Posted here today: http://www.themotorreport.com.au/553...-2017-yamamoto

Mazda will bring back the much-loved RX-7 in 2017, with less weight, less complexity and a greater emphasis on driver involvement.

Speaking to TMR at the local launch of the facelifted MX-5, Mazda Motor Corporation's sports car chief Nobuhiro Yamamoto said that the return of the RX-7 will mark 50 years since the introduction of Mazda's first rotary-engined car, the Cosmo Sport, in 1967.

By the time the next-generation model arrives, it will have been 15 years since the RX-7 departed Mazda showrooms.

Production of the FD3S RX-7 ended in 2002, with that model built purely for the Japanese domestic market. Local RX-7 imports ceased in 1998.

Yamamoto was the powertrain head for the FD3S, and has a lot of fond memories of that car. He was also involved in the RX-7's win at Bathurst in 1992 - the last time he'd set foot in Australia.

As you would expect, bringing back the RX-7 has been high on his agenda.

However Yamamoto stressed that the new model wouldn't quite follow the lead of the FD RX-7. Asked if the next-generation RX-7 will feature forced induction, Yamamoto replied "maybe not".

"At this time it has not been determined. Maybe later in life it will be turbo, but to start with maybe not," he said to TMR.

Instead, Yamamoto favours a naturally-aspirated development of the new 16X rotary engine, which was unveiled in 2007 but has yet to find its way into a production car.

Displacing 1.6 litres (the previous-generation rotary, the 13B/Renesis, only displaced 1.3 litres), Yamamoto says the 16X is capable of up to 300 metric horsepower (220kW) in a naturally-aspirated configuration.

Yamamoto added that, with the use of a special catalyst, the engine will have no problem meeting the ultra-restrictive Euro VI emissions legislation that will be in place by 2017.

As the man who designed the Le Mans-winning Mazda 787B's R26B rotary engine, which developed 700hp from just 2.6 litres, Yamamoto should know a thing or two about extracting the most from a rotary.

Key among Yamamoto's powertrain requirements was throttle responsiveness and linearity of power delivery.

He told TMR that the stepped power delivery of the FD RX-7's sequential twin-turbochargers was not ideal for a sports car and that a larger single turbocharger would result in too much throttle lag. Therefore, a naturally-aspirated rotary is the best solution.

But while 220kW might sound low compared to many other modern sports cars, Yamamoto says that the new RX-7 will be light enough to make the most of its power.

While he was coy about the RX-7's target weight, he said it "would definitely be lighter" than the 1310kg FD RX-7, and "probably around the weight of the Toyota 86" (1250kg).

Expected to be built atop a variation of the next-generation MX-5's platform, the new RX-7 will employ a range of weight-saving technologies to keep its mass down.

Yamamoto said that aluminium body panels will be used extensively, although more exotic materials like carbon fibre won't be due to their greater cost and more energy-intensive manufacturing processes.

It won't, however, be anywhere near as light as its MX-5 brother, which is expected to weigh around 1000kg when it debuts in 2014.

The RX-7 will also be noticeably larger than the MX-5, with a stretched wheelbase to accomodate a pair of small rear seats for the Japanese market.

As with the previous generation, the new RX-7 will be a two-seater in Western markets.

Yamamoto also told TMR that hybrid or EV powertrains were not suitable for a car like the RX-7.

He said that although KERS-like hybrid systems and all-electric powertrains were capable of delivering big torque, their smoothness and near-silent characteristics didn't deliver much in the way of driver enjoyment.

"For a pure sports car, it must be internal combustion," he said.

Yamamoto says that the RX-7 will be a premium product, and will likely wear a pricetag that's higher than cars like the 370Z.