The Subaru BRZ is celebrated for its balanced chassis and nimble handling, but its naturally aspirated FA20 engine leaves many enthusiasts craving more thrust. For those seeking a significant power upgrade without the complexity of a full standalone engine management system, the Mishimoto 7-10 PSI turbo kit has become a go-to solution. This kit is engineered to deliver a reliable, substantial horsepower increase while retaining drivability. But exactly how much power can you expect? Let’s break down the numbers, the engineering behind the kit, and what it takes to unlock its full potential.

Mishimoto Turbo Kit: Engineering and Components

Mishimoto’s offering isn’t just a collection of generic parts; it’s a carefully matched system designed specifically for the Subaru BRZ (and its twins, the Scion FR-S and Toyota GT86). The kit targets a moderate boost level of 7 to 10 PSI, which allows the use of the stock engine internals while still providing a night-and-day difference in power delivery. The complete system includes:

  • MHI TD04HL-19T turbocharger – A proven, reliable turbo that spools quickly and delivers strong mid-range torque.
  • Cast iron exhaust manifold – Designed to withstand high temperatures and reduce the risk of cracking compared to tubular log-style manifolds.
  • Front-mount intercooler (FMIC) – Lowers intake air temperatures to prevent detonation and maintain power consistency.
  • Aluminum charge piping – Smooth mandrel-bent tubing minimizes flow restriction.
  • Colder-range spark plugs – Pre-heat-treated to avoid misfire under boost.
  • 3-inch downpipe – Increases exhaust flow velocity, reducing backpressure.
  • Oil feed and drain lines – Proper lubrication and drainage ensure turbo longevity.
  • Mishimoto intercooler piping kit – Includes all silicone couplers and T-bolt clamps.
  • ECU reflash or tune – A base calibration is included, but custom tuning is strongly recommended for maximum power and safety.

This kit is a complete solution; no additional parts (besides a boost controller if you want to adjust boost pressure) are required for installation. The factory fuel system is sufficient up to the 10 PSI boost level, though some users upgrade to 550cc injectors for headroom when running E85.

Baseline Horsepower: Where the BRZ Starts

To understand the gain, you must first know the baseline. A stock Subaru BRZ (2013–2020) produces approximately 200 horsepower at the crankshaft per the factory specification, but at the wheels (whp) the number typically falls between 165 and 175 whp on a chassis dyno, depending on the tune, ambient conditions, and transmission losses. The FA20 is a 2.0-liter naturally aspirated boxer engine with a high 12.5:1 compression ratio. That high compression limits the amount of boost you can safely run without internals upgrades, which is why the Mishimoto kit restricts boost to 10 PSI maximum.

How Much Horsepower Does the Mishimoto 7-10 PSI Kit Add?

Real-world dyno testing and owner reports consistently show that the Mishimoto turbo kit adds between 70 and 100 wheel horsepower at the 7–10 PSI boost range. This translates to a final output of roughly 240 to 275 whp on a pump gas tune (93 octane or 98 RON). On the crank, that is approximately 290 to 330 horsepower. The variation depends on the specific boost pressure (7 vs. 10 PSI), the quality of the custom tune, and the car’s additional bolt-on modifications.

Dyno Results Breakdown

On an independent dynojet run with a stock long block, 93 octane fuel, and the kit set to 9 PSI, Mishimoto themselves recorded 270 whp and 240 lb-ft of torque. That is a gain of roughly 100 whp over a typical stock BRZ. Another popular tuner, Delicious Tuning, published results showing 255 whp at 8 PSI with their calibration. These numbers are consistent across dozens of community build threads. To put it in perspective: a stock BRZ takes about 6.5 seconds to 60 mph; with this turbo kit, that time drops to around 4.5–4.8 seconds with a good tune and sticky tires.

For the most accurate and current dyno graphs, consult Mishimoto’s official product page or community resources like this FT86Club build thread.

Factors That Influence Final Horsepower Gains

No two BRZ turbo installs yield identical results. Several variables affect the final whp number:

Engine Condition and Mileage

A high-mileage engine with carbon buildup on the intake valves or worn piston rings will not compress air as efficiently, potentially reducing gains by 5–15 whp. Compression and leak-down tests are recommended before boosting.

Fuel Quality and Octane

Higher octane (93 or 100 RON, or ethanol blends) allows more aggressive ignition timing and boost pressure. Running 91 octane will force the tuner to pull timing, often resulting in 10–20 whp less than with 93. E85 can push outputs to over 300 whp with the same kit.

Exhaust and Intake Modifications

Adding a cat-back exhaust and a high-flow intake (the kit includes a cone filter, but you can upgrade to a larger cold air intake) can free up additional airflow. Pairing the kit with a full 3-inch exhaust system often yields an extra 10–15 whp.

Tuning Quality

The included base tune is safe and conservative. A professional custom tune from a shop like Delicious Tuning or a local dyno tuner can extract every last horsepower by optimizing air-fuel ratios and ignition timing. A poor or generic tune can cost you 20–30 whp and even risk engine damage.

Ambient Temperature and Elevation

Dyno numbers are measured at sea level under standard conditions. At high altitude (above 2,000 ft), the thinner air reduces turbo efficiency, lowering output. Hot summer days also increase intake air temps, causing the ECU to pull timing.

