Mazda "hoisted themselves on their own petard" according to the judge in my case when they stated that "Mazda's goal in building the RX-7 was to build the Ultimate Sports Car." This removed any defense that attacked the way I drove my 1993 RX-7 R1. Here is the complete marketing literature on the 1994 RX-7 from Mazda, showing in even more vivid detail just how much Mazda encourages sporty driving of their flagship sports car. Here's the quote I love best:
But a more important measure will be the test you'll give it on the road. Or the race track.
There's nothing else like it. Fast. Lightweight yet strong. Supremely responsive. The Mazda RX-7 exists for one reason only: to offer the genuine enthusiast the pure driving thrill that would otherwise be found only in a race car.
The RX-7 marks the return of the pure sports car, a car with no design tradeoffs that would compromise its mission. Its race-car heritage is found in its every facet, from the unique rotary engine to extensive weight-saving measures. It's a definitive expression of Kansei Engineering, our deeply rooted philosophy that emphasizes a total harmony between driver and automobile. It's a philosophy that harnesses all the power of the latest supercomputers, yet relies as well on the insights of people, on their feelings and emotions. And on engineers who can design from the heart as well as the head. One measure of how eloquently this car speaks to true enthusiasts can be found in such honors as being named Motor Trend's 1993 Import Car of the Year. But a more important measure will be the test you'll give it on the road. Or the race track.
To give the Mazda RX-7 the feel of a race car, we designed it like one. We started out with a racing legend, the unique Mazda rotary engine, much lighter and more compact than piston engines of comparable power. The rotary makes the rest of the car possible, and the RX-7 is the only new rotary-powered car you can buy.
And because weight is the enemy of performance, we subjected every part, every design of the RX-7 to intense and thorough weight-reduction scrutiny-but never at the expense of structural strength. In pursuit of every last extra gram, we even drilled out the aluminum brake and clutch pedals and shortened the spark plug lead wires.
Thanks to this weight-conscious engineering, the RX-7 comes in at just 11.1 pounds for every horsepower, helping to put it in the front rank among the world's fastest production sports cars. Even more important, it delivers the overall performance and feel previously reserved for hand-built exotics. Or for a race car.
Specially tuned for only the most dedicated of enthusiasts, the RX-7 with the R-2 Package goes even further toward giving a taste of purebred racing machinery. On the track the R-2 will reward the skilled driving enthusiast with an extraordinary degree of responsiveness at the limit. Aero enhancements include a large front air dam and "floating" rear wing, designed to increase downforce on the car and even further improve stability at high speeds. Underneath, the shock absorbers are tuned more firmly, and there's a shock-tower brace across the engine bay, additionally stiffening the structure. You'll feel the difference both in transients, such as S-curves, and in absolute cornering ability. The package also adds a second engine oil cooler and dedicated air ducts to help cool the front brakes. And to help you take full advantage of the added potential, the RX-7 R-2 is fitted with the ultra-high-performance Pirelli P-Zero tires, Z-speed rated.
Power all alone, no matter how dramatic, cannot by itself define a pure sports car. Equally important is how effectively you can use that power. And while factors such as body rigidity and aerodynamics come into play, the car's essential road personality is determined by its suspension. Here, the RX-7 stands apart, setting new standards for vehicle dynamics by providing unprecedented levels of agility, response, and balance. Plus a high degree of communication between driver and road.
A visual work of art, the suspension was created specifically and exclusively for the RX-7. And after you sample its abilities, you'll think we also engineered all the roads just for the Mazda RX-7.
Engine, transmission, driveshaft, and differential are all coupled together by a highly rigid Power Plant Frame, a Mazda design that isolates drivetrain vibrations and eliminates torque twisting of the structure from drivetrain forces. The tangible benefit is precise and instant throttle response.
The basic suspension is fully independent, a double-wishbone type at all four wheels, plus concentric coil springs and gas-filled shock absorbers. The RX-7 further enhances the basic concept by adding toe control, both front and rear, to improve agility and feel in cornering. Both the front and the rear suspensions are mounted on subframes that are rigidly bolted to the body structure.
