Mazda RX-7: A Rotary Revolution

The Enduring Allure of the Mazda RX-7: A Rotary Masterpiece

In the pantheon of Japanese sports cars, few names evoke as much passion and intrigue as the Mazda RX-7. Revered by enthusiasts and often misunderstood by the uninitiated, the RX-7 is inextricably linked to its groundbreaking rotary engine. This unique powerplant, developed by Felix Wankel and championed by Mazda, set the RX-7 apart from its contemporaries, offering a distinct driving experience that continues to captivate car lovers decades later. This article delves into the rich history of all three generations of the RX-7, exploring their evolution, triumphs, and the enduring legacy of rotary power.

The Heart of the Matter: Understanding the Rotary Engine

At the core of the RX-7's identity lies its rotary, or Wankel, engine. Unlike conventional internal combustion engines that rely on pistons moving up and down in cylinders, the rotary engine uses a triangular rotor that spins eccentrically within an epitrochoidal housing. This fundamental difference leads to several key characteristics:

• Smoother Operation: The absence of reciprocating mass means rotary engines are inherently smoother and vibrate less than piston engines.
• Higher Power-to-Weight Ratio: Rotary engines can produce more power from a smaller displacement, making them ideal for compact, lightweight sports cars.
• Compact Design: The rotary engine's smaller physical size and fewer moving parts contribute to a more compact overall vehicle design.

However, this innovative technology also presents challenges. Rotary engines are known for their higher fuel consumption and the necessity of burning oil to lubricate the apex seals, which are critical for maintaining compression. This has historically led to a reputation for being less reliable and requiring more frequent and specialised maintenance. Despite these hurdles, Mazda's unwavering commitment to the rotary engine is a testament to its belief in its potential.

Generation 1: The SA22C/FB (1978-1985) - The Genesis

The RX-7's journey began in 1978, building upon Mazda's decades of rotary engine development. Under the leadership of Kenichi Yamamoto, Mazda refined the 12A rotary engine, enhancing its fuel economy and improving the durability of its apex seals. The result was an engine worthy of a dedicated sports car, and Mazda's engineers rose to the challenge, crafting the perfect chassis for this unique powerplant. The outcome was the lightweight, two-door coupe that would become the first-generation RX-7, codenamed SA22C, or FB for later iterations.

Series 1 (1978-1980): Launched with a 1.1-liter 12A engine, the Series 1 RX-7 tipped the scales at under 1100kg. It offered a respectable top speed of 115mph and a 0-60mph time of just 9.5 seconds – impressive figures for its small engine capacity at the time. In Japan, its engine displacement helped buyers avoid higher taxes on larger-engined vehicles, boosting sales.

The SA22C's handling was another major selling point. Its featherweight construction, 50:50 weight distribution, and multi-link live axle suspension gave it a lively and engaging character that resonated with drivers.

Series 2 (1981-1983): The Series 2 introduced subtle styling revisions, a standard five-speed manual gearbox (with optional automatics), and a shorter gearstick. The GSL trim level gained a rear LSD and all-round disc brakes.

Series 3 (1984-1985): The final iteration of the Mk1 saw the introduction of the more powerful 13B engine (1.3-litre) in American markets, boosting output to 135hp. Japanese Domestic Market (JDM) versions also received a turbocharged 12A option, providing a more potent experience for domestic buyers.

Motorsport Pedigree

The first-generation RX-7 wasn't just a success on the road; it also made its mark in motorsport. It clinched the 1980 and 1981 British Saloon Car Championship titles and achieved a notable victory at the 24 Hours of Spa, silencing critics who doubted the rotary engine's reliability.

By most accounts, the Mk1 RX-7 was a triumph, with Mazda selling an impressive 470,000 units worldwide. It remains the best-selling rotary-powered car in history, a testament to its innovative design and widespread appeal.

Generation 2: The FC (1985-1992) - The Grand Tourer

Following the success of the original RX-7, Mazda took a different direction with its successor, the FC. While retaining the rotary engine and the two-door coupe silhouette, the Mk2 RX-7 shifted its focus from pure sports car to a more comfortable grand tourer, designed for longer distances rather than sharp, twisty roads.

The American Influence

Mazda's primary objective with the FC was to appeal to the American market. Market research indicated a preference for a softer, more powerful coupe. To achieve this, significant changes were made to the FC's underpinnings.

The playful oversteer of the SA22C was replaced with a greater emphasis on stability. Mazda swapped the live rear axle for an independent suspension system and introduced the innovative Dynamic Tracking Suspension System (DTSS). DTSS subtly adjusted the toe angle of the rear wheels during cornering, enhancing stability and predictability. Additionally, the Auto Adjusting Suspension (AAS) system adapted the dampers to road conditions, further improving ride comfort. While these advancements enhanced the car's touring credentials, some keen drivers felt they dulled steering feedback.

