When the Subaru BRZ received the FA24 engine for its second-generation model, expectations soared. Enthusiasts who had already mastered the first-generation platform were eager to exploit the larger displacement and updated architecture. Now, with more than a hundred owners having taken delivery and implemented various performance modifications, a clear picture of real-world results has emerged. This article aggregates that collective experience, exploring what works, what doesn't, and what numbers these builds are actually delivering.

Understanding the FA24 Potential

The FA24D is a 2.4-liter direct-injected boxer engine rated at 228 horsepower and 184 lb-ft of torque from the factory—a solid improvement over the previous 2.0-liter FA20. However, owners quickly discovered that the stock tuning leaves significant headroom. Early dyno runs reported conservative air-fuel ratios and timing curves, suggesting that the engine was detuned from the factory for emissions and reliability margins. This unlocked immediate gains with basic calibrations.

According to data compiled from owner forums and a long-running FT86Club thread, the most common baseline mods (ECU tune, cat-back exhaust, drop-in air filter) yielded an average increase of 25-35 wheel horsepower. Several owners reported peaks over 260 wheel horsepower on 93 octane with a full bolt-on setup and professional tuning, a figure that would have required forced induction on the FA20.

Most Common Modifications and Their Outcomes

ECU Tuning

Removing the factory ECU restrictions is almost always the first step. Owners overwhelmingly favor open-source tuning solutions like Cobb Tuning’s Accessport or standalone ECUs from ECUTek. The gains are immediate: smoother throttle response, elimination of the rev hang, and a noticeable bump in midrange torque. On dyno sheets, a conservative Stage 1 tune (no hardware) nets 15–20 hp and 15–20 lb-ft at the wheels. Stage 2 tunes with intake and exhaust push that to 30–40 hp.

Intake and Exhaust Systems

Cold air intakes are popular, though results vary. High-quality units from Perrin, Grimmspeed, and Injen show consistent gains of 5–8 hp with proper tuning. Exhaust upgrades—especially cat-back or axle-back systems—provide sound improvements and modest power gains. The best setups are those that maintain proper backpressure for naturally-aspirated powerbands; a few owners who installed overly large piping (3-inches or more) reported loss of low-end torque, a common pitfall. The consensus is that a 2.5-inch cat-back paired with a mid-pipe and sport cat is ideal for the FA24.

Headers and Exhaust Manifolds

Upgrading the exhaust headers (often called “UEL” for uneven length or “EL” for equal length) is where the chassis’ true character emerges. Owners opting for unequal-length headers report a deeper, classic boxer rumble but minimal peak power gains—typically 5–10 hp. Equal-length headers, by contrast, can deliver 10–15 hp with better torque curve but sacrifice the unique sound. Several forum posts note that EL headers paired with a tune provide the best overall powerband for autocross and track use.

Real-World Acceleration Data

Scouring owner reports from drag strips, street testing, and even a few VBOX logs, the improvements in 0–60 mph and quarter-mile times are consistent. A stock 2022+ BRZ typically runs 0–60 in the 5.4–5.6 second range. With a Stage 2 tune and exhaust, many owners report times between 4.9 and 5.1 seconds. Some aggressive setups (tune, header, intake, and lighter wheels) have dipped into the high 4.7–4.8 second range—impressive for a naturally-aspirated sports car under $35,000.

One owner, tracked via a private Facebook group survey of 45 cars, shared that the best quarter-mile trap speed among modified FA24 BRZs was 98 mph (stock traps around 93 mph). That’s a gain of about 5 mph, translating into an ET improvement of roughly half a second. These numbers align with expectations for a 2.4L engine seeing a ~15% power increase.

Handling and Suspension Enhancements

The BRZ’s chassis has always been its trump card, and the FA24 model benefits from stiffer suspension bushings and revised geometry from Subaru. Nonetheless, owners upgrade to tighten things further. Coilovers from Ohlins, KW, and Fortune Auto are frequently cited. The most common feedback: dialing in camber plates and adjustable sway bars transforms turn-in response. Owners who installed Whiteline or Cusco sway bars report a 2–3 mph increase in slalom speeds and improved confidence in high-speed corners.

Brake upgrades are also a recurring theme. Stock brakes fade quickly under repeated hard stops on track days. Many owners swap to Carbotech or Hawk pads with high-temp fluid. A few have installed Brembo or StopTech kits, but the consensus is that fresh pads and braided lines are sufficient for lapping sessions of up to 20 minutes.

Owner Testimonials and Community Insights

Direct quotes from owners remain the most compelling evidence. Here is a selection drawn from forum posts, Facebook groups, and Reddit r/BRZ:

  • Tom H., Colorado: “I spent about $2,700 on a Cobb Stage 2 package (Accessport, intake, cat-back). The car pulls hard from 3,500 rpm all the way to redline. The biggest surprise was how much smoother the transmission shifts after the tune killed the rev hang.”
  • Emily R., California: “Installing Ohlins Road & Track coilovers was the best money I spent. The stock suspension was too soft for autocross. Now I get 2 degrees negative camber front and rear, and the car rotates perfectly.”
  • Marcus D., Texas: “As a first-gen owner, I was skeptical about the FA24. But after a year with a tune and EL headers, I’m consistently beating stock Mustang EcoBoost times at the track. Reliability has been flawless—over 20,000 miles with no CEL or oil consumption.”
  • Lucas J., Florida: “The only mod I regret was a 3-inch cat-back. Lost torque and drone on the highway. Swapped it for a 2.5-inch GReddy and the car came alive again.”

Challenges and Considerations

No performance journey is without obstacles. Owners have reported several recurring issues:

  • Fuel quality sensitivity: The FA24 is knock-prone on 91 octane. Owners in regions with low-octane fuel often need a tune optimized for 91 or run octane booster.
  • Warranty concerns: Subaru has been known to deny warranty claims for engine failures if a tune is detected. Many owners accept the risk, but some choose to keep mods minimal during the first 36,000 miles.
  • Clutch upgrade required for high power: Around 270+ wheel horsepower, the stock clutch starts slipping under hard shifts. Owners planning to add headers and a tune long-term budget for an ACT or Exedy clutch.
  • Noise/Comfort trade-offs: Stiffer suspension and louder exhaust can turn a daily driver into a chore. Several owners have reverted to stock springs for long road trips.

Cost vs. Benefit Analysis

Based on owner-reported spending and dyno figures, a well-rounded Stage 2 build costs between $2,500 and $4,000. The gains are substantial: a car that feels significantly faster, handles more confidently, and produces a more engaging exhaust note. Compared to forced induction (which requires expensive intercoolers, oil coolers, and internal upgrades for the FA24), naturally-aspirated bolt-ons deliver a higher “fun per dollar” ratio for most street drivers.

For those on a tighter budget, the best bang-for-buck is an ECU tune alone ($500–$700). It unlocks the engine’s latent potential without compromising daily drivability. Many owners attest that this alone makes the BRZ feel like a different car.

Conclusion: The Verdict from the Community

Over 100 owner reports confirm that the BRZ FA24 responds exceptionally well to performance modifications. The engine is overbuilt from the factory, the chassis is a willing partner, and the aftermarket support is robust. While challenges exist—fuel sensitivity, warranty concerns, and occasional driveline upgrades—the overall sentiment is overwhelmingly positive. The consensus among enthusiasts is clear: with careful selection of parts and a quality tune, the second-generation BRZ can be elevated to a level of performance that rivals cars costing twice as much.