Mazda, the only car company to have kept faith with Wankel's vision, plans to celebrate the anniversary by launching the stunning RX-8 rotary-powered sports car next summer...

The Rotarway

The rotary motor's back and it's in the most exciting car to emerge from Mazda in a decade: the blitzing RX-8. We go under the skin of the new star.

August 13 this year marks the centenary of the birth of Felix Heinrich Wankel, inventor of the Wankel rotary engine. The same month of August, however, also sees the end of production for the third-generation FD-3S RX-7 in its final form as the Spirit R, a special limited-edition run of 1500 units reserved for the Japan domestic market.

Mazda, the only car company to have kept faith with Wankel's vision, plans to celebrate the anniversary in the best way possible - by launching this stunning RX-8 rotary-powered sports car next summer.
For all its compactness and freedom from vibration, the Wankel engine has a reputation for difficult-to-manage emissions and uncompetitive fuel economy. But rotary enthusiasts needn't have fretted - Mazda has developed a new, normally aspirated rotary engine for the 21st century called the Renesis.

As if this unique powerplant isn't distinction enough, the four-seat RX-8 also features the eye-catching 'suicide' (Mazda calls them 'freestyle') rear doors which originally appeared on the RX-Evolv concept car in 2000. The front doors open forwards as normal, but the smaller back doors pivot from their rear edges, like many a vintage saloon's. With the elimination of the B-pillars, this arrangement provides unusually easy entry and exit for rear-seat passengers in what is otherwise a compact modern coup‚ body.

The production version of the RX-8 will make its first public appearance at the Detroit Auto Show early next January, and the first cars will roll off the line in April prior to a June or July release in major right-hand drive markets. Full details of the car won't be released until then, but we've been able to piece much of the story together from a close look at the RX-8 concept - unveiled at Detroit this year - and from answers to (some of) our questions supplied by Mazda Motor Corporation HQ in Japan.

DESIGN AND BUILD
The new Renesis engine is even lighter and more compact than its predecessor, measuring just 338mm in height. It's mounted 40mm lower and set 60mm further back than the RX-7's too, helping to endow the RX-8 with 50:50 weight distribution and a low centre of gravity. The 'front-mid' engine location and long 2700mm wheelbase also ensure - Mazda claims - rapid responses to steering inputs.

Removing the B-pillars presented the RX-8 designers with a number of structural challenges; the first of which was to retain the high degree of torsional stiffness necessary for precise, predictable handling and a good secondary ride quality. Key to this is the car's high transmission tunnel, the upper part of which houses what Mazda refers to as a backbone frame, which links the front and rear bulkheads. This functions as the principal structural element of the chassis and has allowed the gauge of metal to be reduced elsewhere.

Side impact protection was another concern, which has been addressed by designing the front edge of the rear door to act as the primary load-bearing structure in the event of a side-swipe. In fact, Mazda claims superior side impact performance to a typical saloon, although it declines to say how it expects the RX-8 to fare in Euro NCAP testing. Double door latches prevent the rear door being opened while the front door is closed.

CABIN AND EQUIPMENT
Wherever you sit in the RX-8, it gives the impression - entirely proper for a sports car - that, although not cramped, its interior is compact. From the driver's seat, the view out over the three main dials is almost letterbox-like as a result of the low roofline and forward A-pillars, but if anything this results in more focused attention on the road. Glancing around those thick screen pillars will have to become a habit in town driving though. Atop the high transmission tunnel, the stubby gearlever is perfectly placed.

Rear legroom isn't sufficient for a six-foot passenger to lodge behind a six-foot driver, and rear headroom is also marginal for taller occupants. However, Mazda is probably content for the RX-8 to serve only as short-haul accommodation for four adults and longer-haul accommodation for two adults and two children. Younger kids probably won't appreciate the high body line and small rear side windows which, even when you're seated high enough, don't offer much view of the world outside.

The striking yellow body colour of the RX-8 concept is echoed inside by the yellow instrument binnacle, yellow leather on the steering wheel and yellow leather inserts in the front and rear seats. This colour co-ordination won't survive to production - there will more likely
be three leather trim options in black/black, black/red and terracotta. Fine fabric trim will be available for those who don't want cow hide.

