Super Taikyu was created in 1991 under the name N1 Endurance Series, drawing its regulatory framework from the FIA Group N production car regulations. The series divided competitors into classes primarily according to engine displacement and drivetrain configuration, a structure that reflects the original Group N philosophy of keeping cars recognisably close to their showroom counterparts. The ST-1 class sits at the top of this domestic hierarchy, accommodating the largest-engined and most powerful production-based machinery the series allows outside of its internationally homologated categories.
The full lineup of original classes runs from ST-1 through ST-4, with a fifth class, ST-5, added in 2010 to capture smaller-engined production vehicles. Together these five classes form the domestic core of Super Taikyu, running alongside the internationally recognised GT3, GT4, and TCR categories that have been incorporated into the series since 2011.
ST-1 eligibility is defined by engine displacement and drivetrain rules derived from Group N. Competing cars must remain close to production specification, keeping ST-1 philosophically distinct from the outright GT3 machines that contest the ST-X class. The balance between performance and relative affordability has allowed a range of Japanese domestic market models to appear in the class over the years, making ST-1 a showcase for high-displacement Japanese sports cars and grand tourers in endurance conditions.
Race formats in Super Taikyu vary by event. The series' flagship contest is the Fuji Super TEC 24 Hours, held annually at Fuji Speedway since its revival in 2018. Prior to that, the Tokachi 24 Hours, run from 1994 to 2008, was the series' longest race. ST-1 cars have competed across all of Japan's major circuits, including Suzuka, Autopolis, and Okayama International Circuit.
The ST-1 class has maintained a continuous presence throughout the Super Taikyu Series since the championship's first season in 1991. Its longevity makes it one of the most historically deep categories in Japanese domestic motorsport. Over more than three decades of competition the class has produced a champion's roll that tracks the evolution of high-performance production cars in the Japanese market.
The series as a whole is run on a pro-am basis, meaning ST-1 grids regularly blend professional and amateur drivers sharing the same machinery. This format differentiates Super Taikyu from the professional-only Super GT series and gives gentleman drivers the opportunity to compete at events such as the Fuji 24 Hours in the same class as experienced racing drivers.
Tyre supply for the series has changed several times across the ST-1 class's history. Yokohama supplied the series through 2017, Pirelli held the contract from 2018 to early 2023, Hankook took over for the remainder of that year, and Bridgestone assumed the role from 2024 onward following a manufacturing fire at Hankook's Daejeon plant.
The survival of the ST-1 class over more than three decades reflects the enduring appeal of production-based endurance racing in Japan. While the Super Taikyu Series has expanded considerably to include international GT3, GT4, and TCR categories, the original Group N-based domestic classes remain the series' foundational identity. ST-1 continues to serve as the headline category of that domestic structure, linking the championship's present to its origins in 1991.