| The importance of unsprung weight was not taken lightly- aluminium alloy was employed in the fabrication of every suspension component. |
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| Among the countless technological
innovations featured in the new RX-7, the suspension system is perhaps the most
noteworthy. Our aim was to realize a chassis that responds to driver input in a natural
and linear manner. We therefore eschewed the use of hydraulic or electronic control in
favors of a purely mechanical system in order to create the ultimate suspension system. A double wishbone design with optimum camber characteristics was adopted at the front and rear. This is the ideal layout for pure-bred sports cars where outstanding tracking performance and quick, yet linear, handling characteristics must be balanced at an extremely high level. The design itself is nothing new, in fact it is almost traditional for sports cars, however it was unthinkable for us to use this alone as the backbone of out technology. The A-shaped upper arms of the front suspension are fabricated from squeeze-forge aluminium and mounted directly to the highly rigid body shell. The L-shaped lower arms, which are subjected to higher loads, are made of forged aluminium and mounted to a steel cross-member. The upper Y-arms of the rear suspension are mounted on the same cross-member as the lower I-arms and trailing links. Toe-control links placed between the lower and upper arms, just ahead of the wheel axis, locate the hub supports. The I-arms, since they are subjected to heavy loads, are made of forged aluminium, while the hub supports are fabricated from squeezed-forged aluminium. It is obvious from the explanation so far that is not just another suspension system. We refer to it as the white suspension, taken from the colour of the aluminium. No matter how sophisticated the mechanism, absolute lightness is essential for suspension components since they are a major contributor to unsprung weight. Our relentless pursuit of light-weight constructions also manifest itself in the suspension components. Just by using aluminium, the total weight of the suspension system was reduced by 10kg comare to the previous model. The super-lightweight 16 x 8JJ alloy wheels each weight only 7kg which is comparable to many 14-inch wheel, and the exclusive, lightweight 225/50/ZR16 tyres are less than 10.5kg each. 1  2 |
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| The powerful, four-wheel anti-lock brake
system provides ample stopping power for this high-performance sports car. Since the
brakes also contribute to unsprung weight, the opposed four-piston calipers on the front
are made of aluminium. All four wheels feature ventilated rotors and the inner fins on the
front discs are staggered to improve cooling efficiency as well as to reduce weight.
Although the pedals do not contribute to unsprung weight, they are also aluminuim
resulting in a total weight reduction of 500g and the newly developed ABS actuator is now
3.3kg lighter than the previous type. The new RX-7 uses a track-and-pinion type steering system developed with the same philosophy as the suspension. The mounting bracket for the steering gear is integrated with the cross-member to increase stiffness and the joint of the steering-column is less articulated resulting in smoother movement. Engine-rpm sensitive, power-assisted steering prevents over assistance and a compact, lightweight integrated pump is employed. Even the rack bar is hollow to reduce weight even further. The net result is that each wheel assembly now weighs only 45kg. The outstanding attributes of the unique Four-Wheel Dynamic Geometry Control system are further enhanced by the exceptional tracking performance made possible by the lightweight suspension. |
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