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The Subaru EJ255 engine is known for its robust performance and tuning potential. To maximize its capabilities, many enthusiasts turn to supporting modifications that enhance power delivery and efficiency. Two popular upgrades are the ATI underdrive pulleys and the AEM boost controller. This article explores these modifications and how they can significantly improve the performance of your EJ255.
Understanding the EJ255 Engine
The EJ255 is a turbocharged flat-four engine that powers several Subaru models. It is known for its balance of power and reliability, making it a favorite among tuners. However, to unlock its full potential, supporting modifications are essential.
ATI Underdrive Pulleys
Underdrive pulleys are designed to reduce the rotational mass on the engine, allowing it to rev more freely and produce more power. The ATI underdrive pulleys specifically offer significant benefits for the EJ255.
Benefits of ATI Underdrive Pulleys
Switching to ATI underdrive pulleys can lead to several advantages:
- Increased Horsepower: By reducing the load on the engine accessories, more power is directed to the wheels.
- Improved Throttle Response: Lighter pulleys allow the engine to rev quicker, enhancing driving dynamics.
- Better Fuel Efficiency: Less energy wasted on accessories can lead to improved fuel economy.
Installation Considerations
Installing ATI underdrive pulleys requires some mechanical knowledge. Here are the key steps:
- Gather Tools: Ensure you have the necessary tools, including a socket set, torque wrench, and a crank pulley tool.
- Remove Stock Pulleys: Carefully remove the stock pulleys while following the manufacturer’s guidelines.
- Install New Pulleys: Install the ATI pulleys and torque them to the specified settings.
AEM Boost Controller
The AEM boost controller is another critical component for enhancing the performance of the EJ255. This device allows for precise control over boost levels, enabling better tuning and performance optimization.
Advantages of the AEM Boost Controller
Using an AEM boost controller offers numerous benefits:
- Custom Boost Settings: Adjust boost levels to match your tuning goals and driving style.
- Improved Engine Performance: Fine-tuning boost can lead to significant performance gains.
- Data Logging Capabilities: Monitor performance metrics for better tuning decisions.
Installation Steps for AEM Boost Controller
Installing the AEM boost controller involves several steps:
- Disconnect Battery: Ensure safety by disconnecting the battery before installation.
- Mount the Controller: Find a suitable location for the boost controller inside the vehicle.
- Wiring: Follow the wiring diagram provided in the manual to connect the controller to the ECU and boost source.
Combining Mods for Maximum Effect
When used together, the ATI underdrive pulleys and AEM boost controller create a synergistic effect, enhancing the overall performance of the EJ255. This combination allows for better throttle response, increased horsepower, and more efficient boost management.
Tuning Tips
After installing these mods, consider the following tuning tips:
- Start Conservatively: Begin with lower boost settings and gradually increase as you monitor performance.
- Use a Wideband O2 Sensor: This will help you keep track of air-fuel ratios during tuning.
- Consult Professionals: If unsure, seek advice from tuning professionals to optimize your setup.
Conclusion
Upgrading to ATI underdrive pulleys and an AEM boost controller can significantly enhance the performance of your Subaru EJ255 engine. These supporting modifications not only improve horsepower and throttle response but also contribute to a more enjoyable driving experience. Whether you’re a seasoned tuner or a newcomer, these upgrades are worth considering for unlocking the full potential of your EJ255.