Table of Contents
The Subaru WRX has long been a favorite among car enthusiasts for its impressive performance and rally heritage. In recent years, many enthusiasts have turned to E85 fuel for its benefits in high-performance applications. This article will explore the process of building a 600+ horsepower WRX with an E85 conversion, focusing on high-performance parts and tuning strategies.
Understanding E85 Fuel
E85 is a blend of 85% ethanol and 15% gasoline. This fuel offers several advantages for performance tuning:
- Higher Octane Rating: E85 typically has an octane rating of around 100-105, allowing for more aggressive tuning.
- Cooler Combustion Temperatures: Ethanol has a higher latent heat of vaporization, which helps keep engine temperatures lower.
- Increased Power Potential: The ability to run more boost and timing can lead to significant power gains.
Essential High-Performance Parts
To achieve over 600 horsepower, several key components must be upgraded. Below are the essential parts for a successful E85 conversion:
- Fuel System Upgrades: A high-flow fuel pump and larger fuel injectors are crucial for delivering the increased fuel requirements of E85.
- Turbocharger: Upgrading to a larger turbocharger will provide the airflow necessary for high power levels.
- Intercooler: A larger front-mount intercooler will help reduce intake temperatures, improving performance and reliability.
- Exhaust System: A high-flow exhaust system will reduce back pressure and improve turbo efficiency.
- Engine Internals: Forged pistons and rods should be considered for reliability at high power levels.
Upgrading the Fuel System
When converting to E85, the fuel system is one of the first areas that require attention. Here are the primary components to focus on:
- Fuel Pump: Upgrade to a high-flow fuel pump capable of supporting the required horsepower.
- Fuel Injectors: Larger injectors (typically 1000cc or larger) are necessary to handle the increased fuel demand.
- Fuel Lines: Ensure that fuel lines can handle the corrosive nature of ethanol.
Choosing the Right Turbocharger
The turbocharger is a key component in achieving high horsepower. Selecting the right turbo involves understanding your performance goals:
- Turbo Size: A larger turbo will generally support higher horsepower but may introduce turbo lag.
- Turbo Type: Consider a twin-scroll turbo for better response and efficiency.
- Supporting Mods: Ensure that other supporting modifications (like the exhaust and intercooler) are in place to maximize turbo performance.
Improving Cooling with an Intercooler
A larger intercooler is essential for maintaining optimal intake temperatures, especially when running higher boost levels. Consider the following:
- Core Size: A larger core will provide better cooling but may require modification to the front end of the vehicle.
- Material: Look for aluminum intercoolers for better heat dissipation.
- Placement: Ensure proper placement for maximum airflow.
Exhaust System Enhancements
A high-flow exhaust system is vital for reducing back pressure and enhancing turbo efficiency. Key considerations include:
- Downpipe: A larger diameter downpipe will help improve turbo spool and reduce exhaust temperatures.
- Cat-back System: A cat-back exhaust system should be chosen for optimal flow and sound.
- Material: Stainless steel is preferred for durability and resistance to corrosion.
Strengthening Engine Internals
To handle the increased power and boost levels, upgrading the engine internals is critical. Consider the following components:
- Pistons: Forged pistons are recommended for their strength and durability at high power levels.
- Rods: Upgrading to forged connecting rods will ensure reliability under stress.
- Head Gasket: A stronger head gasket can prevent failures under increased boost.
Tuning Strategies for E85
Once all the high-performance parts are installed, proper tuning is essential to maximize performance and reliability. Here are some strategies:
- ECU Tuning: A professional tune is necessary to optimize fuel maps and ignition timing for E85.
- Wideband O2 Sensors: Installing wideband O2 sensors will help monitor air-fuel ratios accurately.
- Data Logging: Regular data logging will help track performance and identify any issues.
Conclusion
Building a 600+ horsepower WRX with an E85 conversion requires careful planning and the right high-performance parts. By upgrading the fuel system, turbocharger, intercooler, exhaust system, and engine internals, and by implementing proper tuning strategies, you can achieve impressive power levels while enjoying the benefits of E85 fuel. With dedication and the right approach, your WRX can become a formidable performance machine.