The Revolutionary Mazda RX-8
Published: 20th November 2002
The Mazda RX-8 is instantly distinguished by its "freestyle" door system. The two rear-hinged rear doors open towards the back of the car, in the opposite direction to the front-hinged front doors. Due to this design, which dispenses with centre pillars, the Mazda RX-8 combines pure sports car styling with the practicality of four doors and four seats.
While there is plenty of space for four adults, the new Mazda RX-8 achieves its sports car character via a front engine/rear-wheel drive layout and a design that reflects the designers’ quest for sportiness without compromise.
With short overhangs front and back plus distinctive bumpers and aggressive bonnet line, the Mazda RX-8 shows its performance potential. The familiar Mazda pentagonal grille acts as an air intake. The compact Renesis rotary engine allows the A-pillar to be positioned forward and given an acute angle, visually shifting the car’s centre of gravity and vehicle mass towards the rear.
The Renesis engineers were given the task of developing an engine with approximately the same power output as the bi-turbo 13B engine. However, they also concentrated on building an engine with lower fuel consumption and emissions.
These targets have been achieved with the new Mazda Renesis engine. The water-cooled unit – with two rotary pistons and combustion chambers each with 645 cm³ displacement – produces between 240 hp and 250 hp at 8500 rpm. The engine’s maximum torque of 220 Nm is achieved at 7500 rpm, making Renesis the most powerful rotary engine without a turbocharger. It requires 50 per cent less oil and 40 per cent less fuel than its predecessor. The engineers also overcame the problem of high emissions, which was associated with older rotary engines. The Renesis emits less than 19 grams CO, 22 grams of HC and 14 grams of NOx, and achieves Euro Stage IV.
Including all its ancillary systems, Renesis is roughly as large as a four-cylinder in-line engine. The engine block is only 338 mm high and nearly as high as the transmission. The compact rotary engine, a long wheelbase of 2.70 m and space-saving sport seats allow for generous amounts of interior space. Head, shoulder and knee room are comparable to that of conventional sports saloons. The new Mazda RX-8 chassis sits on 18-inch wheels with 225/45 ZR 18 tyres, while the double A-arm suspension system delivers excellent handling characteristics. The car is equipped with a six-speed manual transmission, ABS and DSC.
The Mazda RX-8 employs an engine housing with a closed cross-section, which contributes to chassis stiffness. While most vehicles with a front engine and rear-wheel drive layout require drive shafts with central shaft bearings to provide stiffness, the distance between the RX-8’s transmission and differential is short enough to require only a single drive-shaft made of carbon composite, which saved designers overall weight.
For the interior, Mazda designers chose a mixture of modern
and traditional. The speedometer and tachometer are of classic
design. The tachometer has its zero position at six o’clock,
appropriate to a car with high rpm. All controls are within
easy reach of the driver and standard safety features include
intelligent front and side airbags.
