FA20 Cylinder Heads: The Essential Upgrade Guide
You’ve added an intake, exhaust, and a tune, but your power gains have started to plateau. If this sounds familiar, you’ve likely found the hidden bottleneck in your engine: the cylinder heads. Forcing more air through an engine that can't process it efficiently is a recipe for disappointment. To truly get the most from your modifications, you need to improve your engine's ability to breathe. This is where upgrading your FA20 cylinder heads comes in. We’ll cover how ported heads and an improved valvetrain can transform your build, creating a more powerful and responsive driving experience.
Key Takeaways
- Upgrade for more power and durability: Stock FA20 cylinder heads can restrict your engine's potential. Upgrading them improves airflow to produce more horsepower and torque, while also providing the strength needed to reliably handle a larger turbo or increased boost.
- Choose heads that match your goals: The right cylinder heads depend on your power targets. A high-horsepower track build requires professionally ported heads and a full valvetrain upgrade, while a daily driver might only need a quality rebuilt set for a noticeable performance gain.
- Factor in professional work and a tune: This is not a DIY project. Professional installation is crucial for preventing engine damage, and a final ECU tune is required to recalibrate your engine for the new hardware, ensuring you get safe, optimized performance from your investment.
What Are FA20 Cylinder Heads?
Before you can appreciate the impact of an upgrade, it helps to understand what cylinder heads do. Think of them as the lungs of your engine. They sit on top of the engine block, sealing the combustion chamber and managing the flow of air and fuel in and exhaust out. For the FA20 engine found in Subaru models from 2012 to the present, including the WRX and BRZ, the cylinder heads are central to its performance and character. They house critical components like the camshafts, valves, and spark plugs, all working together to create power.
A Look Inside the FA20 Engine
The FA20 engine is a sophisticated piece of engineering, and its cylinder heads are a major reason why. They are designed to work with advanced systems like Toyota's D-4S direct and port injection, which helps create a more complete and efficient combustion cycle. This means better fuel economy and a more responsive throttle right from the factory. The heads are specifically designed to optimize the air-fuel mixture, ensuring every combustion event is as powerful as possible. This intricate design is the foundation upon which all other performance parts build.
Key Features of FA20 Heads
Not all FA20 heads are created equal. The naturally aspirated version in the BRZ, for instance, features heads with smaller ports and intake valves. This design keeps air velocity high, which is perfect for making power at higher RPMs without a turbo. In contrast, the FA20DIT in the WRX has heads built to handle the pressures of forced induction. For enthusiasts looking to push beyond stock limits, modifying the heads is a critical step. A built FA20 engine almost always includes ported cylinder heads and an upgraded valvetrain to dramatically improve airflow and support higher performance levels.
FA20 Heads vs. Other Cylinder Heads
Compared to older Subaru engine designs like the EJ series, the FA20 cylinder heads are a significant step forward in efficiency and design. However, when you start aiming for serious power figures, the stock heads can become a limiting factor. The factory castings are great for daily driving and light modifications, but they can't always flow enough air to support a larger turbo or high-boost applications. To handle the increased stress and airflow demands of a high-power build, upgrading the cylinder heads is essential for both performance and reliability, as explained in our complete guide to FA20 engine performance.
Why Upgrade Your FA20 Cylinder Head?
Think of your engine as a high-performance athlete. For it to perform at its peak, it needs to breathe efficiently. The FA20 cylinder heads are essentially the engine's lungs, controlling the flow of air and fuel in and exhaust out. While the stock heads on your Subaru are well-engineered for daily driving, they can become a significant bottleneck when you start chasing serious horsepower. Upgrading your cylinder heads is a foundational step for unlocking your engine's true potential, allowing it to handle more power reliably and make the most of other modifications.
An upgrade isn't just about swapping parts; it's about creating a more efficient, powerful, and durable engine. By improving how your engine breathes, you lay the groundwork for substantial performance gains, whether you're building a car for the track, the trail, or spirited street driving. It’s one of the most effective ways to ensure your entire setup works in harmony to produce impressive and reliable power.
