Mazda RX-7 successor in the works

It’s one of the most anticipated models since the 2007 return of Nissan’s GT-R, but Mazda is still yet to officially confirm a rotary-powered replacement for the RX-7 and RX8 sports models.

However, the latest of a series of reports suggests that an RX-7-succeeding two-door sports coupe is under development at least, with the Nissan 370Z’s 86/BRZ-Porsche Cayman splitting market territory firmly in its sights.

An idea of what the model might look like has been created by master artist Theophilus Chin, based on Mazda’s Shinari concept that evolved into the current model 6.

According to Autoweek, industry buzz suggests that a lightweight two door coupe based on the upcoming 2015 MX-5 is being developed, with a next-generation rotary engine.

With the MX-5 expected to drop its price nearer to the 86/BRZ rear-drive performance bargains, a higher performing RX-7 is expected to target the 370Z’s upcoming replacement, which is also expected to lower its current $56,930 entry point.

The Mazda is yet to receive a production green light however, with a “no concrete plans” official line, but Autoweek reports that Mazda executives have made off the record confirmation of the development program.

A 2015-16 completion date has also been suggested, which would be a logical fit for the rotary engine’s 50th anniversary in 2017 or the RX-7’s 40th anniversary in 2018.

Mazda’s chief designer Ikuo Maeda is also the son of the design boss who oversaw the original RX-7’s development, and reportedly wants to see the new sports coupe reach production before he retires.

Mazda plans to use a smaller-scale rotary engine design as a generator for agricultural applications, and has explored its potential as a range-extending engine for hybrid vehicle applications as showcased in the Mazda 2 prototype driven by Carsguide late last year. The rotary used in this model is a 330cc single chamber design, unlike the twin-rotor 1.3-litre Renesis unit used most recently in the RX-8 that ended production in 2012.

The report suggests that a production Mazda sports coupe will not use a hybrid drivetrain and will be naturally-aspirated like the RX-8. The new model will also likely deliver significantly improved fuel consumption over the RX-8’s 12.9L/100km combined fuel figure.

A capacity of around 600cc per rotor has been suggested – slightly down from the RX-8’s 650cc – and it’s unclear whether twin or triple-rotors will be employed. A twin-rotor like the RX-8 is most likely, which would result in an overall capacity of around 1.2-litres.

Given the new engine’s efficiency focus, power output is not likely to climb significantly from the RX-8’s 170kW, with a realistic figure of about 186kW. However with the upcoming MX-5’s expected weight savings, such a figure could prove more than adequate in a coupe version of the same platform.

This reporter is on Twitter: @Mal_Flynn