Technology and design took a dramatic leaf forward during the mid-1970s in the Japanese market, but it would remain a concept after failing to find approval by regulatory bodies for sale in Japan or overseas. It was exotic, wedge-shaped, and powered by a 2.8-liter Nissan L28E SOHC straight-six engine sourced from the Datsun 280Z and 280ZX. The rear mid-engine supercar had a curb weight of just over 2,000 lbs (920 kg) with a power-to-weight ratio that rivaled contemporary Porsche models.
Minoru Hayashi's desire to compete in the 24 Hours of Le Mans led to the creation of the Dome concept cars. His journey began with a re-bodied Honda S600 coupe that he built into a race car during the mid-1960s. Its shape earned it the nickname, the 'Karasu', meaning 'crown' in Japanese. The car won its debut race at the Suzuka Clubman Race, inspiring another creation for 1966, the 'Macransa', a more extensively modified Honda S800. Next came the 'Kusabi' three years later, and the 'Panic' in 1971.
In 1975, Hayashi formed Dome Co. Ltd (translates to 'child's dream' in Japanese) for the development of road-going and racing machines. The company's first concept arrived in 1978, and by the 1980s, they had become a sportscar constructor designing and building the Group C spec Toyota TOM'S cars to compete in the All Japan Super Silhouette Championship. Later, they contested the All Japan Sports Prototype Championship, World Sportscar Championship, and even Formula Three. Near the close of the 1980s, Dome returned to production car design, establishing a design studio called Jiotto Design to design cars with its own quarter-scale wind tunnel. The studio produced a supercar called the Jiotto Caspita, but it never entered production due to the recession.
In the mid-1990s, the company announced its plan to enter F1 with a car designed by Akiyoshi Uko called the Dome F105. This was followed by the Dome F106, and neither car saw action. By 1999, all development work halted.
The first Dome concept car designed for road use was the Nissan L28-powered Dome Zero. It was intended to be the world's lowest-riding sports car, with a height of 980mm. The car had a 156.7-inch length, a width of 69.7 inches, and a height of 38.6 inches. It had an independent double-wishbone suspension, and four-wheel disc brakes with the rears being mounted inboard. The front brake calipers were sourced from a Subaru Leone and the steering column was sourced from a Honda Accord. The interior door pulls were from a Toyota Celica.
Mounted mid-ship was a 2.8-liter (2753cc) Nissan L28E SOHC straight-six engine offering 143 horsepower and 166 lbs.-ft of torque. It was paired with a ZF five-speed transmission.
The wedge-shaped exterior was inspired by the many similarly shaped supercars and prototypes from Europe, including the Lamborghini Countach, the Lancia Stratos Zero, and the Ferrari Berlinetta Boxer.
The Dome Zero prototype made its debut in 1978 at the 48th Geneva Motor Show and although it found interest from the public, it was unable to achieve Japanese road certification. Failing to achieve Japanese homologation, a second prototype road car was built, dubbed the Zero P2. This second attempt at building a road-going car was intended for export and sale in countries such as the United States. To comply with the regulations of the era, the Zero P2 was given large bumpers and various other structural modifications. It continued to use the Nissan L28E engine found in the original concept.
The Dome Zero P2 was introduced to the public in 1979 at the Chicago and Los Angeles motor shows. It was estimated to have a retail price of between $30,000 to $60,000 (USD). Like the original concept, the P2 failed to be homologated for sale in Japan and overseas, and never made it past the prototype stage.
Dome Zero RL
The Dome Zero RL of 1979 was a racing variant intended to publicize the road cars and to compete in the 24 Hours of Le Mans. It had an aluminum twin-tube monocoque chassis with a narrow track (52.7 inches) and a long body (16.4 feet) and was powered by a Cosworth DFV V8 engine. The Zero RL made its racing debut in 1979 at the 6 Hours of Silverstone, driven by Chris Craft and Gordon Spice, and finished in 12th place. Two Zero RLs contested Le Mans with the #6 car driven by Craft/Spice and the #7 by Tony Trimmer/Bob Evans. Both of the cars failed to finish the race. Subsequent versions of the Dome race car competed at Le Mans in later years. In the 1980 24 Hours of Le Mans the RL-80 was driven by Craft/Evans and did not finish. Craft/Evans failed to finish with the RL-81 at the 1981 Le Mans.
by Dan Vaughan