The Performance Gains of an Upgrade
Upgrading your FA20 cylinder heads directly translates to more power, but it’s about more than just a peak horsepower number. A properly built set of heads with an upgraded valvetrain allows your engine to operate efficiently at higher RPMs and handle the increased stress from a turbocharger or other power adders. Ported heads, which have been modified to smooth out and enlarge the intake and exhaust passages, significantly improve airflow. This enhancement allows your engine to ingest more air and fuel, leading to more powerful combustion and, consequently, more horsepower and torque across the entire powerband. These modifications are essential for transforming your engine into a robust powerhouse that supports other performance parts.
Improve Airflow and Combustion
The core principle behind a cylinder head upgrade is optimizing airflow. The FA20 engine relies on a precise air-fuel mixture for efficient combustion, and the cylinder heads are central to this process. By redesigning the ports and combustion chambers, performance heads increase airflow velocity and volume. This means the cylinders fill with the air-fuel mixture more completely and expel exhaust gases more effectively. When you combine this superior airflow with the FA20’s advanced direct injection system, you get a more complete and potent combustion event. This efficiency doesn't just create more power; it can also improve throttle response, making your vehicle feel more alert and eager.
Support Your High-Power Build
If your plans for your Subaru include a larger turbo, increased boost, or a fully built short block, then upgraded cylinder heads are not just a recommendation; they're a necessity. The stock heads simply aren't designed to manage the extreme pressures and temperatures generated by a high-output engine. Upgraded heads are built with stronger materials and components, like improved valve springs and retainers, to prevent valve float at high RPMs and ensure durability. Reinforcing the top end of your motor is crucial for reliability, ensuring that your investment is protected. After installation, a professional tune is critical to recalibrate the engine's parameters, which is why comprehensive engine tuning services are essential to safely maximize your new setup's potential.
Exploring Top FA20 Cylinder Head Options
When you're ready to upgrade your FA20 cylinder heads, you'll find several trusted names in the Subaru performance world offering excellent solutions. Each shop has a slightly different approach, from comprehensive rebuild services to complete, ready-to-install packages. Understanding these options is key to choosing the right path for your build. Some builders focus heavily on maximizing airflow through meticulous porting and polishing, which is ideal for squeezing out every last bit of horsepower. Others prioritize durability, using stronger valvetrain components to handle the stress of high-revving, high-power applications. You'll also find convenient, all-in-one packages that take the guesswork out of matching components.
Looking at what top builders offer can help you understand what’s essential for your own project. Whether you're building a track monster, a reliable daily driver with more punch, or a high-horsepower street car, there's a cylinder head option that fits your goals. The following examples from leading experts provide a great roadmap for what to consider, from the importance of porting to the necessity of a robust valvetrain. By seeing how different specialists tackle the same challenge, you can make a more informed decision for your Subaru. Let's look at what some of them bring to the table.
Crawford Performance
At Crawford Performance, we see cylinder heads as a cornerstone of any serious FA20 build. To get the most out of your engine, especially when adding a turbo or other power modifications, you need to improve airflow. This is why a built FA20 almost always includes ported cylinder heads and an upgraded valvetrain. Porting smooths out the intake and exhaust paths, allowing air to move more freely, while a stronger valvetrain handles the increased stress of higher RPMs and more power. These aren't just minor tweaks; they are fundamental performance parts that allow your engine to breathe better and operate reliably under pressure, forming the foundation for significant power gains.
IAG Performance
IAG Performance also emphasizes that cylinder head upgrades are a critical part of the FA20 performance equation. They point out that as you increase power, you also increase stress on the entire engine assembly. To manage this, reinforcing the block and upgrading the cylinder heads for better airflow become necessary steps. This approach shows that head modifications are part of a holistic strategy for building a durable, high-output engine. It’s not just about bolting on a single part; it’s about ensuring the entire system works together. Their guide to FA20 performance reinforces that heads are a key component for anyone pushing their engine beyond stock limits.
GCH Longblock Racing
If you're looking for a more service-oriented solution, GCH Longblock Racing offers specialized rebuilt head packages for FA20 and FA20DIT engines. Instead of just selling parts, they provide a comprehensive rebuild process designed to improve both performance and long-term reliability. This is a great option if your current heads are still in decent shape but you want them professionally reworked for higher power levels. A rebuild package typically involves cleaning, inspecting, and machining the heads, along with installing upgraded components. This ensures you get a professionally prepared set of heads ready for your build without starting from scratch.