The rear double wishbone utilizes an upper A-arm and lower multiple links that neutralize toe-out forces in cornering to give the RX-7 maximum agility. The rear shock absorbers are double-action units, and a weight-saving hollow stabilizer bar helps neutralize body roll. In the front, the double wish-bone consists of unequal-length upper and lower A-arms. Most of the major components are squeeze-cast or forged from aluminum alloys that perform better than steel in these applications, in addition to saving weight. Such an extensive use of these alloys was made possible by the newly developed squeeze-casting process, which produces parts much stronger than would be possible employing conventional die-casting methods.
Weight distribution with driver and passenger is 50% front/50% rear, contributing to exceptional handling balance. Part of the credit goes to placement of the rotary engine behind the front axle, a front mid-engine design made possible only by the compact size of the rotary.
Extensive wind tunnel tests helped us give the RX-7 one of the lowest drag coefficients (Cd) in its class-0.29. Lower drag improves both performance and fuel efficiency, because less power is used to overcome air resistance. The effective aerodynamics also reduce wind noise. Attention to detail can be seen in such aerodynamic designs as the "double-bubble" roof contour. Although visually subtle, we found in the wind tunnel that it made a significant difference in the car's performance.
The P225/50R16 tires were developed specifically to meet the high-performance demands of the Mazda RX-7. The tires combine exceptional straight-line traction and cornering abilities. They're mounted on 16-inch wheels, eight inches wide and squeeze-cast of aluminum alloy. The design of the wheels not only saves unsprung weight, it also provides maximum cooling for the brakes. As with the tires, these wheels were developed especially for this car.
Low center of gravity, plus front and rear stabilizer bars, keeps body roll to a minimum. This improves both cornering performance and feel. Mazda engineers took full advantage of their opportunity to create a dedicated sports car suspension.
While the structure of the Mazda RX-7 is largely the result of the most advanced supercomputer designs, for inspiration we looked to nature. Spider webs and honeycombs. Or a bird's bone structure. Because these offer what we think a sports car should: light weight with exceptional strength. Only a lighter car can offer the pure sports car ideal: the responsiveness and control of a race car. Weight is weight, no matter how well-balanced. And only a strong structure can provide a stable platform for the suspension, withstand the constant jolts and indignities of road surfaces, and protect the occupants. And while an intense weight reduction program was a high priority in the development of the RX-7, weight was never shaved at the expense of structural integrity or strength. So, like a race car, the RX-7 is as strong and stable as it is fast. And it also proves that a car can be exciting to drive and still take good care of its occupants.
Active safety measures in a car are those design features that can help you avoid or escape potentially dangerous driving situations. One of the most important in the RX-7 is the computer-controlled Anti-lock Braking System (ABS). A sensor at each wheel detects any sudden change in wheel movement that could lead to lockup, and a microprocessor control momentarily relaxes braking pressure on that wheel so that it keeps rolling and maintains better traction. ABS not only can help you stop straighter in hard braking, it can help you keep steering control as well. This is particularly important in turns where, even when driving at relatively low speeds, locked wheels could cause a car to swing much wider than the road might allow. With ABS, you can more easily keep the car where it should be.
In addition to 3-point safety belts, an air bag Supplemental Restraint System (SRS) is standard for both the driver and passenger, complete with computerized "fail-safe" backup power circuitry. For the air bags to be fully effective, always fasten your 3-point safety belts properly. A rear-facing child restraint should never be used in this or any 2-seat vehicle with dual air bags. See the specifications page for details.
Many of the RX-7's structural details are directly related to passenger protection. These include passenger cell reinforcement (A),side intrusion beam (B), the "space-monocoque" structure itself (C), and the rear structural support beam (D). Supercomputer simulations helped us determine such variables as size, strength, and location. (Highlighting colors are for photographic clarity.)
No operational part of a car functions in isolation. The best suspension design won't be able to do its job if it isn't attached to a rigid and effective structure. It's the balance and cohesiveness of the RX-7's total design that makes it so exhilarating on the road.
Powerful as the supercomputers are, computer modeling at Mazda never substitutes for real-life road testing. But it ensures that the cars that reach the test track are viable prototypes, so that our drivers can concentrate on fine tuning. We then use the computer to incorporate the drivers' feed-back into each design stage. But ultimately, it's only Kansei Engineering, taking people into account, that makes the car feel just right. And that gives the RX-7 its full measure of true race car excitement.
