Dream Build Subaru EJ20

The Subaru EJ20 engine holds a legendary status in the world of performance tuning. From dominating the World Rally Championship (WRC) to powering countless modified street cars, the EJ20 is a favorite among racing enthusiasts. As every tuner knows, pushing the EJ20 to its limits—whether chasing big horsepower or ensuring rock-solid reliability—requires more than just bolt-on mods.

When it comes to tuning the EJ20 for high horsepower and ultimate performance, the crankshaft plays a pivotal role. Stock EJ20 crankshafts, while adequate for lower-power builds, simply can't handle the increased stresses of turbocharging, high RPMs, and high-horsepower applications. Enter the forged crankshaft—an essential upgrade for anyone looking to push the limits of their EJ20 engine.

Why a Forged Crankshaft?
A forged crankshaft is not only stronger but also more reliable than a stock cast crankshaft. The forging process compresses the metal, increasing its density and strength, making it far more capable of withstanding the intense forces generated in high-performance builds. Whether you're running a large turbo or building a stroker engine, a forged crankshaft ensures that the heart of your engine can handle the strain, providing you with the peace of mind needed to push the power limits of your Subaru.

KingTec Racing’s forged crankshafts are specifically designed for serious performance builds, engineered with precision to handle the most demanding driving conditions—from street use to extreme track environments. With our crankshaft, you’re not just getting a component; you’re getting the foundation for an engine that can take whatever you throw at it.

How to Optimize Your EJ20 Build?

Upgrading to a forged crankshaft is a crucial first step in building a high-performance Subaru EJ20 engine. But to truly unleash the full potential of your engine, it’s important to ensure that the rest of your build is up to the task. A forged crankshaft doesn’t work in isolation—it needs to be paired with complementary upgrades to maximize both performance and reliability. Let’s explore how you can optimize your EJ20 build and achieve a reliable, powerful engine that thrives on both the street and the track.

While the forged crankshaft is a vital upgrade, the true strength of your engine comes from ensuring the entire bottom end is built for performance. For this reason, pairing KingTec Racing’s forged crankshaft with our EJ20 forged pistons and connecting rods is the best way to ensure maximum durability and performance.

KingTec Racing’s EJ20 forged pistons and rods are designed to withstand the increased pressures and stresses of high-performance builds. While stock components might handle mild modifications, they often fail when subjected to the extreme conditions associated with turbo upgrades or displacement increases. KingTec Racing’s EJ20 forged pistons are made from premium 4032 alloys and are engineered to handle higher boost pressures, temperatures, and RPMs without warping or failing. Similarly, our EJ20 forged connecting rods are precision-engineered with the perfect balance of strength and lightness to withstand the intense forces generated in high-performance builds.

By integrating EJ20 forged internals, your engine will not only be more resilient but also more responsive. The seamless compatibility of KingTec Racing’s forged crankshaft, pistons, and connecting rods ensures a perfectly balanced bottom end, which is essential for smooth operation and consistent performance.

Turbo upgrades are at the heart of most EJ20 builds. Whether you’re opting for a Garrett GTX3582R or a BorgWarner EFR series, the added boost places enormous stress on the engine’s internal components. These upgrades deliver a massive increase in power, but they also push your engine beyond stock capabilities. To safely handle this surge in performance, the integrity of your rotating assembly is paramount.

A forged crankshaft is non-negotiable for turbo builds exceeding stock power levels. High-boost applications put immense pressure on the crankshaft, leading to twisting, flexing, and potential failure if stock components are used. KingTec Racing’s forged crankshaft is designed to prevent these issues, offering enhanced strength and rigidity to handle the extra forces generated by large turbochargers. By eliminating the risk of failure under high boost, our forged crankshaft ensures consistent performance and longevity, giving you the confidence to push your turbo system to its limits.

When building a high-performance engine, don’t overlook the importance of high-quality bearings. Bearings are critical to the smooth operation of your engine’s rotating assembly, and investing in top-tier bearings is essential for minimizing friction, wear, and the risk of failure. Low-quality bearings can cause premature engine wear, especially when paired with high-stress modifications like a forged crankshaft and turbo upgrades.

KingTec Racing recommends using performance-grade main and rod bearings designed to handle the increased loads and stresses of a high-powered EJ20. When paired with the forged crankshaft, high-performance bearings ensure the engine operates smoothly at higher RPMs and under boost, reducing the risk of premature engine failure and improving overall reliability.

Investing in the right bearings is a relatively small cost compared to the peace of mind it provides when pushing your EJ20 to its limits.

Even the best components will underperform if not assembled and tuned correctly. Professional assembly and precise tuning are crucial to ensuring that your high-performance EJ20 build reaches its full potential. A properly assembled engine, with all components balanced and aligned to exact specifications, not only performs better but also lasts longer.

Engine balancing is key to reducing vibration and stress on critical components, including the forged crankshaft. When an engine is unbalanced, it can lead to uneven wear, excessive friction, and potential failures. By ensuring that your crankshaft, pistons, rods, and other components are perfectly balanced, you reduce the chances of premature damage and optimize performance.

Similarly, tuning is a critical factor in getting the most out of your EJ20. A well-tuned engine maximizes fuel efficiency, power output, and drivability while preventing issues such as detonation or knock. Professional tuning should include adjusting the fuel and ignition maps to match the capabilities of the forged crankshaft and other internal upgrades. This ensures that the engine operates efficiently and reliably, with the perfect balance of power and safety.

As you increase the power output of your EJ20, managing heat and fuel delivery becomes even more important. High-performance components like the forged crankshaft generate more heat, and a failing cooling or fueling system can lead to catastrophic engine damage.

Upgrading your cooling system with a high-flow radiator, larger intercooler, and improved oil cooling can help maintain optimal operating temperatures. Additionally, upgrading the fuel system—whether with larger injectors, a higher-flow fuel pump, or an upgraded fuel regulator—ensures that your engine receives enough fuel to support higher boost levels and power demands.

By focusing on cooling and fueling in addition to internal engine components, you’re ensuring that your EJ20 remains safe and reliable under heavy load.

Frequently Asked Questions (FAQ)

Forged crankshafts offer significantly greater strength and durability compared to stock cast crankshafts. They are essential for high-horsepower or high-RPM applications.

Our crankshafts are precision-engineered with advanced forging and balancing techniques. They’re tested to ensure reliability and performance in the most demanding conditions.

While it’s possible to install the crankshaft with the right tools and expertise, we recommend professional assembly to ensure proper fitment and balancing.

We recommend pairing the crankshaft with forged pistons, connecting rods, high-performance bearings, and a professional tune for optimal results.

The Subaru EJ20 is more than just an engine—it’s a platform for endless performance possibilities. By upgrading to KingTec Racing’s forged crankshaft, you’re investing in the foundation of a truly high-performance build. Whether your goal is to dominate the track or enjoy a spirited drive on the street, our crankshafts deliver the strength, reliability, and precision you need.

Ready to unlock your EJ20’s potential? Explore our full range of performance products and start your journey with KingTec Racing today!