Jiotto Caspita: The F1-Powered Japanese Supercar You Probably Never Knew Existed

During the supercar craze of the 1980s and 1990s, several carmakers dubbed their most ambitious creations "Formula 1 cars for the road". However, few were close to living up to that slogan.

Though McLaren's first street-legal production model was called F1 and became arguably the best supercar of all time, it was powered by a bespoke version of a mass-produced BMW V12. Furthermore, it was innovatively built but didn't quite borrow any important technologies from Formula 1.

The Ferrari F50 might be the only production supercar of that era that came closest to that statement. It used a Formula 1-derived pushrod suspension system, and its V12 engine was a modified version of the Tipo 036 that powered the 1990 Ferrari 641 Formula 1 car.

There were also two Japanese supercars that, although never made it into production, lived up to the "F1 car for the road" slogan.

The most famous was the 1992 Yamaha OX99-11, powered by the company's F1 engine with the same name (also known as the worst F1 engine of all time). The second, forgotten even by some JDM enthusiasts today, was the Jiotto Caspita, another wild supercar with a mid-mounted F1 engine put together by a lesser-known company.

Dome's second attempt to build a Japanese supercar

The Caspita started as the dream car of Yoshikata Tsukamoto, president of lingerie and underwear giants Wacoal and Minoru Hayashi, the president of race car builders Dome.

Through their respective companies, the two supercar enthusiasts took control of the design house Jiotto during the 1980s and tasked it with designing Japan's "F1 car for the road". Once the final design was approved, Dome handled the manufacturing.

Although virtually unknown outside of Japan back then, Dome was no stranger to building supercars. During the 1970s, the company, which had no prior experience producing cars, developed the Dome Zero. A futuristic mid-engine Japanese Lancia Delta, it didn't make it into production but transformed Dome into a reputable race car manufacturer.

One of the most extensively developed, over-engineered cars of its era

The supercar became Jiotto's most ambitious project. The company's stylists submitted around 200 design proposals, of which only three made the final cut.

The winning proposal was submitted by Jiotto's founder, vice president, and chief designer, the experienced Kunihisa Ito, who previously worked for GM, Ford, Mazda, and Nissan. His Group C prototype-inspired design morphed into 1/5 scale mockups used to further the car's looks. Then, full-scale mockups were comprehensively tested in Dome's and JARI's (Japan Automobile Research Institute) wind tunnels.

The result was a stunning, aerodynamically-efficient body with gullwing doors and an electronically-retractable rear wing. It was wide, low-slung, and looked way ahead of its time.

Its monocoque chassis was fabricated by Mitsubishi Rayon using a highly-advanced technique meant to slash weight and improve the structure's rigidity to unprecedented levels. The technique involved wedging aluminum sheets between two carbon fiber layers and curing them in an autoclave. The whole process was repeated 15 times in two months to create the lightest, most rigid chassis a Japanese car had ever used.

The double wishbone suspension's layout was inspired by Group C prototypes and Formula 1 cars of the era, but for increased comfort on public roads, it used electronically-controlled shocks that adjusted the height and stiffness based on the driver's input.

Formula 1 power

Though Dome built the car, Hayashi and Tsukamoto decided to call it Jiotto since both their companies owned the design firm. But, like all great cars, it needed a model name, so they went for the Italian exclamation "caspita!" (which translates to Woh!)

The Jiotto Caspita was unveiled at the 1989 Tokyo Motor Show. Apart from its gorgeous looks, it impressed with the Subaru 1235 Formula 1 lump mounted in the middle.

Mated to a six-speed gated manual, the engine in question was a state-of-the-art 3.5-liter flat-twelve detuned to 450 hp and 268 lb-ft (363 Nm) of torque to comply with emission standards. Former Italian race driver Carlo Chiti's Motori Moderni built the race-bred boxer for Subaru's 1990 Formula 1 program, but as it would turn out, it was an epic failure.

It seems that it didn't do too well in the Caspita prototype either because the improved Mk II (built in 1993) dropped the Subaru-branded boxer for another F1 unit.

In this upgraded Caspita, Dome packed the much more successful and reliable Judd GV V10. The new powerplant was also mildly detuned but still capable of revving up over 11,000 rpm while spitting out 585 hp and 276 lb-ft (374 (Nm) of twist.

With this new engine, the Caspita was reportedly capable of accelerating to 62 mph (100 kph) in just 3.4 seconds, reaching a top speed that exceeded 202 mph (325 kph).

Killed by the Japanese asset price bubble

So what happened with this excellent car between 1989 and 1993?

Well, legend has it that Dome was obsessed with developing the ultimate supercar. The engineers wouldn't settle for anything less than perfect, and since the Subaru boxer-12 was far from it, they needed time to find a suitable engine and make it reliable enough for a production car.

Moreover, they got wind of McLaren's F1 project, so they put in even more development time to make the Caspita better overall.

The Mk II prototype finished in 1993 embodied Dome's vision for the ultimate "F1 car for the road". But, although a production run of 30 units was considered when the bookkeepers ran the numbers, they just didn't add up. The Japanese asset price bubble ravaged the country's economy, which sent shockwaves around the globe. The demand for supercars dropped, so a newcomer like the Jiotto Caspita stood no chance.

Therefore, the project ended, and the two prototypes it yielded became museum pieces. The Mk I currently resides at Japan's Motorcar Museum in Komatsu, while its sibling can be admired in Dome's own museum located in Maibara.

If you want to learn more about this amazing Japanese supercar, we recommend watching the YouTube video below by ispeedonthe405. The car specs are presented in English, but interviews with the test drivers are conducted in Japanese, and the video has no subtitles.