Dome Co. Ltd, literally "child's dream", is a Japanese racing car constructor involved mainly in open-wheel and sports car racing.

karasu

In 1965, Minoru Hayashi built his first racing car, a rebodied Honda S600 coupe. Belonging to Tojiro Ukiya, it was called the "Karasu" (crow in Japanese), due to its shape. Built on a small budget and in a short time, the Karasu emphasized weight reduction and aerodynamics using FRP materials. The car went on to win its debut race at the Suzuka Clubman Race, despite Hayashi having no experience in racecar construction. In 1966 he went on to build the "Macransa", a more extensively modified Honda S800, to compete at the Japanese Grand Prix. This was followed by the "Kusabi" three years later, which was a Formula Junior racing car, and the "Panic" in 1971.

zero

The Dome Zero was a prototype sports car from DOME Co. Ltd that was exhibited at the 48th Geneva Auto Show in 1978. The Dome project was started by Minoru Hayashi in 1975, with the goal of producing sports cars using knowledge gained from auto racing. The Zero was to be their first production road car and Dome planned to produce a limited number for sale in Japan. Despite multiple prototypes and homologation efforts, the Zero was never approved by regulatory bodies for sale in Japan or overseas. As a result, the project was not commercially viable and the Zero never entered series production.

The Dome Zero represented a technological leap forward for small-scale Japanese automakers. The unusual design of the Zero required an extensive engineering process, incorporating newly designed components and off-the-shelf items from other Japanese auto manufacturers. It had a strikingly modern wedge-shaped exterior reminiscent of the Lancia Stratos Zero, Lamborghini Countach and Ferrari Berlinetta Boxer. It was rear mid-engine, rear-wheel-drive layout with a chassis of square-section steel tube. The 2.8L Nissan L28E SOHC straight-six engine produced 143 hp. This engine was also used in the Datsun 280Z and 280ZX. With this engine and a curb weight of 920 kg (2,028 lb), the Dome Zero offered a power-to-weight ratio that matched contemporary Porsche models. The prototype also incorporated a ZF 5-speed transmission, independent double-wishbone suspension and four-wheel disk brakes, mounted inboard at the rear.

jiotto caspita

The Jiotto Caspita is a prototype mid-engine sports car designed and manufactured by Dome in 1989. The car was billed as the "F1 on the Road." The original design of the car was done by Kunihisa Ito, who was the vice president and chief designer of Jiotto Design Incorporated.^[1] Its name is derived from the Italian exclamation "caspita".

The Caspita was displayed at the 28th Tokyo Motor Show in 1989. In light of positive reception, a limited production run of 30 units was considered, but never came to fruition. The project would die out in 1993 due to the collapse of the Japanese asset price bubble, which resulted in a lack of demand for sports cars.

The Mk. I Caspita was built with a detuned Subaru 1235 flat-twelve engine, a Formula One engine originally built by Motori Moderni for Subaru. It rated  450 hp and could accelerate the car from 0t-100 km/h in 4.7 seconds.  After the failure of Subaru's F1 effort, the 1235 was abandoned, leaving Jiotto without an engine supplier.

The Mk. II used a Judd GV V10 engine, with which it was capable of 585 hp. This, combined with a curb weight of between 1,240 kg  and 1,260 kg  gave the Caspita a claimed 0-100 km/h acceleration time of 3.4 seconds.

s101

The Dome S101, later upgraded and raced as the Dome S101 Hb, S101 Hbi, and the Dome S101.5, is a sports prototype built and designed for use in the LMP1 class of the 24 Hours Of Le Mans, and other similar endurance races. The car was the predecessor to the Dome S102, and the Strakka-Dome S103. The car had its racing debut at the 2001 Barcelona 2 Hours and 30 minutes, the opening round of the 2001 FIA Sportscar Championship, with the Den Blå Avis racing team.

Due to new regulations in LMP1 for the upcoming 2007 racing season, which meant that "Hybrid" rules LMP1 cars were to be barred from competing in any ACO Sanctioned event, Dome was forced to create a new variant of the car. In a bid to save costs, the lower half of the S101hb monocoque was retained, while a new double roll hoop assembly was attached, in place of the previously used single roll hoop, and air intake.