Outfront Motorsports
For those who prefer a complete, bolt-on solution, Outfront Motorsports provides a product tailored specifically for the 2015-2021 Subaru WRX with the FA20DIT engine. Their "Outfront Motorsports 600 Complete Cylinder Head Package" is an all-in-one kit designed for enthusiasts aiming for a specific performance level. This type of package takes the guesswork out of selecting individual components, as it comes pre-assembled with parts chosen to work together effectively. If you want a proven combination of valvetrain components and head preparation, exploring a complete cylinder head package like this can save time and ensure compatibility, making it a straightforward path to upgrading your engine.
What Performance Gains Can You Expect?
Upgrading your FA20 cylinder heads is a significant step toward building a more capable engine. While it’s easy to get focused on peak horsepower numbers, the real benefits are much broader. A well-designed set of heads improves the engine's overall efficiency, allowing it to breathe better, make more power reliably, and work seamlessly with other performance modifications. From noticeable gains in horsepower and torque to raising the ceiling for what your engine can handle, the right cylinder heads are a cornerstone of any serious build. Let's look at what you can realistically expect when you make this upgrade.
Real-World Horsepower and Torque Increases
The primary goal of upgrading your cylinder heads is to improve airflow into and out of the combustion chamber. Think of it like an athlete breathing; the easier they can breathe, the better they perform. Ported cylinder heads, which have been modified to smooth out and enlarge the air passages, allow your engine to take in more air and fuel. When paired with an upgraded valvetrain, your engine can process this increased flow more effectively, especially at higher RPMs. This directly translates to more power. A built FA20 engine with properly prepared heads will deliver significant gains in both horsepower and torque, creating a more responsive and exciting driving experience.
Understanding Power Handling Limits
Adding more power puts a lot more stress on your engine's internal components. Stock cylinder heads are designed for factory power levels, and pushing them too far can lead to failure. Upgraded heads are built from stronger materials and are designed to withstand the higher pressures and temperatures of a modified engine. This modification is crucial for reliability. To properly manage the increased stress of a high-power build, you often need to reinforce the engine block and upgrade the heads for better durability and airflow. This ensures your engine can safely handle the extra power you’re making, giving you peace of mind whether you're on the track or the street.
Compatibility with Forced Induction
If you’re running a turbo or supercharger, your cylinder heads play a critical role. Forced induction systems push pressurized air into the engine, so the heads need to manage that airflow efficiently. The FA20 heads were engineered with smaller ports to keep air velocity high, which helps with throttle response. When you add boost, this design helps fill the cylinders quickly and effectively. Furthermore, the FA20’s advanced direct injection system helps create an optimal air-fuel mixture, which is essential for efficient combustion under boost. For turbocharged platforms like the Subaru WRX, upgraded heads ensure you get the most out of your setup.
A Look at Materials and Construction
The performance of a cylinder head isn't just about its shape; it's deeply rooted in the materials used and the precision of its construction. The FA20 engine's heads are a great example of how smart engineering choices lead to impressive results right from the factory. When you decide to upgrade, you're building on this solid foundation. Understanding the "why" behind the design of both stock and aftermarket heads helps you make a more informed decision for your build. From the choice of metal to the shape of the air passages, every detail is engineered to manage heat, optimize airflow, and ultimately, make more power reliably.
The Benefits of Aluminum Construction
There’s a good reason Subaru chose aluminum for the FA20’s cylinder heads. This lightweight metal is a top performer in the automotive world, primarily because it helps reduce the engine's overall weight. A lighter engine contributes to better vehicle balance and more responsive handling, which you can definitely feel on the track or a winding road. Beyond its weight advantage, aluminum is excellent at dissipating heat. This is critical for a high-performance engine, as it helps prevent overheating and keeps temperatures stable under load. This effective thermal management allows for more aggressive tuning and a healthier engine long-term.
