The Subaru BRZ / Toyota GR86 platform has become a darling of the enthusiast world, praised for its near-perfect balance, low curb weight, and accessible nature. But even the most dedicated driver occasionally craves more straight-line punch. While the stock 2.4-liter FA24 engine is a massive improvement over its predecessor, its 228 horsepower leaves room for serious boosting. Enter the Perrin 200–250 horsepower turbo kit. Perrin Performance has a storied reputation for building high-quality, bolt-on forced induction systems for Subaru and Toyota twins. This article provides a comprehensive technical breakdown of the Perrin turbo kit, examining the actual power gains, required supporting modifications, installation complexity, tuning requirements, and real-world performance expectations for your GR86.

What the Perrin Turbo Kit Delivers: Power Figures and Reality

The Perrin kit is engineered to produce a wheel-horsepower range between 200 and 250 hp above stock. However, it is critical to understand that this figure represents gain over baseline, not total output. A stock GR86 puts down roughly 200–210 whp (wheel horsepower) on a dynamometer. Adding 200–250 whp means a final drivetrain output in the neighborhood of 400–460 whp. This is a transformative level of power that completely changes the car’s character.

The exact gain depends on several variables:

  • Target boost pressure: The kit is designed to run safely at 8–10 psi on pump gas, but a more aggressive tune or higher-octane fuel (E85, race gas) can increase boost and power.
  • Fuel choice: Standard 91–93 octane pump gas will yield the lower end of the gain window. Switching to ethanol-based fuels (E85) allows significantly more timing and boost, pushing toward the upper 250 whp gain limit.
  • Engine tuning quality: A conservative “safe” tune might produce 200 whp gain, while an aggressive calibration from a reputable tuner can extract the full 250 whp without sacrificing reliability.
  • Supporting modifications: The kit’s advertised numbers assume a completely stock exhaust system. Adding a high-flow downpipe, a free-flowing cat-back exhaust, and a larger intercooler can increase gains by 10–20 whp.

Dynamometer Confirmed Results

Perrin’s own testing, third-party dyno sheets, and owner-reported runs consistently show a peak wheel-horsepower figure of 400 to 450 whp on 93 octane with the tune dialed in. This represents a roughly 210–240 whp gain over a stock car’s wheel number. On E85, customers have documented gains approaching 480 whp, which is right at the upper limit of the kit’s capacity and pushes the limits of the stock engine internals. For a car that originally weighs just 2,800 pounds, this is staggering performance — a power-to-weight ratio that rivals much more exotic machines.

Components of the Perrin Turbo System

Understanding what you are buying is essential. The Perrin kit is a comprehensive, bolt-on turbo system that includes nearly everything needed to add forced induction. Key components include:

  • Turbocharger: A Garrett GT3071R or similar ball-bearing turbocharger. This turbo is well-matched to the 2.4-liter’s flow characteristics, offering rapid spool and strong mid-range torque while still able to pull hard to redline.
  • Cast iron exhaust manifold: Perrin uses a thick-walled, equal-length manifold designed for durability and to minimize cracking under high heat loads. This is a critical reliability upgrade over thin-wall tubular manifolds.
  • Downpipe: A 3-inch downpipe with a high-flow catalytic converter (or catless option) that smoothly transitions exhaust gases from the turbo to the vehicle’s exhaust system.
  • Front-mount intercooler (FMIC): A large bar-and-plate intercooler with polished piping that reduces intake air temperatures. The intercooler is sized to handle sustained boost, preventing heat soak even during aggressive driving.
  • Blow-off valve (BOV): A recirculating blow-off valve that protects the turbo compressor wheel and improves throttle response on lift-off.
  • Fuel system upgrades (partial): The kit typically includes larger fuel injectors (around 700–800 cc/min) and a high-flow fuel pump to supply the increased fuel demand. For higher power levels on E85, a dedicated fuel pressure regulator may be necessary.
  • Charge piping and silicone hoses: All necessary joining sections with reinforced silicone couplers and T-bolt clamps for leak-free operation.
  • Oil and coolant lines: Stainless steel braided feed and drain lines for the turbo’s lubrication and cooling.

