Ron Tauranac had co-founded Brabham with Jack Brabham in the 1960s and brought considerable engineering expertise to his new venture. The Ralt name had a personal history: in the 1950s Tauranac had built a series of specials in Australia, including the Mk1 powered by a 1,932cc Norton engine, a sports car for his brother Austin, and the Mk4 using a Vincent-HRD V-twin that attracted enough attention to prompt a small production run of five cars. These early efforts gave Tauranac a foundation in practical car construction before he entered professional motorsport.
Tauranac formally re-established Ralt in 1974. The first modern product was the RT1, a simple and adaptable car used in Formula Two, Formula Three, and Formula Atlantic between 1975 and 1978. Its successor, the RT2, was developed for Formula Two in 1979 and initially built for the Toleman team; three further cars went to private owners, including a single entry for the revived Can-Am series. Toleman subsequently developed their own TG280 design based on the RT2, which was later licensed to Lola and further modified by Docking-Spitzley.
The RT2 served as the basis for a family of derivatives: the RT3 for Formula Three, the RT4 for Formula Atlantic, and the RT5 for Formula Super Vee. In 1980, Honda asked John Judd's Engine Developments to produce a Formula Two engine for the works Ralt team, beginning a partnership that proved exceptionally fruitful. The works F2 cars, carrying the RH6 designation from 1980 to 1984, won 20 championship races and took the F2 title in 1981 with Geoff Lees, in 1983 with Jonathan Palmer, and in 1984 with Mike Thackwell.
The RT4 became especially prominent in Australian single-seater racing. Roberto Moreno drove an RT4 to victory in the Australian Grand Prix in 1981, 1983, and the final running of that pre-World Championship event in 1984. Alain Prost won the 1982 Australian Grand Prix in an RT4. The grid in that era also included Formula One World Champions Alan Jones, Nelson Piquet, Keke Rosberg, and Niki Lauda. John Bowe used the RT4 to win the Australian Drivers' Championship in 1984 and 1985, and Graham Watson — Ralt's Australian importer — won the 1986 championship in the same car.
The RT3 entered service as a ground-effect Formula Three car in 1979 and was developed annually through 1984, becoming the dominant chassis in the formula. Ayrton Senna won the 1983 British Formula Three Championship driving an RT3. When flat-bottom regulations came into force in 1985, the asymmetric RT30 replaced it — a car notable for carrying its radiator in a single sidepod while a deformable structure panel occupied the opposite side. Development continued through the RT31 (1987), the honeycomb-and-carbon RT32 (1988), and subsequent RT33 through RT37 models, which ran through to 1993. Though later variants were less competitive in international Formula Three as teams migrated to Dallara, the basic monocoque proved extremely durable in hillclimbing.
When Formula Two was replaced by Formula 3000 in 1985, Ralt introduced the RB20, a development of the RH6/84 fitted with a Cosworth DFV. The car won four races in the inaugural International F3000 Championship with Thackwell and John Nielsen. A simpler, cheaper successor, the RT20, followed for 1986 using an aluminium tub; a Honda-powered works car won one race while customer cars entered by Pavesi Racing took four more victories through Pierluigi Martini and Luis Pérez-Sala. The RT21 appeared in 1987 with additional honeycomb elements, and Roberto Moreno and Maurício Gugelmin each won once for the works team.
By 1988, Lola and the newcomer Reynard were beginning to overwhelm the F3000 market. Ralt's carbon-fibre RT22 achieved little success, and in autumn 1988 Tauranac sold the company to the March Group for slightly over one million pounds. The Ralt name continued briefly under March's ownership: the RT23 appeared in 1991, and Jean-Marc Gounon won at Pau in an RT23 entered by Mike Earle's team; an updated RT24 built by Nick Wirth's Simtek company raced in 1992 before Ralt withdrew from F3000 entirely. Used Ralt F3000 cars found a second life in Australia's Formula Holden category from 1989, fitted with a 3.8-litre Holden V6 engine.
The RT40 and RT41 were Formula Atlantic derivatives of the later F3 cars. Jacques Villeneuve, who would win the 1995 Indianapolis 500 and the 1997 Formula One World Championship, was among the many CART and IRL drivers who developed in these cars. When the RT40 was phased out of the Pro Atlantic series in 1998 in favour of the Swift 008a, many examples continued racing in SCCA competition, with the type remaining competitive more than a decade after its introduction.
After Ralt's sale, Tauranac continued designing racing-school cars for Honda, a Formula Renault car, and undertook consultancy work for the Arrows Formula One team. Ralt Australia was managed by New Zealander Graham Watson until his death in 2009. The Ralt name was later acquired by enthusiasts Andrew Fitton and Steve Ward in the early 1990s following a management buyout of the March Group, and F3 cars bearing the Ralt name continued to appear occasionally in subsequent years.
Ralt's legacy rests on its consistent ability to build straightforward, fast, and well-priced customer cars across multiple formulae for more than a decade. The company's partnership with Honda in Formula Two produced some of the most dominant works-supported cars of the early 1980s, and its Formula Three cars provided the competitive chassis through which Ayrton Senna announced himself to the world. In Australian motorsport, the RT4 connected Formula One-calibre drivers to a national series at a pivotal moment in that country's racing history.