How Port Design Affects Airflow
The intake and exhaust ports in your cylinder heads are like the engine's respiratory system. Their design directly controls how efficiently air enters and exhaust exits the combustion chamber. The FA20 in the BRZ, for example, uses heads with smaller ports to keep air velocity high, which is perfect for a naturally aspirated engine that thrives at higher RPMs. When you introduce forced induction with a turbo or supercharger, the game changes. Aftermarket performance parts often feature ported heads with larger, reshaped passages. This modification improves the volume and smoothness of airflow, allowing your engine to breathe deeper and make significantly more power.
Essential Valvetrain Components and Upgrades
Inside the cylinder head is the valvetrain, a synchronized system of valves, springs, retainers, and camshafts that orchestrates the engine's breathing cycle. The stock valvetrain is designed for factory power levels, but it can become a weak point in a high-power build. Upgrading these components is essential for reliability and performance. Stronger valve springs prevent "valve float" at high RPMs, while more aggressive camshafts can alter the timing and duration of valve openings to optimize airflow for your specific setup. For any serious build, a fully upgraded valvetrain ensures your engine can safely handle the increased stress and higher revs that come with making more power.
How Much Do FA20 Cylinder Heads Cost?
When you start shopping for FA20 cylinder heads, you’ll quickly see that prices can vary quite a bit. The cost depends entirely on what you’re looking for. A basic, rebuilt set of heads might be your starting point, but a fully ported, high-performance package designed for the track will be a much larger investment. The final price tag is influenced by several key factors, including whether the heads are new or rebuilt, the extent of the modifications, and the quality of the internal components.
Think of it this way: you’re not just buying a piece of metal. You’re investing in the heart of your engine’s breathing system. The price reflects the level of engineering, labor, and hardware that goes into making your Subaru perform at its peak. Whether you’re building a reliable daily driver with a bit more punch or a full-blown race car, there’s a cylinder head option that fits your goals and budget. Understanding what drives the cost will help you make an informed decision for your build.
Breaking Down the Price Range
The cost of FA20 cylinder heads can range from around $1,000 to $6,000 or more. On the lower end, you’ll find rebuilt head packages, which are a great option for replacing a damaged head or for a mild street build. These typically involve cleaning and inspecting a used core and replacing any worn components. For those seeking serious power, high-end packages from performance shops can run from $3,000 to over $6,000. These heads are far from standard; they often include professional porting and polishing for maximum airflow, along with upgraded valves, springs, and retainers designed to handle high RPM and boost. These comprehensive performance parts are essential for anyone pushing their FA20 to its limits.
New vs. Rebuilt: What's the Difference?
Choosing between new and rebuilt cylinder heads comes down to your budget and performance goals. Rebuilt heads are a cost-effective solution that can restore performance without the expense of a brand-new part. In this process, a used head is disassembled, thoroughly cleaned, and inspected for any defects. Worn parts are replaced, surfaces are machined, and the head is reassembled to meet or exceed factory specifications. This makes them a reliable choice for many street applications. On the other hand, new cylinder heads offer the ultimate in quality and peace of mind, especially for high-horsepower Subaru WRX upgrades. They provide a pristine foundation with no history of wear or potential hidden flaws, making them the preferred choice for competitive racing or aggressive builds where every component counts.
Factors That Affect the Price
Several key upgrades directly influence the cost of FA20 cylinder heads. The most significant is porting and polishing, a meticulous process where the intake and exhaust runners are reshaped and smoothed to optimize airflow. This labor-intensive work can dramatically improve engine efficiency and power output. Another major factor is the valvetrain. Upgrading to stronger, lighter valves, stiffer valve springs, and titanium retainers allows the engine to safely handle higher RPMs and increased boost pressure. The camshaft profile also plays a role, as aggressive cams that provide more lift and duration cost more but are essential for maximizing power. Finally, the price often includes professional assembly and quality checks, ensuring every component works together perfectly before it ever reaches your engine.
What to Know Before You Install
Upgrading your FA20 cylinder heads is a significant step toward building a high-performance Subaru. But before you turn a single wrench, it’s crucial to understand that this isn't a simple weekend project. Proper installation and supporting modifications are just as important as the heads themselves. Getting this part right ensures you achieve the power gains you’re after while protecting your engine investment for the long haul. Think of it as building a complete system where every component works in harmony.
