All-new 'RX-9' rotary coupe to emerge 335kW turbo-hybrid range-extender – but not until 2020

Back in July we reported the latest rotary-powered RX-7 developments inside Mazda’s Hiroshima HQ and the fact the company has registered both the ‘RX-7’ and ‘RX-9’ names at the local patent office.

Since then various reports have further fuelled speculation that Mazda has not just one, but two rotary models in the pipeline.

As we’ve reported, it’s suggested that Mazda is planning the reveal of an all-new RX-7 rotary coupe in 2017, to celebrate the 50th anniversary of the debut of its first rotary model — the Cosmo Sports of 1967.

But there have also been rumours that Mazda will then launch a second rotary model – dubbed the RX-9 — in 2020 to celebrate Mazda’s 100th anniversary.

We can now confirm that Mazda does have two special projects on the table — one for 2017 and another for 2020 – but it appears they will both revolve around the same rotary model, the reveal and launch of which will be spread over a four-year period.

“We want to surprise everyone in 2017 with something special to celebrate the birth of rotary,” a senior Mazda executive told us.

“Then, to celebrate the company’s 100th birthday, we want to take it to another level in 2020,” he added, confirming separate celebrations for both anniversaries.

From what we’re hearing, Mazda will not launch two rotary cars, but stagger the reveal of concept and production versions over four years – not unlike Nissan did with its latest GT-R — to highlight its rotary heritage and generate maximum anticipation for its long-awaited rebirth.

It plans to kickstart the rotary dream in 2017 with the unveiling of a next-generation rotary concept car, and then realise that dream in 2020 with the reveal, launch and production of a belated replacement for the iconic RX-7, which we think will be called RX-9.

We know for sure that Mazda is developing a rotary engine for an RX-7 successor and has been doing so for the past decade. One source says that a Ferrari 550-resembling prototype surfaced briefly in 2004 on an RX-8 chassis.

“But that soon disappeared and the RX-7 project was put on hold until around 2006 when pretty much all of the company’s sports car engineers and designers were channelled into development of the new MX-5.”

Now that work on the fourth-generation MX-5 is done, Mazda has reallocated its senior R&D staff to the ‘RX-7’ rotary coupe project, since the relatively small Japanese car-maker only has the resources to build one sports car at a time.

The rendering you see here is an artist’s impression of Mazda’s born-again rotary coupe and incorporates the company’s new MX-5 design language as well as hints from our insider. And with Ferrari-esque styling cues up front and touches of BMW Z4 towards the rear flanks, we think it looks the business.

We’ve heard that a prototype based on a reinforced rear-drive MX-5 platform has been testing at a racetrack in northern Japan and its signature rotary exhaust note was unmistakable. A couple of months earlier, a turbocharged RX-8-based mule was also spied testing in Japan.

In a world of 370kW-plus sports cars, our source tells us that Mazda is targeting around 335kW for its RX-7 successor. “But to get there with a rotary engine is not easy,” he tells us.

With current rotary technology, the most power that a naturally aspirated engine can generate is around 225kW, says our source. “To get to the targeted 335kW, some significant extra devices are necessary.”

Rather than employ a revised version of the 1.3-litre 13B Renesis rotary from the discontinued RX-8, the new car will be powered by an all-new rotary already previewed by the larger, twin-rotor 16X concept engine.

But it will be assisted by the same range-extending technology seen in the Mazda2 plug-in hybrid concept last year, as well as a capacitor-powered e-turbocharger.

Our source has revealed Mazda engineers are working on a two-stage turbo system that incorporates an “electric turbo assist” function that engages at low rpm, and a standard exhaust-driven turbo that cuts in at higher revs.

“Engineers will employ a capacitor (a unit that stores power and discharges it on demand) to beef up the rotary’s ‘instability’ at low rpm, and when boost pressure rises, a standard turbocharger will engage to keep the flow of power coming,” said our contact.

This arrangement, we are told, more than solves the three main problems of the outgoing RX-8 rotary; namely poor fuel economy and emissions, excessive oil use and weak mid-range torque.

Even better, Mazda’s new rotary engine will produce prodigious power in a lightweight coupe that will tip the scales at around 1280kg. In addition to employing the next MX-5’s latest construction methods, engineers are also experimenting with “several carbon-fibre parts” to reduce weight and boost performance.

Image: Holiday Auto magazine