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The Subaru EJ257 engine has become a popular choice among performance enthusiasts looking to achieve impressive horsepower figures. With the right modifications, this engine can be built to exceed 700 horsepower, making it a formidable option for both street and track applications. In this article, we will explore the ultimate EJ257 build, focusing on forged internals and high-flow fuel systems.
Understanding the EJ257 Engine
The EJ257 is a turbocharged flat-four engine that powers various Subaru models, including the WRX and STI. Known for its durability and potential for tuning, the EJ257 is a favorite among car enthusiasts. However, to push the engine beyond its factory limits, specific upgrades are necessary.
Forged Internals: The Foundation of Power
When building an engine for high horsepower, the choice of internals is crucial. Forged components provide the strength and reliability needed to handle increased power and boost levels. Here are the key components to consider:
- Forged Pistons: These are designed to withstand high temperatures and pressures, preventing failure under extreme conditions.
- Forged Connecting Rods: Stronger than factory rods, forged connecting rods can handle the increased stress of a high-performance build.
- Forged Crankshaft: A forged crankshaft provides enhanced durability and is essential for high horsepower applications.
Piston Selection
Choosing the right pistons is vital for achieving the desired compression ratio and performance. Look for pistons that are lightweight yet durable, with a design that promotes efficient combustion.
Connecting Rod Considerations
When selecting connecting rods, consider their weight, strength, and compatibility with your build. Brands that specialize in performance components often offer rods specifically designed for the EJ257.
High-Flow Fuel Systems: Fueling the Power
To support a high horsepower build, an efficient fuel system is essential. Upgrading to a high-flow fuel system ensures that your engine receives the necessary fuel to match the increased air intake from a larger turbocharger.
- Fuel Pump: Upgrading to a high-flow fuel pump is critical. Look for pumps that can deliver the required volume and pressure for your horsepower goals.
- Fuel Injectors: Larger fuel injectors will provide the necessary fuel volume. Choose injectors that are compatible with your engine management system.
- Fuel Lines: Upgrading to larger fuel lines can help reduce restrictions and ensure a steady flow of fuel to the engine.
Choosing the Right Fuel Pump
When selecting a fuel pump, consider the flow rate and pressure requirements for your target horsepower. Popular options for the EJ257 include aftermarket pumps that can support over 700 hp.
Injector Sizing
Injector sizing is crucial for maintaining the correct air-fuel ratio. Calculate the required injector size based on your horsepower goals and ensure they are compatible with your fuel system.
Turbocharger Selection
A high-performance turbocharger is essential for achieving 700+ horsepower. The right turbo will provide the necessary boost while maintaining responsiveness. Consider the following factors:
- Turbo Size: Choose a turbo that can deliver the required airflow for your horsepower goals. Larger turbos typically provide more power but may have a lag.
- Compressor and Turbine Design: Look for designs that optimize efficiency and reduce spool time.
- Wastegate Setup: An external wastegate can provide better boost control and prevent boost creep.
Popular Turbo Options
Some popular turbo options for the EJ257 include the Garrett GT series and the Precision Turbo offerings, both of which are known for their performance and reliability.
Engine Management Systems
To maximize the potential of your EJ257 build, an effective engine management system is crucial. A standalone ECU or a reflash of the factory ECU can help manage fuel delivery, ignition timing, and boost levels.
- Standalone ECUs: These systems offer the most flexibility and tuning options for high-performance builds.
- Reflashed ECUs: A reflash can be a cost-effective option for those looking to increase performance without a complete overhaul.
Choosing the Right Tuning Software
Select tuning software that is compatible with your engine management system. Popular options include Cobb Tuning and AEM, both of which offer comprehensive tuning solutions for the EJ257.
Cooling Solutions
High horsepower builds generate significant heat, making effective cooling solutions essential. Upgrading your cooling system can help maintain optimal engine temperatures.
- Intercooler: A high-performance intercooler will help reduce intake temperatures, improving performance and reliability.
- Radiator: Upgrading to a larger radiator can enhance cooling efficiency, especially during high-performance driving.
Intercooler Options
Consider options like front-mount intercoolers (FMIC) for maximum cooling efficiency. Brands like Mishimoto and ETS offer quality intercoolers that fit the EJ257.
Conclusion
Building an EJ257 for 700+ horsepower is an ambitious but rewarding project. By focusing on forged internals, a high-flow fuel system, and proper engine management, you can create a powerful and reliable engine. With the right components and tuning, your EJ257 can deliver the performance you desire on the street or the track.