Styling references to the Wankel engine, in the form of rotor-shaped
convex-sided equilateral triangles, abound internally as well as externally. The starter button, gearknob, seat backs and rear armrest catch-all carry this shape, as do the sill plates. Not all these will be carried through to production - you can overdo a good idea - but some will remain. The low-mounted triangular reversing light won't be one of them.

The generous standard equipment will include air-con and a seven-speaker Bose audio system. Boot volume is only 250 litres, just nice for two sets of golf clubs.

ENGINE AND TRANSMISSION
Although Mazda has stated publicly that the RX-8 will be fitted with only a 247bhp version of the new Renesis rotary, Autocar has established that there will actually be two engine variants on offer: the top 247bhp unit and a 189bhp alternative. Both have a capacity of just 1.3 litres. According to Mazda's specifications, the more powerful unit delivers its peak power at a high 8500rpm and its peak torque of 215Nm at an also high 7500rpm. Equivalent figures for the lesser engine remain secret, as do details of the differences that account for its reduced power.

Biggest change relative to the RX-7 powerplant is that the Renesis engine is normally aspirated, whereas its predecessor used sequential twin turbos. Despite this, their power outputs are virtually the same, thanks principally to the engine's complex induction system. Three intake ports are now provided for each of the two rotors and these incorporate electronically controlled shutter valves that improve volumetric efficiency (cylinder filling) by adjusting the velocity of the inlet charge in three stages. Twin electronic throttles are also featured, which Mazda claims give more accurate inlet control, and the new resin intake manifold has been designed to minimise air resistance.

Torque curves are not yet available, but one of Mazda's stated aims in moving away from forced induction has been to improve flexibility, so those high engine speeds for peak power and torque may be deceptive. A six-speed manual gearbox will be fitted to 247bhp cars and a five-speed manual to the 189bhp model.

Even though (in show car form) the RX-8 is only 140mm longer, 10mm wider and 110mm higher than the RX-7, its kerb weight is bound to be significantly higher. So a blunting of performance looks inevitable, even allowing for an improved torque spread and a closer set of gear ratios. Despite this, a sub-6.0sec 0-100kmh sprint and 240kmh-plus top speed seem likely for the 247bhp version.

SUSPENSION, STEERING, BRAKES
Assisted rack and pinion steering is no less than you'd expect, but Mazda's choice of electronic power steering in preference to the hydraulic alternative - presumably to save weight - is risky given the less than enthusiastic reception such systems have received in the past.
Suspension is by double wishbones at the front and a multi-link system at the rear. The reduced size of the new engine has freed up space for longer front suspension arms, facilitating improved control of wheel camber and track change. Use of a multi-link rear set-up will have allowed Mazda to tune in subtle amounts of rear steer to sharpen and stabilise the car's handling. Any temptation to use adaptive damping has been resisted - the damper rates are fixed.

The show car's 225/45R18 tyres will be carried over to production, at least as a factory option, but the fact that the four disc brakes have been dimensioned to fit within a 17-inch wheel tells its own story. Whether the racing-style, opposed-piston aluminium calipers will be retained is unclear. Because of the difficulty of incorporating a handbrake, they are unlikely to survive at the rear.

A newly developed stability control system is fitted as standard - whether it can be switched off hasn't been clarified.

COST AND MARKETING
Signs are that the RX-8 will cost a little less than the RX-7 did, with the price difference depending on engine and cabin options. Mazda plans to specify a high level of equipment as standard for all markets including Asean - with options limited to items such as satellite navigation - and will clearly target enthusiast drivers who, typically because of a young family, cannot justify buying a traditional two-seat sports car.

VERDICT
If you've got it, then you've got to flaunt it. Far from killing off the rotary engine, as some predicted it would, Mazda has breathed new life into the Wankel motor by designing a car that proclaims its individuality in the clearest terms. Even if you have no idea what a rotary engine is and the styling references to it zip over your head, no one will fail to notice the RX-8's unique design and positioning.

Just how the RX-8 will rate as a driver's car, as opposed to a head-turner, is more difficult to judge at this stage. It shrinks around you when you sit in it, promising the intimate driving experience of a genuine sports car. But Mazda's progressive softening of the MX-5 in recent years and those cramped rear seats may indicate that a more relaxed GT feel has been the real intention.

Also uncertain is the prospect of a convertible, although with all that body stiffening already in place and the Californian market high on Mazda's hit list, it has to be a strong possibility a couple of years down the line.

In association with Autocar Asean Edition