Mazda's rotary legacy

Sam Bisby

By: Sam Bisby

As masters of innovation, Mazda has a history steeped in creating new and wonderful ways to produce its range of cars and one of its most famous creations is now tipped for a comeback.

Set to be unveiled at the Tokyo motor show, Mazda has released a single image of the Japanese manufacturer’s initial design for a new sports car, and could mark the return of its iconic version of the rotary engine.

In celebration of this possible comeback, we look back at the best and most important rotary-powered Mazda’s.

Mazda Cosmo Sport

Creating its first rotary engine was a labour of love for Mazda, who installed a dedicated team of people to help develop and build its incarnation. Mazda had adapted the Wankel (stop sniggering at the back) set-up of the rotary engine, influenced by the German engineer Felix Wankel, and is a layout that is characterised by unique triangular shape of its rotor.

Following the mountain of research and trial and error from the 47 engineers, Mazda had finally commercialised the rotary engine and housed it in the Cosmo Sport, a car that combined unorthodox styling and a highly unusual powertrain under the bonnet. Its two-rotor layout was honed by Mazda following testing through its dealer network and the two-door coupe was eventually launched in 1967, with its Wankel unit producing a useful 110bhp from its 1.0-litre capacity and Mazda began its association with the rotary engine.

Mazda RX-7

Arguably, one of the best results from Mazda’s dedication to rotary technology was the RX-7 sports car. The original RX-7 saw the firm overcome adversity from the fuel crisis of 1974 when rotary-powered cars, among others, were labelled as gas guzzlers as they weren’t exactly fuel efficient in those days. However, Mazda ensured they would improve the fuel efficiency of its rotary engines by 40 per cent within five years.

Initial redevelopment then a cunning idea to reuse heat generated from the internal reactor saw a final improvement of 50 per cent to surpass its own target and in 1978, the first RX-7 was launched at the Las Vegas motor show. Marking a new era of rotary engines, the RX-7 went on to race in Le Mans and in the World Rally Championship, while actually achieving a class win in the 24 Hours of Daytona on its debut.

Probably the most recognisable version of the RX-7 is the third generation of the car, largely with the younger car fans after appearing in numerous video games and the Fast and Furious franchise. It was powered by a compact but potent 1.3-litre engine that produced a very sporty 252bhp that combined with the car’s lightweight 1218kg mass to boast a power-to-weight ratio of 210bhp/ton, while also offering a 50:50 weight distribution thanks to the packaging of that rotary engine.

Mazda 787B

In the extreme world of Group C racing, much was required to first of all finish a race and then win a race. Cars of this period were reaching speeds of up to 240mph on the straights of Le Mans, and in 1991, Mazda joined a collection of these iconic racing machines to take outright victory in the prestigious race with the outrageous and reliable 787B.

Mazda had tried and failed at Le Mans for nearly 20 years, but with the 787B Mazda had something truly special. The monstrous vehicle’s 2.6-litre four-rotor unit produced a whopping 697bhp at 9000rpm, while Mazda claims in qualifying trim the 787B could produce 845bhp. Again, this ensured a very competitive power-to-weight ratio that, along with its reliability, helped the car ace its rivals.

At the hands of Brit Johnny Herbert, German Volker Wilder and Frenchman Bertrand Gachot, the 787B was able to become not just the first Japanese car to win Le Mans outright but also the first non-piston engined car to claim such a victory. It is also the only car to ever achieve this, as rotary engines were subsequently banned from Le Mans.

Mazda RX-8

Not necessarily a direct successor to the RX-7, the RX-8 was another radical car to come out of Mazda’s further endeavours into rotary engines. After developments were halted on rotary powertrains in 2002 with the end of the RX-7, Mazda bounced back just a year later with the RX-8, complete with its new 1.3-litre RENESIS unit - RE as in ‘restart’ and NESIS being the latter part of Genesis.

Mazda further optimised the superb combination of compact sizing, lightweight design and high performance to create a new concept in the form of a true four-door, four-seater sports car. The highest performing RX-8 saw 250bhp going through a six-speed transmission and onto the rear wheels, while various other configurations were made available. A turbocharged version of the RX-8 was at one time in development, but Mazda came short of meeting EU efficiency regulations and the project unfortunately never made it into production.

The next generation

Although not confirmed by Mazda, its upcoming Tokyo show car is highly tipped to carry on from where the RX-8 left off but look more towards the RX-7 for its design influence, with a true successor to the sports car that met its end over 10 years ago constantly rumoured. Meanwhile, Mazda has said the original Cosmo Sport 110S will accompany the new concept on the manufacturer’s stand, igniting further confidence in Mazda bringing back the rotary engine.

In light of the announcement, Mazda claimed the car “clearly embodies the carmaker’s lineage”, while also stating that “Mazda is highlighting the brand’s unique approach to the joy of driving”, so you can be pretty sure that the legacy of Mazda’s rotary-powered cars will carry on through this new car. Those who may question whether its engine can prove to be efficient and economical have been reassured that the car will only make production if it can match the standards of other conventional powertrains.