Table of Contents
Understanding the Goal: 300 Wheel Horsepower on the FA24
The Subaru BRZ with the FA24 engine (2022+) is already a capable platform, but many enthusiasts find the stock power output leaves room for improvement. Reaching 300 horsepower at the wheels (whp) is an attainable and popular target that dramatically transforms the car’s character without demanding a built block or forced induction. The FA24 responds well to bolt-on modifications paired with a proper ECU tune. The two pillars of this upgrade path are an optimized exhaust system—specifically from Borla—and a custom or off-the-shelf (OTS) engine calibration. This guide breaks down every cost involved so you can budget accurately and avoid surprises.
Why Borla Exhaust? And Which System Fits Your Budget
Borla offers several exhaust configurations for the BRZ FA24. The choice affects both peak horsepower and the total cost. The key is improved exhaust flow, which reduces backpressure and allows the engine to breathe more freely, especially after a tune.
Borla Cat-Back Exhaust Systems
A cat-back system replaces everything from the catalytic converter back to the tips. It’s the most common first step. Borla’s S-Type and ATAK cat-back systems are popular; the S-Type offers a moderate sound increase, while the ATAK is more aggressive. Prices range from $1,000 to $1,400 depending on the specific model and retailer. Installation is relatively straightforward and can often be done at home with basic tools, saving on labor.
Borla Header (Exhaust Manifold) Options
For maximum gains, you will want a set of equal-length headers. Borla produces headers for the FA24 that significantly improve exhaust scavenging. A header replacement can add 15–25 whp on its own when tuned. Expect to pay between $900 and $1,200 for a quality set. Pairing a header with a cat-back is the most effective way to unlock flow for a 300 whp target.
Borla Axle-Back vs. Full System
An axle-back ($600–$900) is cheaper but only changes the sound and does little for power. To reach 300 whp, a full cat-back (or cat-back plus header) is necessary. The cost of a complete Borla system (header + cat-back) will fall in the $1,900–$2,600 range. You may also find deals from authorized dealers or during seasonal sales.
ECU Tune: The Brains Behind the Power
An exhaust alone will not get you to 300 whp. The factory ECU calibration is conservative and will not compensate for increased airflow. You need a tune—either an off-the-shelf (OTS) flash or a custom dyno tune.
Off-the-Shelf (OTS) Flash Tune
Several reputable tuners offer OTS maps for the BRZ FA24 with bolt-on mods. These are pre-written calibrations meant to work with specific parts (e.g., Borla cat-back + intake). Prices range from $500 to $800 for the software license and the tune file. You will also need a tuning device such as an OpenFlash Tablet (around $700) or an ECUTek dongle (with cable, around $500–$700).
| Item | Estimated Cost |
|---|---|
| ECUTek Dongle + Cable | $500–$700 |
| Custom or OTS Tune | $500–$1,200 |
| OpenFlash Tablet (OFT) + Tune | $700 (includes basic OTS maps; custom map extra) |
An OTS tune is the budget option. It will safely get you close to 300 whp, especially with a cat-back and header.
Custom Dyno Tune
For maximum power and safety, a custom tune from a reputable shop (like Delicious Tuning or CTS Turbo) is recommended. You will drive the car to a dyno facility, and the tuner will recalibrate the ECU on the rollers. This accounts for your exact mods, fuel quality, and environmental conditions. Dyno time plus tuning labor typically costs $1,000–$2,000. The final result is often a cleaner, more powerful curve, and you are more likely to hit 300 whp reliably.
Supporting Mods: The Hidden Costs
To safely reach and sustain 300 whp, a few supporting modifications are strongly advised. These add to the total cost but protect your engine.
Cold Air Intake
An aftermarket intake (e.g., from AEM or K&N) improves airflow into the engine. It is not strictly necessary with a full exhaust and tune, but it helps. Budget $300–$500 for a quality intake.
Upgraded Front Pipe & Over-Pipe
If you install a header, you should also consider a high-flow front pipe (eliminating the secondary cat) and an over-pipe. These help spool and flow. Borla does not make these, but brands like Perrin or HKS do. Combined cost: $300–$600.
Clutch Upgrade (for 300 whp target)
The stock FA24 clutch is marginal at 300 whp. If you do autocross or hard launches, plan to replace it with a stronger unit (Exedy Stage 1 or South Bend DI). That is an extra $400–$800 plus installation labor.
Tuning Device Rental (if not buying)
Some tuners allow you to borrow/rent an ECUTek dongle for an additional fee. If you only plan one tune, renting can save money. Expect $100–$200 rental fee.
Installation Costs: DIY vs. Professional Labor
Installing a cat-back exhaust is an easy DIY job needing basic jack and stands (or ramp). Headers are more involved and often require removing the intake manifold or subframe. Professional labor rates are typically $100–$150 per hour.
- Cat-back installation: 1–2 hours → $100–$300
- Header + over-pipe installation: 3–5 hours → $300–$750
- Full system (header + cat-back + front pipe): 5–7 hours → $500–$1,050
- Clutch job: 4–8 hours → $400–$1,200
If you are not mechanically inclined, these costs can quickly add up. Many shops also charge a fee to load the tune or perform a base dyno pull.
Total Cost Breakdown: From Economy to Premium Builds
Let’s calculate three realistic scenarios for reaching 300 whp.
| Scenario | Parts & Tune | Total Estimated Cost |
|---|---|---|
| Budget OTS with Cat-Back | Borla S-Type Cat-Back ($1,300), ECUTek dongle + OTS tune ($1,200), DIY install ($0) | $2,500 |
| Header + OTS, Professional Install | Borla Header ($1,100) + Cat-Back ($1,300), OFT ($700) with custom map ($300), labor ($600) | $4,000 |
| Premium Dyno Tune with Full Exhaust & Clutch | Full Borla system ($2,400), custom dyno tune ($1,800), clutch ($700), labor ($1,000) | $5,900 |
As you can see, the range is wide. The minimum viable cost for 300 whp is about $2,500 if you already have tools and do the work yourself. For a turn-key, reliable build, budget closer to $5,500–$6,000.
Warranty and Reliability Considerations
Modifying the exhaust and ECU will void certain portions of your factory warranty, particularly powertrain coverage. Discuss this with your Subaru dealer before proceeding. Some tuners offer “warranty-friendly” options like a piggyback tune that can be removed, but these are less effective than a full ECU reflash. For reliability, stick with reputable tuners and use quality parts. An overly aggressive tune on stock internals can lead to rod bearing failure. The FA24 is robust, but 300 whp is near its safe limit without supporting upgrades like oil cooling or a catch can (add ~$200–$400).
External Resources
- Borla Official Website – verify part numbers and specifications.
- ECUTek Global – for tuning hardware and dealer locator.
- FT86 Club FA24 Forum – community dyno results and build logs for cost comparison.
Final Verdict
Upgrading your Subaru BRZ FA24 to 300 whp with a Borla exhaust system and an ECU tune is a rewarding project that sharpens the car’s already excellent handling with potent straight-line performance. The cost ranges from about $2,500 (DIY budget build) to $6,000 (professional full package). The key is to prioritize a quality tune above all else—cheap ECU calibrations can cause engine damage. Pair that with a well-matched Borla exhaust (cat-back and header) and your BRZ will sound as good as it goes. Plan your upgrades carefully, budget for supporting mods and labor, and enjoy the process of building a truly driver-focused sports car.