Installation: What to Expect

Installing a turbo kit on a BRZ is not an afternoon job. Mishimoto estimates 8–12 hours for a skilled DIY mechanic, and more for a novice. The process involves removing the intake manifold, exhaust manifold, front bumper, and fuel system components. Mishimoto provides detailed instructions, but several steps require special tools (e.g., a torque wrench for turbo bolts and a scan tool to bleed the coolant system).

If you lack mechanical experience, professional installation is highly recommended. Improperly routed oil lines can starve the turbo of lubrication, and misaligned charge pipes can cause boost leaks that dramatically reduce power. A reputable Subaru performance shop will typically charge between $800 and $1,500 for the install, depending on your region.

Can You DIY It?

Yes, but only if you are comfortable with engine bay wiring, fuel system modifications, and working under the car. The kit’s components are designed to fit without cutting or welding, but expect to remove the radiator and fans. Several online guides and videos (e.g., this installation walkthrough) can help. However, the tuning phase after installation is equally critical and should be done by a professional.

Tuning: The Key to Safe Power

The Mishimoto kit ships with a base calibration that is safe to start the engine and drive the car to a tuner, but it is not optimized. The stock ECU can be reflashed via an EcuTek cable (sold separately). There are three main tuning approaches:

  • Off-the-shelf (OTS) calibration – Mishimoto’s included tune is conservative (around 240 whp). Good for daily driving, but leaves power on the table.
  • EcuTek custom reflash – A remote tuner or dyno shop adjusts the fuel and timing maps for your specific car. This typically yields 260–275 whp with 93 octane.
  • Standalone ECU (e.g., Haltech, Motec) – Overkill for a 7–10 PSI street kit, but allows full control including flex fuel and launch control.

Most owners opt for a custom reflash. The tuner will perform several dyno pulls, adjusting the fuel injector pulse width and ignition timing to avoid knock. Expect to pay $400–$800 for a custom tune, plus the cost of an EcuTek license ($300–$500).

Real-World Driving Impressions

Numbers only tell part of the story. Drivers report that the biggest change is in mid-range torque. The stock FA20 feels anemic below 4,000 RPM; after the turbo, boost builds strongly from 2,800 RPM onward, making the car feel significantly faster in everyday traffic. Highway passing becomes effortless, and the car pulls hard all the way to its 7,400 RPM redline. The flat torque curve (peaking around 3,500–5,000 RPM) transforms the BRZ into a responsive street machine.

That said, the kit does add weight (about 35 lbs) and changes the car’s balance slightly. Some owners report increased oversteer tendency due to the added power, which can be managed with a proper alignment and upgraded tires. The additional heat from the turbo also requires a better oil cooler for track use, though Mishimoto includes a high-capacity oil cooler as an optional add-on.

Reliability Considerations

Running 7–10 PSI on the stock FA20 is considered safe by most tuners, but it does not mean you are immune to failure. The high compression ratio (12.5:1) makes the engine more knock-prone than a typical 9:1 turbo motor. Octane quality and tune safety are paramount. Mishimoto’s kit is designed to keep temperatures in check, but repeated track sessions or aggressive daily driving on 91 octane can lead to ringland failure (a common issue in forced-induction FA20s). Using a quality oil (5W-30 synthetic, changed every 3,000 miles), monitoring intake air temps with a Bluetooth OBD-II scanner, and avoiding sustained full-throttle runs on hot days will extend engine life.

Cost vs. Value

The Mishimoto turbo kit retails for approximately $2,800–$3,200, depending on the retailer and whether you buy the full package (includes intercooler, piping, and all hardware). Factor in installation ($1,000), tuning ($600), and optional supporting mods (clutch upgrade ~$500, oil cooler ~$400), and the total investment is around $5,000–$6,000. For that, you gain roughly 100 whp—a cost of about $50–$60 per horsepower. That is excellent value compared to supercharger kits (which often cost $4,000+ for similar gains) or a full engine build (easily $8,000+).

Moreover, the kit retains the stock driveability: no idle issues, no excessive heat soak, and the car can still pass emissions inspections in most states (the tune must be set to “emissions ready” with functioning O2 sensors).

Is the Mishimoto Kit Right for You?

This kit is ideal for the BRZ owner who wants a noticeable, daily-driveable power increase without sacrificing reliability. It is not a drag-strip monster (you would need higher boost and internals for that), but it transforms the car into a genuinely quick sports car. If you are already considering forced induction, the Mishimoto kit offers a proven, bolt-on solution with a solid reputation in the BRZ community.

For comparison, some competitive options include the Jackson Racing supercharger kit (linear power delivery, lower peak torque) and the Perrin turbo kit (more expensive, higher boost potential). But at the 7–10 PSI level, Mishimoto strikes an excellent balance of cost, power, and reliability.

Final Verdict

To answer the core question directly: the Mishimoto 7-10 PSI turbo kit adds between 70 and 100 horse power to the wheels on a Subaru BRZ, translating to a final output of roughly 240–275 whp. With a quality tune and proper maintenance, this upgrade provides a transformative driving experience—making the BRZ feel as quick as it looks. Whether you are autocrossing, canyon carving, or simply commuting with a smile, this kit delivers the power most enthusiasts crave.