Why Professional Installation Matters
While the DIY spirit is strong in the Subaru community, installing cylinder heads is a job best left to the experts. This is a complex procedure that requires specialized tools, in-depth knowledge of the FA20 engine, and meticulous attention to detail. Incorrectly torqued bolts, improper timing, or a poorly sealed gasket can lead to catastrophic engine failure. Many manufacturers, including us, require professional installation to validate the warranty on high-performance components. An experienced technician ensures everything is assembled to precise specifications, giving you peace of mind and a solid foundation for reliable power.
Essential Supporting Mods for Your Upgrade
High-flow cylinder heads are designed to move more air, but they can't do it alone. To get the full benefit of your upgrade, you need to address the components around them. A built FA20 with ported heads often requires an upgraded valvetrain (springs, retainers, and valves) to handle higher RPMs and prevent valve float. You should also consider other performance parts that improve breathing, such as a high-flow intake, a less restrictive exhaust system, and upgraded camshafts. These supporting mods ensure your engine can efficiently use the increased airflow from your new heads, creating a balanced and powerful setup.
The Importance of a Post-Installation Tune
After your new cylinder heads are installed, a professional tune is not optional; it's essential. Changing the airflow dynamics of your engine requires a complete recalibration of the ECU. An expert tuner will adjust fuel maps, ignition timing, and other critical parameters to match the new hardware. Proper engine tuning services optimize combustion efficiency, allowing your engine to make more power safely. Skipping this step can result in poor performance, dangerous air-fuel ratios, and engine knock, potentially destroying the very components you just invested in. A final tune is what brings all your upgrades together and safely unlocks their true potential.
Where Should You Buy FA20 Cylinder Heads?
Once you’ve decided to upgrade, the next critical question is where to buy your FA20 cylinder heads. The source of your parts is just as important as the components themselves. A high-quality cylinder head from a questionable seller can lead to major headaches, from receiving counterfeit goods to having zero support when you need it most. Your engine build is a serious investment, and protecting it starts with choosing a reputable supplier who understands the intricacies of Subaru performance.
Making the right choice means looking beyond the price tag. You need a partner who can provide genuine parts, expert advice, and reliable support. Whether you prefer the convenience of online shopping or the hands-on approach of a local shop, the principles of vetting your supplier remain the same. Let’s break down the best places to find the cylinder heads that will form the foundation of your high-power build and ensure your project is a success from the start.
The Value of Authorized Dealers
When you’re investing in a component as critical as a cylinder head, buying from an authorized dealer is one of the smartest moves you can make. These sellers have a direct relationship with manufacturers and are held to a higher standard of quality and knowledge. An authorized dealer won’t just sell you a part; they provide the expertise needed to ensure it’s the right fit for your specific goals. They understand that to manage the increased stress of a high-horsepower build, you need performance parts that are proven to work together. This expertise is invaluable, saving you from costly trial-and-error and ensuring your engine operates reliably under pressure.
Shopping Online vs. Buying Locally
The debate between buying online or from a local shop comes down to balancing convenience, selection, and trust. Online retailers often offer a wider selection and more competitive pricing, giving you access to parts from across the globe. However, it’s crucial to purchase from a well-established specialist. A built FA20 requires ported cylinder heads to maximize airflow, and a reputable online store can guarantee you’re getting a professionally modified component. For example, browsing Subaru WRX upgrades from a trusted source ensures authenticity. Local shops offer the benefit of in-person advice and the ability to inspect parts firsthand, but their inventory may be limited. Whichever route you choose, prioritize suppliers with a strong reputation in the Subaru community.
Understanding Warranties and Support
Performance parts are a significant financial commitment, and a solid warranty is your safety net. Before you finalize a purchase, always ask about the warranty terms. What does it cover, and for how long? A reputable seller will stand behind their products with clear and fair warranty policies. Beyond the warranty, consider the level of post-purchase support. If you or your mechanic run into an issue during installation, will the seller be available to help? Companies that offer expert services like engine tuning typically provide a higher level of support because they have deep, hands-on knowledge of the products they sell. This combination of a strong warranty and accessible expert support gives you peace of mind.