Rotary Evolution

The FC's engine saw significant development. The 13B engine, previously an option in the US-market Mk1, became standard across all markets. Initially, it featured new variable intake technology. In 1986, a turbocharged variant emerged, boosting power to around 180hp. By 1989, revisions to the twin-scroll turbo and compression ratio pushed the FC's output to 200hp, a considerable leap from the Mk1.

Despite the increased power, Mazda managed to keep the weight down to around 1200kg. This, combined with the enhanced engine, resulted in a 0-60mph time of just 6.7 seconds and a top speed approaching 150mph. A convertible version was also introduced, adding a touch of luxury.

FC RX-7: Pros and Cons

Pros:

• Characterful rotary engine
• Good balance of handling and comfort
• Available as a convertible

Cons:

• Rotary engine maintenance requirements
• Interior materials could be better
• Potential for rust issues

Common FC RX-7 Problems:

• Apex seal failure
• Electrical gremlins
• Rear differential wear

Generation 3: The FD (1992-2002) - The Pinnacle of Rotary Performance

Despite Mazda's efforts to cater to their target audience with the FC, sales were roughly half that of the original RX-7. For the third and final generation, Mazda decided to revert to the RX-7's performance-oriented roots, ditching the grand tourer persona in favour of outright agility and power. The FD, debuting in 1992, pushed the boundaries of performance even further than the original SA22C.

A Striking Evolution in Design and Dynamics

The boxy, Porsche 924-inspired styling of the FC made way for the FD's svelte, curvaceous design, which stood out dramatically against its more subdued rivals. This sleek new aesthetic was matched by significant mechanical advancements. While retaining the sophisticated independent rear suspension, the overall setup was honed for a more rewarding driving experience. The ride was firmer, but not uncomfortably so, and the steering offered more weight and feedback, making the FD a far more communicative car than its predecessor.

Twin-Turbo Power and Weight Advantage

With the horsepower wars of the nineties in full swing, the FC's engine simply wasn't competitive against rivals like the Nissan 300ZX (280hp) and the Toyota Supra Mk4 (320hp). Mazda responded by introducing a revolutionary sequential twin-turbocharger system. This innovative setup used a smaller turbo for low-end response, with a larger turbo kicking in at higher RPMs for an extra surge of power. The result was a peak power output of 236hp in export models, and 250hp in Japan.

While still not matching the raw horsepower figures of some competitors, the RX-7's trump card was its weight. The Supra weighed around 1500kg and the 300ZX similar, while the FD tipped the scales at approximately 1250kg. This significant weight advantage allowed the FD to achieve 60mph quicker than the Nissan and feel more agile on track.

The Price of Innovation

Despite its impressive performance and stunning looks, the FD RX-7 suffered from ambitious pricing upon its release, positioning it in direct competition with established European luxury sports cars. Although Mazda later reduced the price, the initial misstep had already impacted sales. The FD continued to be sold in the UK until 1998 but bowed out of the rest of Europe much earlier. Production eventually transitioned to a Japan-only model, with the final Series 8 cars produced between 1998 and 2002, making them highly sought-after imports in Western markets.

The FD RX-7 is widely considered the ultimate expression of the RX-7's potential and a benchmark for rotary engine performance.

FD RX-7: Pros and Cons

Pros:

• Exceptional handling due to 50:50 weight balance
• Phenomenal engine performance (when properly maintained)
• Timeless, captivating design

Cons:

• Requires constant, meticulous maintenance
• Expensive ownership
• Small cabin and boot space
• Can feel twitchy at low speeds

Common FD RX-7 Problems:

• Apex seal failure (again, the Achilles' heel)
• Suspension sag
• Lack of diligent oil maintenance

The Mazda Model R Transmission Swap: A Different Kind of RX-7 Connection

While not directly about the RX-7's rotary engine, the information regarding the Mazda Model R transmission highlights the versatility and shared components within Mazda's engineering. The Model R transmission, found in both RX-7s and B2600 trucks, is noted for its robustness and ability to handle high RPMs and significant horsepower. This makes it a popular choice for swaps into other vehicles, such as the Mitsubishi Starion. The detailed explanation of adapting this transmission involves careful consideration of bellhousings, shifter positions, clutch components, and driveshafts, showcasing the intricate nature of automotive engineering and customisation.

Conclusion: A Legacy of Innovation

The Mazda RX-7 is more than just a car; it's a statement. It represents a bold commitment to an unconventional engine technology, pushing the boundaries of performance and design. From the agile first generation to the refined second, and culminating in the exhilarating third, the RX-7 has left an indelible mark on automotive history. While the rotary engine demands a dedicated owner, its unique character and thrilling performance ensure that the RX-7 will continue to be celebrated and sought after by enthusiasts for generations to come. Whether you admire its engineering, its driving dynamics, or its iconic status, the Mazda RX-7 stands as a true testament to automotive passion and innovation.

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