Mazda RX-8 - Development and Design

Development and Design

Development of the RX-8 can be traced to as far back as the 1995 Mazda RX-01 concept car, which featured an early iteration of the 13B-MSP engine. Naturally aspirated with side exhaust ports, this engine produced 210 hp (160 kW). As prohibited by Mazda's financial state at the time and the growing market interest in SUVs, the RX-01 never saw further development or production. However, a "skunkworks project" engineering team within Mazda kept the development of the 13B-MSP alive using MX-5 Miata chassis, eventually catching the attention of management, which at this time had come under heavy influence from Ford. Development of the 13B-MSP advanced and eventually led to the RENESIS moniker debuting along with the RX-EVOLV concept car which began to bear semblance to the production RX-8 with the "freestyle" rear suicide doors. Styling was developed via design competitions in Mazda tradition among its design studios in Japan, the US, and Europe. The project obtained official approval from management, and eventually the RX-8 concept car (design/engineering model) was produced and shown in 2001, closer resembling the production version. A near-production "reference exhibit" RX-8 was shown shortly thereafter at the 2001 Tokyo Motor Show, pending final approval for production. Production RX-8 closely resembles this vehicle save for minor trim details, and "job 1" began in February 2003 at Mazda's Hiroshima plant in Japan.

The RX-8 was designed as a front mid-engine, rear-wheel drive four-seat four-door coupé. The car has 50:50 front-rear weight distribution, and a low second moment of area that is achieved by mounting the engine behind the front axle and the fuel tank ahead of the rear axle. The front wheels feature classic independent double wishbone suspension, while the rear are independent multi-link. Weight is trimmed through the use of materials such as aluminium and plastic for several body panels. The rest of the body is steel, save for the plastic front and rear bumpers. The manual gearbox model uses a carbon fiber composite driveshaft to reduce the rotational mass (moment of inertia) connected to the engine. Power is sent to the rear wheels via a Torsen limited slip differential for improved handling. While it's not quite in the league as the last RX-7 in terms of raw performance, the RX-8 is considered its successor as Mazda's rotary engine sports car. Its layout and clever engineering, along with typical Mazda suspension tuning, have endowed it with excellent driving dynamics which have garnered much praise and numerous awards. It has also proven popular in Japan among car enthusiasts as well as aftermarket equipment manufacturers and professional tuners.

A prominent feature of the RX-8 is a pair of rear-hinged "freestyle" doors (similar to suicide doors) to provide easier access to the rear seats. The RX-8 has no B-pillar between the front and rear doors, with the leading edge of the rear door acting as a "virtual pillar" to maintain structural rigidity. Because of the overlapping design, the rear doors can be opened only when the front doors are open. Although by no means expansive, the RX-8's cabin was designed to allow enough room to house four adults, making it a genuine 4-seater rather than a 2+2.

The RX-8 was sold on exports markets including in Europe, whereas the RX-7 had been withdrawn from these markets after 1996 due to falling sales and thereafter only sold in Japan.