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The Mazda RX-7 is a legendary sports car known for its lightweight design and exceptional handling. However, many enthusiasts have sought to enhance its performance further by swapping in a powerful LS engine. This guide will walk you through the process of building a 600+ HP Mazda RX-7 LS swap, ensuring you have all the information needed to tackle this ambitious project.
Understanding the LS Swap
An LS swap involves replacing the RX-7’s original rotary engine with a V8 LS engine from General Motors. This swap offers numerous benefits, including increased horsepower, better torque delivery, and improved reliability. Below are some key points to consider:
- Weight distribution: The LS engine is heavier, affecting the car’s balance.
- Compatibility: Ensure your RX-7 can accommodate the LS engine dimensions.
- Wiring and electronics: Be prepared to handle complex wiring for the swap.
Choosing the Right LS Engine
When selecting an LS engine for your RX-7, consider the following options:
- LS1: A great starting point with solid power and torque.
- LS3: Offers more horsepower and is a popular choice for swaps.
- LS7: The most powerful option, providing over 500 HP naturally aspirated.
Essential Parts and Tools
Gathering the right parts and tools is crucial for a successful LS swap. Here’s a list of essential items you’ll need:
- LS engine and transmission
- Engine mounts
- Transmission adapter plate
- Wiring harness
- Exhaust headers
- Cooling system components
- Fuel system upgrades
- Tools: socket set, wrenches, engine hoist, and more
Step-by-Step Swap Process
1. Preparation
Before starting the swap, ensure you have a clean workspace and all necessary tools and parts. Begin by removing the original rotary engine from the RX-7. This process typically involves:
- Disconnecting the battery and removing electrical connections.
- Draining fluids from the engine and transmission.
- Removing the intake and exhaust systems.
- Unbolting the engine from the mounts and lifting it out.
2. Installing Engine Mounts
Once the original engine is out, install the new engine mounts designed for the LS swap. These mounts ensure proper alignment and fitment of the LS engine in the RX-7 chassis.
3. Fitting the LS Engine
Carefully lower the LS engine into the engine bay, aligning it with the newly installed mounts. Make sure to check for clearance issues, especially around the firewall and suspension components.
4. Connecting the Transmission
Attach the transmission to the LS engine using the appropriate adapter plate. Ensure all bolts are tightened to manufacturer specifications to avoid any issues during operation.
5. Wiring and Electronics
Wiring can be one of the most challenging aspects of an LS swap. Use a standalone wiring harness or modify the existing RX-7 harness to connect the LS engine’s electronic components. Pay special attention to:
- ECU placement and connections
- Sensor wiring
- Fuel pump and ignition system integration
6. Upgrading the Fuel System
The LS engine requires a higher fuel delivery rate than the original rotary engine. Upgrade the fuel system by installing a new fuel pump, larger fuel lines, and high-flow injectors to support the increased power demands.
7. Exhaust System Installation
Install the exhaust headers and connect them to a custom exhaust system. Ensure that the exhaust routing does not interfere with any components and meets local noise regulations.
8. Cooling System Setup
With the additional power from the LS engine, an upgraded cooling system is necessary. Install a larger radiator, new hoses, and ensure the cooling fans are adequate to keep the engine temperature in check.
9. Final Checks and Testing
Once everything is installed, double-check all connections, bolts, and fluid levels. Start the engine and monitor for any leaks or issues. Take the RX-7 for a test drive to ensure everything is functioning properly.
Conclusion
Building a 600+ HP Mazda RX-7 LS swap is a challenging but rewarding project. With careful planning and attention to detail, you can transform your RX-7 into a powerful machine that delivers exhilarating performance. Remember to take your time, seek help when needed, and enjoy the process of creating a unique and powerful vehicle.