The Subaru BRZ has long been celebrated as one of the most engaging driver’s cars available, especially for road course enthusiasts. Its lightweight chassis, perfect 50/50 weight distribution, and low center of gravity make it an ideal platform for track days. However, the factory 2.0-liter FA20 engine—rated at 205 horsepower (or 200 hp in earlier models)—leaves many drivers wanting more straight-line punch. With a modest budget of around $1,200, you can unlock up to 50 additional horsepower through a well-planned combination of bolt-on upgrades and tuning. This guide details the top 10 modifications that deliver the best bang for your buck, helping you shave seconds off your lap times without breaking the bank.

Before diving into the list, it’s important to understand that horsepower gains are not simply additive. Many of these modifications work synergistically, especially when paired with a proper ECU calibration. The total estimated gain of 50 hp assumes you combine at least half of these upgrades and optimize them together. Prioritize modifications that address airflow, fuel delivery, and ignition first; then fine-tune the drivetrain and suspension to maximize track performance.

1. ECU Tune

Estimated gain: 10–20 hp | Cost: $300–$600 (includes custom tune or off-the-shelf flash)

The single most effective upgrade for any modern fuel-injected car is an ECU (Engine Control Unit) recalibration. The factory map is conservative, designed for emissions and fuel economy. A quality tune optimizes air-fuel ratios, ignition timing, and throttle response. On the BRZ, an off-the-shelf tune from brands like Delicious Tuning or a custom dyno tune can unlock 15–20 hp on a stock engine. If you combine it with a cold air intake and exhaust, gains can exceed 25 hp.

Installation tip: Most BRZ tunes require an OpenFlash Tablet or ECUTek cable. Follow the tuner’s instructions to read the factory ROM, flash the new file, and log data for fine-tuning. If you’re not comfortable with self-tuning, a professional dyno session is worth the extra cost.

2. Cold Air Intake

Estimated gain: 5–10 hp | Cost: $150–$350

A cold air intake (CAI) replaces the restrictive factory airbox with a free-flowing filter and a tube that draws cooler air from outside the engine bay. The BRZ’s engine responds well to reduced intake restriction, especially at higher RPM. Intakes from FT86 SpeedFactory, AEM, or Perrin offer proven gains of 5–10 hp. For road courses, a sealed cold air box (like the Grimmspeed unit) is recommended to avoid heat soak during extended sessions.

Installation tip: Use a torque wrench for the MAF sensor screw to avoid cracking the housing. Re-oil the filter every 10,000 miles if it’s a reusable cotton type.

3. High-Performance Exhaust System

Estimated gain: 5–15 hp | Cost: $200–$700

Replacing the factory exhaust reduces back pressure and allows the engine to exhale more freely. A cat-back or axle-back system is the most popular entry-level option, typically adding 5–8 hp. For greater gains, consider a full header-back system with a catless front pipe, but be aware of emissions regulations. The Tomei Unequal Length Header paired with a resonated front pipe can yield up to 15 hp while giving the BRZ a classic Subaru boxer rumble.

Track note: Many road course organizations require a maximum noise limit. Choose an exhaust with a removable silencer or a reputation for staying under 95 dB at idle.

4. Lightweight Flywheel

Estimated gain: 5 hp (improved throttle response) | Cost: $250–$400

A lightweight flywheel reduces rotational inertia, allowing the engine to rev faster both up and down. This doesn’t directly add horsepower, but it feels like 5 hp in real-world acceleration because the engine spends less time spooling between gears. An 11–13 lb flywheel (stock is ~22 lbs) is a popular upgrade for track-focused BRZs. Brands like ACT, Exedy, and Fidanza offer durable options.

Installation tip: This job requires removing the transmission, so it’s best done when you’re also replacing the clutch or doing other drivetrain work. Use new flywheel bolts and threadlocker.

5. Performance Spark Plugs

Estimated gain: 2–5 hp | Cost: $40–$80

While spark plugs alone won’t transform your BRZ, performance plugs ensure consistent ignition, especially under high heat and load. Iridium or platinum plugs with a cooler heat range can reduce misfires and improve combustion efficiency. For the FA20, NGK LFR7AIX or Denso Iridium Power are solid choices. Gains of 2–5 hp are possible when combined with a tune and other breathing mods.

Installation tip: Gap the plugs to the engine builder’s spec (typically 0.032–0.035 inches). Use anti-seize on the threads and a torque wrench to 20 Nm.

