SUBARU EJ25 ENGINE | SUBARU S401 ENGINE | SUBARU S402 ENGINE

Description

Unveiling the Legends: Subaru EJ25, S401, and S402 Engines

Subaru has built a reputation for producing rugged, reliable, and performance-oriented vehicles, and at the heart of this engineering marvel is their array of exceptional engines. Among the most revered in Subaru’s performance lineup are the EJ25, S401, and S402 engines. Each has its own unique history and contributions to Subaru’s legacy. Let’s dive into the details and see what makes these engines stand out.

The Subaru EJ25 Engine: A Classic in the Making

Overview

The Subaru EJ25 engine is a 2.5-liter flat-four (boxer) engine that has become one of Subaru’s most iconic powerplants. Introduced in the late 1990s, the EJ25 was designed to offer a blend of performance, reliability, and unique engine characteristics.

Design and Performance

The EJ25 features a horizontally opposed four-cylinder design, which provides a low center of gravity and enhances vehicle stability. This layout also contributes to reduced engine vibration, offering a smoother ride. The engine’s design results in a more compact engine bay and a lower overall vehicle height, which can significantly improve handling.

Power output varies depending on the specific model and year, but it typically produces around 165 to 173 horsepower. This power, combined with Subaru’s symmetrical all-wheel-drive system, provides excellent traction and stability across various driving conditions.

Applications

The EJ25 engine was used in several Subaru models, including the Legacy, Outback, and Forester. It became particularly popular in the Subaru WRX STI for its reliability and performance, making it a favorite among enthusiasts.

The Subaru S401 Engine: A Collector’s Gem

Overview

The Subaru S401 is a more exclusive and specialized engine, featured in the limited-edition Subaru Impreza WRX STI S401. This engine, introduced in the early 2000s, represents Subaru’s commitment to pushing the boundaries of performance engineering.

Design and Performance

The S401 engine is essentially a tuned version of the EJ25, developed to deliver higher performance figures. It boasts a turbocharged setup with increased boost pressure, resulting in a significant power increase. The S401 engine produces around 280 horsepower, which was a substantial upgrade over the standard EJ25.

This engine was mated to a six-speed manual transmission and featured advanced suspension components, making the S401 an exhilarating car to drive. It also came with unique styling cues and a sportier interior, further distinguishing it from the standard WRX STI.

Exclusivity

The S401 was a limited-production model, making it highly sought after by collectors and enthusiasts. Its rarity and performance enhancements have made it a standout in Subaru’s performance lineup.

The Subaru S402 Engine: The Pinnacle of Subaru Performance

Overview

Following the success of the S401, Subaru introduced the S402 engine as an even more refined and potent option for the Impreza WRX STI. The S402 was unveiled as part of Subaru’s celebration of its motorsports achievements, embodying the pinnacle of performance engineering.

Design and Performance

The S402 engine builds upon the foundation laid by the S401 but takes performance to the next level. With improvements in turbocharging, engine internals, and tuning, the S402 produces approximately 320 horsepower. This engine is paired with advanced suspension systems and a host of other performance enhancements to ensure that the S402 delivers an exceptional driving experience.

The S402 also features unique styling elements and a more aggressive aerodynamic package, highlighting its status as a high-performance machine. It combines blistering acceleration with precise handling, making it a true driver’s car.

Legacy and Impact

Like its predecessor, the S402 was produced in limited numbers, enhancing its allure among collectors. Its performance capabilities and exclusivity have solidified its place as one of Subaru’s most coveted models.

Conclusion

The Subaru EJ25, S401, and S402 engines each hold a special place in Subaru’s performance history. From the reliable and versatile EJ25 to the high-performance S401 and the pinnacle S402, these engines represent Subaru’s dedication to engineering excellence. Whether you’re an automotive enthusiast or simply curious about Subaru’s engineering prowess, these engines are a testament to the brand’s commitment to performance and innovation.