The kit is designed to be a “bolt-on” affair, meaning it uses factory mounting points and does not require cutting or welding (though some minor trimming of the plastic undertray may be needed). Perrin provides detailed installation instructions, but the complexity is high.

Installation: What to Expect

Installing the Perrin turbo kit is a significant project, best undertaken by a skilled mechanic with turbocharging experience. The job typically requires 12–20 hours of labor in a well-equipped shop. Important steps include:

  1. Prepare the vehicle: Drain coolant and oil. Remove the factory intake, airbox, exhaust manifold, front bumper, and various plastic shrouds. This grants access to the engine bay and front-core area.
  2. Mount the intercooler and charge piping: The FMIC is installed behind the front bumper, requiring removal and careful reinstallation of the bumper cover. The piping runs from the turbo outlet, through the intercooler, and then to the throttle body.
  3. Install the turbo manifold and turbocharger: The cast iron manifold bolts directly to the cylinder head. The turbo is then attached. Properly tightening these bolts to specification is critical to prevent exhaust leaks.
  4. Plumb oil and coolant lines: The oil feed line typically taps into the engine block’s oil gallery, while the drain line returns oil to the oil pan. Coolant lines are connected to the engine’s cooling system. Ensure all fittings are secure and that the drain line has a consistent downward slope to avoid oil coking.
  5. Install the downpipe and connect exhaust: The downpipe attaches to the turbo outlet and joins to the rest of the exhaust system (stock or aftermarket). A gasket is required.
  6. Install the blow-off valve and intake system: The BOV is mounted on the charge pipe, and a high-flow air filter connects to the turbo inlet.
  7. Fuel system upgrades: Replace the fuel pump (in-tank) and install the supplied larger injectors. If your kit includes them, install a boost-referenced fuel pressure regulator. This step requires work inside the fuel tank and on the engine intake manifold.
  8. Reinstall all factory components: Refit the bumper, undertray, and any other trim removed. Check clearance around the intercooler piping to ensure nothing rubs or vibrates.
  9. Final checks: Fill with fresh oil and coolant. Prime the turbo by disconnecting the fuel pump relay and cranking the engine until oil pressure registers. Then reconnect, start, and inspect for leaks.

Critical: The engine cannot be started without a proper tune. The ECU must be reprogrammed with a calibration that accounts for the much higher air mass flow and fuel requirements. Running the engine with the stock tune will cause immediate lean condition and catastrophic engine failure.

Tuning: Unlocking the Power Safely

The Perrin kit is an “open” system — it does not come with a pre-loaded ECU map. Tuning is handled by an aftermarket solution. The most common options are:

  • ECUtek – The preferred platform for Subaru / Toyota twin tuners. Allows full manipulation of timing, fuel, boost control, and all safety parameters. A professional remote or dyno tune from a reputable tuner (e.g., Delicious Tuning, Corbin’s, or a local specialist) is highly recommended.
  • OpenFlash Tablet (OFT) – A more budget-friendly option with some pre-loaded base maps, but the Perrin kit’s larger turbo and fuel system requires a custom tune for optimal results.
  • Haltech / MoTeC standalone ECU – Rarely needed for this power level but useful for extreme builds with E85 and high boost.

Tuning for the Perrin kit involves calibrating the fuel injector slope and latency, adjusting the ignition timing curve, setting boost targets via the wastegate solenoid (if using stock boost control), and modifying throttle mapping. A good tuner will also dial in knock control, cold-start enrichment, and all safety limiters (e.g., torque limit in low gears to protect the drivetrain). The resulting power curve is smooth and linear, with boost building strongly from around 3,500 rpm and pulling hard to the 7,400 rpm redline.

Supporting Modifications: What Else Do You Need?

Installing 400+ whp into a chassis that originally had 200 hp demands upgrades in several areas. At minimum, consider the following:

Clutch

The stock clutch will slip immediately under full boost. A heavy-duty single disc clutch (e.g., ACT, Spec, Exedy Stage 2) is mandatory. For higher power with E85, a twin-disc clutch is recommended for long-term durability and pedal feel.

