How Much Power Does the FA24 Actually Make: Stock and Built

The FA24 is the engine powering the 2022 and newer Subaru WRX and one of the most common questions from owners planning a build is simple: how much power does it actually make? Stock numbers, bolt-on numbers, built numbers. This guide gives Subaru WRX owners on the FA24 platform a clear answer at every stage of the build.

What Is the FA24 and How It Differs From the FA20

The FA24 is a 2.4-liter turbocharged boxer engine introduced in the 2022 WRX. It replaced the FA20, which powered the WRX from 2015 to 2021. The displacement increase from 2.0 to 2.4 liters gives the FA24 more low-end torque and a broader, flatter power band compared to the FA20. It also runs a twin-scroll turbocharger with an electronic wastegate, which improves spool response over the previous generation.

The FA24 is a different engine family from the EJ25 used in the STI. It shares architecture with the FA20 but is not a direct evolution of it. For a full breakdown of how the two WRX platforms compare, the FA20 vs FA24 guide covers everything owners need to know about both generations.

FA24 Stock Power Output

From the factory, the FA24 WRX produces 271 horsepower and 258 lb-ft of torque at the crank. At the wheels, accounting for drivetrain losses through the AWD system, most owners see between 225 and 240whp on a stock car on a dyno. The exact number varies depending on conditions, dyno type, and tune state.

Compared to the FA20, the FA24 makes slightly more power from the factory and delivers it across a wider RPM range. The broader torque curve makes the car feel stronger in daily driving and gives the build more to work with before hitting the stock turbo ceiling.

FA24 Power With Bolt-On Mods

The FA24 responds well to bolt-on modifications. A COBB Accessport with an off-the-shelf map is the first and most impactful upgrade — most owners see 20 to 30whp improvement on pump gas from the tune alone. Adding an intake and exhaust to the Accessport tune delivers a further 15 to 25whp on top of that.

E85 is where the FA24 really opens up. The higher octane of E85 allows significantly more aggressive ignition timing, which translates to meaningful power gains over pump gas. On a properly tuned FA24 with a flex fuel setup, 300 to 330whp at the wheels is a realistic target on E85 with bolt-ons only. The COBB CAN flex fuel upgrade for 2022-2025 WRX covers how the flex fuel system works on the FA24 platform specifically.

Browse WRX bolt-on upgrades to see the full range of bolt-on options available for the FA24 platform.

FA24 Power With a Turbo Upgrade

The stock FA24 turbo has a ceiling. Once the bolt-ons are in place and the tune is dialed, a turbo upgrade is the next meaningful step for owners targeting more power. The larger displacement of the FA24 compared to the FA20 means it feeds a bigger turbo more efficiently, which supports stronger power delivery at higher boost levels.

On a properly supported FA24 with a turbo upgrade, E85, and a pro tune, 400 to 450whp at the wheels is achievable with the right hardware combination. Supporting fueling, intercooler, and a tune written for the specific setup are all required to reach those numbers reliably. Browse WRX turbo and airflow upgrades to compare options for the FA24 platform, or check the best turbo upgrades for WRX post for specific recommendations.

For FA24F owners who want the most complete bolt-on turbo solution available, IAG Performance has released the IAG 600 Ball Bearing Turbocharger for 2022+ WRX FA24F. Proven at 374 WHP on 93 octane and 450 WHP on E60 fuel on a stock engine, it is the most purpose-built FA24 turbo upgrade currently available.

What Does a Built FA24 Support

The FA24 built engine ecosystem is newer than the mature EJ25 market. The EJ platform has decades of aftermarket development behind it. The FA24 is catching up quickly but the range of built engine options is still developing compared to what is available for the EJ.

What is known is that the FA24 block responds well to closed deck conversion and forged internals in the same way the EJ family does. Built FA24 combinations targeting 500whp and above are achievable with the right short block foundation and full supporting mods. The WRX engine build guide covers how to plan a built FA24 around a specific power goal. Browse IAG short block options for WRX to see what is available for the FA24 platform.

FA24 vs FA20: Which Platform Has More Built Potential

The honest answer is that the EJ25 ecosystem is more mature. More tuners have worked with it, more built engine options exist, and the aftermarket support is deeper across every category. For owners on the 2015 to 2021 FA20 WRX, the built engine path is well established.

The FA24 is closing that gap. The larger displacement gives it a natural power advantage at stock and bolt-on levels. As the aftermarket catches up on built engine solutions, the FA24 will likely support higher power ceilings than the FA20 because of that displacement advantage. For owners deciding between platforms or generations, the FA20 vs FA24 comparison covers everything relevant to that decision.

Plan Your FA24 Build

The FA24 is a strong platform with real performance potential at every stage. Stock numbers are competitive. Bolt-ons on E85 push well past 300whp. A turbo upgrade with proper support reaches 400whp territory. A built short block opens the door to 500whp and beyond as the aftermarket continues to develop solutions for the platform.

Start with the WRX performance upgrades hub to map out the full upgrade landscape by stage. The WRX engine reliability guide covers how to protect the FA24 at each power level as the build grows.