6. Upgraded Fuel Injectors

Estimated gain: 5–10 hp (with tune) | Cost: $200–$400

The BRZ’s stock fuel injectors (200 cc/min) are adequate for mild bolt-ons, but they become a restriction when adding a header, intake, and aggressive tune. Upgrading to 300–400 cc injectors from Injector Dynamics or DeatschWerks allows the engine to deliver more fuel at higher RPM. Combined with a tune, this can free up 5–10 hp and improve throttle response.

Track tip: If you plan to run E85, larger injectors are essential. E85 requires roughly 30% more fuel volume than pump gas.

7. High-Flow Air Filter

Estimated gain: 2–3 hp | Cost: $30–$60

If you’re not ready for a full cold air intake, a drop-in performance air filter (like K&N or AEM DryFlow) is a cheap way to improve airflow. It replaces the factory paper element with a reusable cotton or synthetic media. Expect a modest 2–3 hp gain, but more importantly, it complements other intake modifications. For road courses, a dry-flow filter is preferred because it doesn’t require oiling and is less likely to contaminate the MAF sensor.

Maintenance: Clean and re-oil (if applicable) every 20,000 miles or after a dusty track weekend.

8. Short Shifter Kit

Estimated gain: 0 hp (but faster shifts) | Cost: $100–$250

A short shifter reduces the throw distance by 30–50%, enabling quicker gear changes. While it doesn’t add horsepower, it directly improves lap times by reducing time between shifts and minimizing missed gears. The BRZ’s factory shifter is good, but upgrades from Kartboy, Cobb, or Billetworkz provide a more precise, notchy feel. Many kits also include a stiffer bushing to eliminate slop.

Installation tip: Most kits use the factory shift lever base; you just swap the lever and bushings. Use lithium grease on the pivot ball.

9. Suspension Upgrades (Coilovers & Sway Bars)

Estimated gain: Not direct horsepower, but lower lap times | Cost: $600–$1,200 (coilovers) or $200–$400 (sway bars)

To fully exploit extra horsepower, you need a suspension that keeps the tires planted. Budget-friendly coilovers from Raceberndt or Fortune Auto offer adjustable damping and ride height, lowering the center of gravity and reducing body roll. Pair them with a 22 mm rear sway bar to dial out understeer. While these don’t add horsepower, they can drop lap times by 2–3 seconds on a 1.5-mile course.

Setup note: For road courses, aim for a spring rate around 7k/8k (front/rear) and a ride height that maintains proper suspension geometry. Corner balance the car if possible.

10. Lightweight Wheels

Estimated gain: 0–5 hp (via reduced rotational mass) | Cost: $600–$1,200 (set of four)

Lightweight wheels reduce unsprung weight and rotational inertia, improving acceleration, braking, and cornering grip. A savings of 5–10 pounds per corner is equivalent to a small horsepower gain in real-world feel. Budget-friendly options like Enkei RPF1 (15–17 lbs) or Konig Hypergram are popular for the BRZ. For the $1,200 budget, you can find a quality set of 17x8 wheels wrapped with 235/40R17 track tires.

Weight vs. strength: Lighter wheels can be more fragile. For track use, choose flow-formed or forged construction over cheap cast wheels to avoid bending under kerb strikes.

Prioritizing Your $1,200 Budget

To achieve the full 50 hp goal, allocate your budget carefully. A typical high-impact path might look like:

  • ECU Tune: $500 (20 hp gain)
  • Cold Air Intake: $250 (8 hp)
  • Cat-back Exhaust: $400 (6 hp)
  • High-Flow Filter & Spark Plugs: $100 (5 hp combined)
  • Lightweight Flywheel (used or DIY labor): $150 (5 hp equivalent)

That’s roughly $1,400—about $200 over budget—but you can save by buying used parts or doing your own installation. The remaining 6 hp can come from a performance air filter or by upgrading fuel injectors later.

Conclusion

The Subaru BRZ is a rewarding platform for road course drivers who value precision over raw power. With $1,200 and the upgrades outlined above, you can extract up to 50 horsepower while also improving throttle response, shift feel, and cornering stability. Remember that a proper ECU tune is the cornerstone of any power-adding strategy—without it, even the best bolt-ons will underperform. Start with the tune, then layer on intake, exhaust, and lightweight drivetrain parts. For more detailed installation guides and dyno results, consult resources like FT86 Club or MotoIQ. Hit the track and enjoy the transformation—your BRZ will feel like a completely different car.