in a warehouse. As for Firebird I, General Motors recently reacquired it from the Henry Ford Museum and plans to restore it, too.

GM also tells us that all three Firebirds might even take to the road again, just as in Motorama days. If they ever come to your town, don't miss them.

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