Racing for Holland re-entered their Dome chassis into the 2002 FIA Sportscar Championship, securing 1st in the Teams Championship. Dome won the 2002 FIA Sportscar Constructors Championship.

s102

The Dome S102, later upgraded and raced as the Dome S102.5, is a sports prototype built and designed for use in the LMP1 class of the 24 Hours Of Le Mans, and other similar endurance races. The car is the successor to the Dome S101, and its later evolutions. The car was unveiled on the 21st of March 2008. The Dome S102 is designed to be the successor to the open-topped Dome S101, featuring improved aerodynamics compared to the final iteration of the S101, with 9% Less Drag, as well as 11% More Aerodynamic Efficiency. The car was developed in-house, with 2 wind-tunnel models. 

Over the winter of 2011 the car was updated in preparation for it's return to competition, with redesigned front fenders, wider front tyres, as well as an engine cover fin. The Judd V10 was replaced with a smaller 3.4L Judd V8, with the car requiring a spacer plate in the engine bay to accommodate the newer engine. On the 2nd of February 2012, it was announced that the Dome S102 would return to competition, upgraded as the Dome S102.5.

rl

1979

The RL was designed by Dome head of design, Masao Ono. The car was meant to compete in the 24 hours of LeMans and hence it was designed with low drag in mind. The front of the car was very narrow and it was around 5 meters long in order to reduce drag, unfortunately all this did was make the car a handful to drive, it suffered with major high speed instability.

At its first appearance at the 1979 24 Hours of LeMans, 2 cars were entered, both cars used 2.9 litre Cosworth engines however one car ran with 450hp while the other with 415hp. The cars qualified poorly in 15th and 18th, in the race however there were promising signs at first when one of the cars had gained 10 positions after the first hour however the cars didn’t last particularly long and Dome ended up retiring both cars before the night.

The car would be redesigned and entered agian for the 1980 however a gearbox problem early on in the race would mean that the car would cross the line in dead last. Another entery for the 1981 event would end in a DNF for the team.

After its disaster attempts at LeMans funds would run low for the team and the project would be stopped with Dome continuing to race Toyota built prototype cars throughout the eighties.

f105

In 1995, the former team manager of the Minardi Formula One team, Tadashi Sasaki, joined Dome. Sasaki organised a Formula One project which was announced in the autumn of that year. Akiyoshi Oku, who had designed the F104 F3000 car, began work on the new F105 chassis in the summer of 1995. Sasaki's influence was crucial, as he was in a position to buy Minardi's old gearbox and hydraulic systems to use on the F105. The transmission was a six-speed semi-automatic gearbox designed by Xtrac, and had previously been used, in addition to the Minardi team, by the unraced DAMS GD-01 car and formerly in the Simtek S941 chassis during the 1994 season. In terms of the car's engine, Dome's success with Mugen Honda engines in the Japanese racing scene ensured that the F105 would be powered by the company's MF301 V10 engine, as used by the Ligier team during the 1995 Formula One season. Dome's close association with Mugen, a subsidiary of Honda, sparked rumours that the Japanese company was using the Dome F105 project as a discreet evaluation of a return to Formula One after its own withdrawal from the sport at the end of the 1992 season. Dome has denied that this was the case, insisting that it was an independent effort.

Dome planned to establish a European test base during the summer of 1996 and run at several European circuits on the calendar of the 1996 Formula One season, but this plan never came to fruition due to a shortage of funding. The team did, however, test at Suzuka shortly after the season-ending 1996 Japanese Grand Prix at the circuit. Hattori set a best time of 1:46.270, which was more than seven seconds slower than Jacques Villeneuve's pole position time of 1:38.909 set in the Williams FW18 chassis. It was also 0.3 seconds slower than the 107% cut-off mark for qualification, although journalist Sam Collins speculates that a faster time could have been set with a top-line driver.

Dome's lack of sponsorship eventually forced it to cancel its plans to enter the 1997 Formula One season in the autumn of 1996. Nakano left the project and was promoted to Formula One with the Prost (formerly Ligier) team, which was equipped with Mugen engines. Sasaki attempted to obtain funding to compete in the 1998 season and beyond from a variety of sources, including the Nigerian Prince Malik Ado Ibrahim, who eventually invested in the Arrows team instead after negotiations with Honda for a fresh supply of engines fell through.