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The Mazda RX-7 is a beloved sports car known for its lightweight chassis and rotary engine. However, many enthusiasts are opting for an LS swap to enhance performance. Boosting an LS-driven RX-7 to 550 horsepower requires careful consideration of supporting modifications. This article outlines essential upgrades to achieve that power level while maintaining reliability.
Understanding the LS Swap
The LS engine, a V8 powerhouse from General Motors, offers a significant performance boost compared to the original rotary engine. When swapping an LS into an RX-7, it’s crucial to understand the compatibility and the modifications needed to support the increased power.
Essential Supporting Mods
To achieve 550 horsepower in an LS-driven RX-7, several supporting modifications are necessary. These enhancements will ensure the engine runs efficiently and reliably under high power conditions.
- Upgraded Fuel System: A high-flow fuel pump and larger injectors are essential to meet the increased fuel demands.
- Performance Exhaust: A free-flowing exhaust system reduces back pressure and enhances power output.
- Cold Air Intake: A high-performance intake allows for better airflow into the engine, improving combustion efficiency.
- ECU Tuning: A proper tune is necessary to optimize fuel maps and ignition timing for the new setup.
- Upgraded Cooling System: A more efficient radiator and cooling fans help manage the increased heat generated by the engine.
- Stronger Transmission: Upgrading to a robust transmission ensures it can handle the torque produced by the LS engine.
- Suspension Upgrades: Enhanced suspension components improve handling and stability at higher speeds.
- Wheels and Tires: Properly sized wheels and high-performance tires provide the necessary grip for the increased power.
Upgrading the Fuel System
A critical aspect of boosting an LS-driven RX-7 is ensuring the fuel system can deliver adequate fuel to the engine. Upgrading the fuel pump and injectors is vital for achieving the desired horsepower.
Fuel Pump
Consider installing a high-performance fuel pump capable of supporting the flow requirements of 550 horsepower. Popular options include the AEM 50-1200 or the Walbro 450, both known for their reliability and performance.
Fuel Injectors
Upgrading to larger fuel injectors ensures that the engine receives enough fuel. Look for injectors rated for at least 80 lb/hr to support the increased power demands.
Performance Exhaust System
A performance exhaust system is essential for reducing back pressure and improving exhaust flow. This modification not only enhances power but also improves the engine’s sound.
Exhaust Headers
Investing in long-tube headers can significantly improve exhaust flow. Brands like Hooker and Kooks offer high-quality options designed for the LS engine.
Cat-Back Exhaust
A cat-back exhaust system will further enhance performance by allowing exhaust gases to exit more freely. Look for systems that offer a balance of sound and performance.
Cold Air Intake System
A cold air intake system helps the engine breathe better by providing cooler, denser air. This modification is relatively easy to install and can yield noticeable performance gains.
ECU Tuning
After completing the supporting mods, a professional ECU tune is necessary to optimize the engine’s performance. This step ensures that the fuel maps and ignition timing are adjusted for maximum efficiency and power.
Upgraded Cooling System
With increased horsepower comes increased heat. Upgrading the cooling system is crucial to prevent overheating and ensure the engine operates within safe temperature ranges.
Radiator Upgrade
Consider installing a larger, more efficient radiator to improve heat dissipation. Aftermarket options from companies like Mishimoto or DeWitts provide excellent cooling performance.
Cooling Fans
Upgrading to high-performance electric fans can enhance airflow through the radiator, further improving cooling efficiency.
Strong Transmission
To handle the power output of a 550 horsepower LS engine, upgrading the transmission is essential. A stock transmission may not withstand the increased torque, leading to premature failure.
Transmission Options
Consider upgrading to a T56 six-speed manual transmission or a 4L80E automatic transmission for better durability and performance. Both options are popular among LS swap enthusiasts.
Suspension Upgrades
To effectively manage the increased power and improve handling, upgrading the suspension is crucial. A well-balanced suspension setup enhances stability and cornering performance.
Coilovers
Installing adjustable coilovers allows for fine-tuning of ride height and damping settings, providing a more responsive and comfortable driving experience.
Sway Bars
Upgrading to performance sway bars reduces body roll during cornering, improving overall handling dynamics.
Wheels and Tires
Properly sized wheels and high-performance tires are essential for transferring the increased power to the ground. Selecting the right combination will enhance traction and handling.
Wheel Size
Consider wheels that are at least 18 inches in diameter to accommodate larger brakes and provide better handling characteristics.
Tire Selection
Invest in high-performance tires that offer excellent grip and stability. Brands like Michelin and Nitto provide options designed for high horsepower applications.
Conclusion
Boosting an LS-driven RX-7 to 550 horsepower is an exciting project that requires careful planning and execution. By investing in the right supporting modifications, you can achieve impressive performance while maintaining reliability. With the proper upgrades, your RX-7 will be a thrilling machine on both the street and the track.