How to Choose the Right FA20 Cylinder Head
Selecting the right FA20 cylinder heads is one of the most important decisions you'll make for your engine build. This isn't a one-size-fits-all upgrade; the best choice depends entirely on your specific goals, your vehicle, and your budget. Think of it as laying the foundation for your engine's performance. A well-chosen set of heads will work in harmony with your other components to deliver reliable power, while the wrong set can create bottlenecks or lead to costly failures. By carefully considering your needs, you can find the perfect match to support your build, whether you're aiming for a responsive daily driver or a track-ready powerhouse.
Match the Heads to Your Power Goals
Before you start shopping, ask yourself what you want to achieve with your Subaru. Are you building a 500-horsepower track car or just looking for a reliable bump in performance for street driving? Your answer will guide your decision. For high-power builds, ported cylinder heads with an upgraded valvetrain are essential. These modifications improve airflow and allow the engine to handle the increased stress from higher boost and RPMs. If your goals are more modest, a set of stock-port heads with upgraded springs and retainers might be all you need to achieve your desired performance without overspending. The key is to align the heads' capabilities with your engine's intended output and use.
Confirm Your Vehicle's Compatibility
Not all FA20 engines are created equal, and their cylinder heads reflect that. The heads on a turbocharged WRX are designed differently than those on a naturally aspirated BRZ or 86. For instance, the BRZ’s cylinder heads are engineered with smaller ports to keep air velocity high for better throttle response at higher RPMs. Trying to use them in a high-boost turbo application without modification would restrict airflow and limit your power potential. Always verify that the heads you’re considering are compatible with your specific model and year. Reputable manufacturers will clearly list which Subaru WRX upgrades or BRZ parts are interchangeable, so be sure to read the product details carefully.
Balance Your Budget with Performance Needs
Cylinder heads are a significant investment, so it’s important to find a balance between cost and capability. A brand-new set of fully ported heads with top-of-the-line valvetrain components represents the peak of performance and price. On the other hand, a professionally rebuilt set can offer excellent value for milder builds. When planning your budget, remember to account for the total cost of the project. This includes essential supporting performance parts like head gaskets and ARP head studs, as well as the cost of professional installation and a final tune. Investing in heads that far exceed your power goals can be an unnecessary expense, but cutting corners on a high-power build is a risk you don’t want to take.
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Frequently Asked Questions
When should I actually consider upgrading my FA20 cylinder heads? You should start thinking about a cylinder head upgrade when your power goals begin to exceed what simple bolt-on parts can support. If you plan to install a larger turbo, run significantly more boost, or build the engine for track use, the stock heads will become a major restriction. They are the key to improving your engine's breathing, so upgrading them is a foundational step for any serious, high-horsepower build.
What does "porting" my cylinder heads actually do? Porting is the process of reshaping and smoothing the intake and exhaust passages inside the cylinder head. Think of it as clearing a path for air to move more freely. This modification increases the volume and velocity of air flowing into and out of the engine. The result is more efficient combustion, which translates directly to more horsepower and torque across the entire RPM range.
Are upgraded heads necessary if I'm just adding a bigger turbo? Yes, they are highly recommended. A larger turbo forces much more air into the engine, and the stock cylinder heads simply aren't designed to handle that increased volume and pressure efficiently. Without upgraded heads, you create a bottleneck that limits the turbo's potential and puts unnecessary stress on the engine. Upgraded heads ensure your engine can use all that extra air effectively and reliably.
Why is a professional tune so important after installation? Installing new cylinder heads fundamentally changes how your engine breathes. A professional tune is required to recalibrate your vehicle's computer to account for this improved airflow. A tuner will adjust the fuel and ignition timing to optimize performance and ensure the engine runs safely. Skipping this step can lead to poor performance, dangerous air-to-fuel ratios, and potentially severe engine damage.
Is it better to buy a complete head package or have my stock heads rebuilt? This depends on your goals and budget. Having your stock heads professionally rebuilt and ported is a great, cost-effective option for many street and performance builds. A complete, pre-assembled package from a reputable builder is ideal for high-power applications, as it takes the guesswork out of matching components and often comes with parts engineered to work together for a specific performance level.