Computer modeling techniques include the latest GNC (Geometric Modeling and Numerical Control) and DMA (Dynamic Modal Analysis) methods. With the supercomputer, we can build a very precise model of the car on the screen, then apply simulations of dynamic forces to generate precise analyses of how the various parts of the car will behave. Our engineers can then perform myriad "what-if" scenarios to arrive at the best possible design, something that would simply not be possible without the power of the computer.
Were you to guess the Mazda RX-7 rotary engine's physical dimensions and mechanical complexity solely from its smooth, free-revving power delivery, you'd probably visualize something quite large and heavy, maybe something with 12 cylinders and multiple banks of camshafts.
This unique engine, however, defies all normal expectations. Compact and light, the basic design has only three moving parts. Yet in the RX-7 the rotary delivers a prodigious amount of power for its size and weight: 255 horsepower at 6500 rpm, and 217 lb-ft of torque at 5000 rpm.
With ports instead of valves, the rotary is also an ideal candidate for turbocharging. And Mazda engineers took full advantage of the engine's characteristics, designing a sequential twin turbocharging system that works over the whole rpm range. Were you to guess the Mazda RX-7 rotary engine's physical dimensions and mechanical complexity solely from its smooth, free-revving power delivery, you'd probably visualize something quite large and heavy, maybe something with 12 cylinders and multiple banks of camshafts.
The Mazda sequential twin turbocharging arrangement is even more effective because the rotary has a natural super-charging effect in normal operation. An intercooler further increases power by cooling the intake air so that the turbochargers can force more of it into the rotor chambers. To ensure reliability, the whole design has undergone torturous testing, including simulated continuous acceleration runs 24 hours a day for three months.
The sequential operation of the RX-7's twin turbocharging system offers the best of both turbo worlds, lag-free at low rpm, yet with the high boost of a large capacity unit. The design is more sophisticated than traditional twin turbos to ensure a smoother transition from single to dual operation modes.
At low rpm, the full force of the exhaust gas is directed to only the primary turbocharger, giving the RX-7 nearly instant throttle response. As rpm increases, a "pre-spin" valve opens to start the secondary turbocharger spinning. It does not yet supply any boost, but when it does come on line, it will already be up to speed. At high rpm, the secondary turbo becomes fully operational. Transition to full operation is seamless, with no flat spot in the power curve.
The Torsen limited-slip differential helps put the RX-7's power to the ground. A limited-slip design has two primary functions. The first is torque management, transferring torque to the driving wheel with the better traction. The second function is allowing each driving wheel to respond individually to rpm differences dictated by vehicle direction and tire-to-road adhesion. The Torsen design is unique in allowing these two functions to occur simultaneously. Widely used in race cars, the Torsen unit is up to twice as effective, depending on conditions, as a conventional limited-slip design. And it improves control by transferring torque in a much more linear fashion.
The basic design of the rotary has only three moving parts: two rotors and a crankshaft. There are no valves, no cams, no lifters. A reciprocating engine expends much of its power potential in converting the linear motion of its pistons to the rotational motion of the crankshaft and in overcoming the friction of many moving parts. But the rotary engine generates rotational motion from the start. It revs freely and produces an extraordinarily smooth flow of power.
A pair of powerful 8-bit digital microprocessors govern every aspect of the engine's operation. The Bosch D-Jetronic fuel injection gives especially precise and quick fuel management, and fuzzy logic, an advanced computer artificial intelligence technology, automatically adjusts the idle speed to the load conditions. To help the engine breathe, there's an especially efficient induction system. At the other end, a large-capacity exhaust system incorporates a low-flow-resistance catalytic converter to reduce back pressure. The result: an extremely smooth engine with none of the temperamental behavior often associated with high-performance powerplants.
The intercooler for the turbo-charging system is located in the nose, to get the full benefit of a direct air stream. An oil cooler (two in the R-2) has its own intake duct.
The 5-speed gearbox offers a high-torque-capacity double-synchro mechanism in the three lower gears. The refined linkage provides short throws with a very positive feel, for quick, precise, and smooth shifts. An advanced 4-speed automatic transmission is also available.
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