Step-by-step Guide to Building a 400+ Hp Fa24 Wrx with Upgraded Intercooler and Exhaust

The FA24 WRX has become a popular choice for enthusiasts looking to build a high-performance vehicle. With the right modifications, achieving over 400 horsepower is possible. This guide will walk you through the essential steps to upgrade your WRX with an intercooler and exhaust system.

Understanding the FA24 Engine

The FA24 engine is a turbocharged 2.4-liter flat-four engine that offers a solid foundation for performance upgrades. Before diving into modifications, it’s crucial to understand its components and capabilities.

  • Engine Specifications
  • Stock Performance Metrics
  • Common Weak Points

Step 1: Upgrading the Intercooler

One of the first upgrades to consider is the intercooler. A larger, more efficient intercooler can help reduce intake air temperatures, leading to better performance.

Choosing the Right Intercooler

When selecting an intercooler, consider the following:

  • Core Size
  • Material Quality
  • Fitment and Installation

Installation Process

Follow these steps to install your new intercooler:

  • Remove the front bumper and factory intercooler.
  • Install the new intercooler using provided brackets and hardware.
  • Reconnect all piping and ensure there are no leaks.

Step 2: Upgrading the Exhaust System

A high-performance exhaust system is crucial for improving airflow and enhancing engine performance. Upgrading your exhaust will help you achieve that 400+ hp goal.

Selecting the Right Exhaust Components

Consider these factors when choosing an exhaust system:

  • Material (Stainless Steel vs. Mild Steel)
  • Diameter of Exhaust Piping
  • Type of Muffler (Straight-Through vs. Chambered)

Installation Steps

To install your upgraded exhaust system, follow these steps:

  • Lift the vehicle and secure it with jack stands.
  • Remove the old exhaust system starting from the downpipe.
  • Install the new exhaust components, ensuring proper alignment.

Step 3: Tuning the Engine

After making significant modifications, tuning is essential to maximize performance. A proper tune will ensure that your FA24 runs efficiently with the new upgrades.

Choosing a Tuner

Select a reputable tuner who specializes in Subaru vehicles. Look for:

  • Experience with FA24 Engines
  • Positive Reviews from Other Enthusiasts
  • Access to Dyno Tuning Facilities

Tuning Process

The tuning process typically involves:

  • Connecting the vehicle to a dynamometer.
  • Adjusting fuel maps and ignition timing.
  • Testing and fine-tuning for optimal performance.

Step 4: Supporting Modifications

To ensure your WRX handles the increased power effectively, consider additional modifications:

  • Upgraded Fuel System
  • High-Performance Turbocharger
  • Enhanced Suspension Components

Final Considerations

Building a 400+ hp FA24 WRX is an exciting project that requires careful planning and execution. By upgrading the intercooler, exhaust system, and tuning the engine, you can achieve impressive performance. Always remember to prioritize safety and reliability in your modifications.

Resources for Further Learning

  • Online Forums and Communities
  • Performance Parts Retailers
  • Automotive Performance Books