AEM Induction Cold Air Intake System

Fits 2019–2021 Subaru WRX STI 2.5L H4

Part #: 21-863C

Overview

The AEM 19-21 Subaru WRX STI 2.5L H4 Cold Air Intake System is engineered to enhance your vehicle’s airflow, supporting improved horsepower and torque. Designed for enthusiasts seeking both performance gains and reliable filtration, this intake system combines advanced materials and thoughtful design to optimize engine response and efficiency. Whether you're upgrading for increased power or improved throttle response, this intake offers a straightforward way to upgrade your Subaru’s intake system with confidence. This system is ideal for drivers who want to maximize their vehicle’s potential while maintaining durability and ease of maintenance. Its high-quality components are built to withstand the rigors of daily driving and spirited performance, making it a practical choice for both street and occasional track use.

Key Features

Designed to deliver superior airflow and filtration, the AEM intake system features a large, washable synthetic air filter that can go up to 100,000 miles between services under normal highway conditions. The mandrel-bent aluminum intake tube ensures smooth airflow, reducing turbulence and enhancing engine efficiency. A custom heat shield helps protect intake air from engine bay heat, ensuring cooler, denser air enters the engine for optimal combustion. The system includes all necessary hardware for a straightforward installation, making it accessible for DIY enthusiasts and professional installers alike.

• Oversized, conical synthetic washable air filter for long service intervals
• Mandrel-bent aluminum intake tube for smooth airflow
• High-quality hardware for easy installation
• Custom heat shield to protect intake air from engine bay heat
• Supports increased horsepower and torque
• Designed for durability and reliable performance

Construction & Design

The intake system features a precision-machined aluminum intake tube with a smooth, mandrel-bent design that minimizes airflow restrictions. The oversized synthetic filter is engineered for maximum airflow and filtration efficiency, helping to maintain engine cleanliness and performance over time. The included heat shield is custom-designed to fit the Subaru WRX STI, effectively blocking hot air from the engine bay and ensuring cooler intake temperatures.

Installation & Fitment

Installation is straightforward with all necessary hardware included. The system is designed as a direct bolt-on upgrade for 2019–2021 Subaru WRX STI models equipped with the 2.5L H4 engine, requiring no additional modifications or tuning for optimal performance.

What’s Included

The package includes the oversized synthetic washable air filter, mandrel-bent aluminum intake tube, custom heat shield, and all mounting hardware needed for a complete installation.

Ideal For

Performance enthusiasts looking to improve throttle response and engine efficiency, daily drivers seeking reliable power upgrades, and Subaru owners aiming to enhance their vehicle’s airflow with a durable, maintenance-friendly intake system.