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The Subaru WRX STI is renowned for its performance and rally heritage. One of the most impactful upgrades you can make to enhance its power is upgrading the turbocharger. This article will explore how to elevate your WRX STI from factory power levels to over 400 horsepower using either the FP Red or BorgWarner EFR turbochargers.
Understanding Factory Turbocharger Limitations
The factory turbocharger on the WRX STI is designed to provide a balance between performance and reliability. While it delivers decent power, it often falls short for enthusiasts seeking higher horsepower. Factors such as turbo size, efficiency, and boost levels play a crucial role in performance, and upgrading to a larger, more efficient turbocharger can unlock significant power gains.
Choosing the Right Turbocharger
When considering a turbo upgrade, two popular options are the FP Red and BorgWarner EFR series. Each has its unique characteristics that cater to different performance goals.
FP Red Turbocharger
The FP Red turbocharger is a popular choice among WRX STI enthusiasts. Known for its ability to produce substantial power without sacrificing too much drivability, the FP Red can support power levels exceeding 400 horsepower.
- Great spool characteristics, providing power quickly.
- Compatible with stock and upgraded fuel systems.
- Durable construction for long-term reliability.
BorgWarner EFR Turbocharger
The BorgWarner EFR series is known for its advanced technology and efficiency. These turbochargers feature a dual ball bearing design and integrated wastegate, which contribute to quicker spool times and enhanced performance.
- Exceptional efficiency and power output.
- Lightweight design for improved responsiveness.
- Integrated features reduce installation complexity.
Installation Considerations
Upgrading your turbocharger requires careful planning and consideration. Here are some key points to keep in mind during the installation process:
- Ensure compatibility with your existing engine setup.
- Upgrade supporting modifications such as fuel injectors, intercooler, and exhaust.
- Consider tuning options to maximize performance and reliability.
Supporting Modifications
To fully realize the potential of your new turbocharger, supporting modifications are essential. Here are some recommended upgrades:
- Fuel System Upgrades: Upgrading your fuel injectors and fuel pump will ensure that your engine receives the necessary fuel to support higher horsepower.
- Intercooler: A larger intercooler will help keep intake temperatures down, improving performance and preventing knock.
- Exhaust System: A high-flow exhaust system will reduce back pressure and allow your turbo to perform more efficiently.
Tuning Your WRX STI
After installing your new turbocharger and supporting modifications, tuning is crucial. A proper tune will optimize air-fuel ratios and ignition timing, ensuring that your engine runs efficiently and reliably at higher power levels.
Choosing a Tuner
Selecting an experienced tuner familiar with the WRX STI platform is vital for achieving the best results. Look for tuners who have a proven track record with turbo upgrades and can provide data-driven results.
Conclusion
Upgrading your WRX STI’s turbocharger to either the FP Red or BorgWarner EFR can significantly enhance performance, pushing your vehicle beyond the 400 horsepower mark. With the right supporting modifications and a proper tune, you can enjoy a thrilling driving experience that showcases the true potential of your Subaru.