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The Mazda RX-7 has long been celebrated for its lightweight design and rotary engine, making it a favorite among car enthusiasts. In this article, we will explore how a modified FD RX-7 achieved an impressive 420 wheel horsepower (WHP) using E85 fuel. This case study highlights the tuning process, modifications made, and the performance results that can be obtained with the right setup.
Understanding the FD RX-7
The FD RX-7, produced between 1992 and 2002, is renowned for its unique rotary engine, lightweight chassis, and exceptional handling. The 13B rotary engine is compact and offers a high power-to-weight ratio, making it a prime candidate for tuning and performance upgrades.
The Benefits of E85 Fuel
E85 fuel, a blend of 85% ethanol and 15% gasoline, has gained popularity in the automotive world for several reasons:
- Higher octane rating: E85 typically has a higher octane rating than regular gasoline, allowing for more aggressive tuning.
- Cooling properties: Ethanol has a cooling effect during combustion, which can reduce the risk of knock.
- Environmental benefits: E85 is considered a renewable fuel, making it a greener option compared to traditional fuels.
Modifications for Maximum Performance
To reach the 420 WHP mark on E85, several key modifications were made to the FD RX-7. Each component played a crucial role in enhancing performance and reliability.
- Upgraded Turbocharger: A larger turbocharger was installed to increase airflow and boost pressure.
- Intercooler Upgrade: A high-performance intercooler was added to reduce intake temperatures, improving engine efficiency.
- Fuel System Enhancements: Upgraded fuel injectors and a high-flow fuel pump were necessary to accommodate the increased fuel demands of E85.
- Tuning Software: A custom tuning solution was implemented to optimize the engine’s performance parameters for E85 fuel.
The Tuning Process
The tuning process is critical to achieving optimal performance. Here’s how the tuning was executed for the FD RX-7:
- Baseline Dyno Run: The car underwent a baseline dyno run to establish initial performance metrics before modifications.
- Adjusting Fuel Maps: The fuel maps were adjusted to ensure proper air-fuel ratios for E85 operation.
- Boost Control Settings: Boost levels were carefully calibrated to maximize power without risking engine damage.
- Final Dyno Tuning: After all adjustments, a final dyno run confirmed the car’s output of 420 WHP.
Performance Results
After completing the modifications and tuning, the FD RX-7 showcased remarkable performance results:
- Power Output: The car achieved a peak output of 420 WHP.
- Torque Figures: Torque was also significantly increased, providing better acceleration and responsiveness.
- Track Performance: The RX-7 demonstrated improved lap times and overall handling characteristics on the track.
Conclusion
The journey to achieving 420 WHP on E85 fuel in an FD RX-7 illustrates the potential of rotary engines when paired with the right modifications and tuning. With its lightweight design and the benefits of E85, the RX-7 remains a formidable contender in the world of performance cars. Enthusiasts looking to push the limits of their vehicles can take inspiration from this build and explore the possibilities that lie within their own projects.