Cooling System

More power = more heat. The stock radiator may be sufficient for casual driving, but track days require an upgraded aluminum radiator (e.g., Koyo, Mishimoto) and an oil cooler. The Perrin intercooler handles intake temps well, but the engine coolant system needs extra capacity to maintain stable temperatures under sustained load.

Exhaust System

The kit includes a downpipe, but the rest of the exhaust (cat-back) should be at least 2.5–3 inches in diameter to prevent backpressure. A louder aftermarket exhaust is common, but be aware of local noise regulations.

Suspension and Brakes

With 400+ whp, the stock brakes will fade quickly on track. Upgrading to track-oriented pads (e.g., Ferodo DS2500, Endless MX72) or a big brake kit (e.g., StopTech, AP Racing) is wise. The lowered stance of the car should be supported by quality coilovers (e.g., Öhlins, KW) to handle the increased weight transfer and cornering forces.

Drivetrain

The stock Torsen limited-slip differential can handle the power but benefits from a supplemental cooler if the car will be tracked. The transmission (AZ6 / Aisin AY6) is sturdy but the shift forks can bend under repeated high-rpm shifts; a shift stop kit and upgraded bushings help. Axles may become a weak point above 450 whp.

Reliability: Will It Last?

The FA24 engine, found in the GR86, has proven to be a robust platform. The closed-deck block design (inherited from Subaru’s turbocharged lineage) and forged connecting rods in the late-2022+ models mean the short block is capable of handling around 500 whp on pump gas with a good tune. However, the pistons are still hypereutectic and can crack under detonation. The Perrin kit at its designed power level (400–450 whp) is within the safe zone of the engine’s capacity, provided:

  • Fuel quality is maintained (premium 93 or better, or adequate ethanol content).
  • Oil changes are frequent (3,000 miles with high-quality full synthetic 5W-30 or 5W-40).
  • The tune includes robust knock detection and pull timing.
  • The intercooler is kept clean and free of debris to maintain IATs.

Many owners have reported 20,000–30,000 miles without major issues on the Perrin kit when driven responsibly. Track use and repeated high-rpm acceleration will accelerate wear, but the kit itself is designed for long-term enjoyment rather than a short-lived power rush.

Real-World Experiences and Owner Feedback

Online forums (GR86.org, FT86Club, Facebook groups) are filled with owner reviews. Common threads include:

  • Spool characteristics: The GT3071R spools quickly. Owners report peak boost by 3,500–3,800 rpm, making the car feel much torquier in daily driving. The power delivery is linear, not an on/off switch.
  • Exhaust note: The turbocharger quiets the exhaust slightly compared to a naturally aspirated setup, but the induction noise and BOV whoosh are addictive.
  • Drivability: The car remains easy to drive gently. The tune can be set for part-throttle smoothness; full throttle is unleashed only when asked. Many describe it as “a different car” that retains its original character but is vastly faster.
  • Reliability feedback: Some early adopters experienced minor coolant leaks at barb fittings or loose charge pipe clamps, but these are simple fixes. Engine failures are rare and usually traceable to poor tuning or fuel issues, not the kit itself.

Cost: Total Investment

The Perrin 200–250 hp turbo kit itself retails for approximately $5,500–$7,500, depending on the fuel system components included (with or without injectors and pump). Installation by a shop will add $1,500–$3,500 in labor. Tuning via ECUTek with custom calibration adds another $800–$1,500. Supporting modifications (clutch, cooling, exhaust) can add $2,000–$5,000. Total investment to do it right: roughly $10,000–$18,000 on top of the car’s purchase price. This is not cheap, but it yields a truly exhilarating machine that can embarrass far more expensive sports cars.

Alternatives to Consider

The Perrin kit is not the only option for turbocharging the GR86. Competitors include the HKS GT III supercharger kit (which offers immediate throttle response but lower top-end power), the Full Race turbos (custom setups with support), and the Blitz / GReddy turbo kits. For those wanting less power, a simple tune and intake can yield modest gains, but the Perrin kit occupies a sweet spot for those who want serious, reliable forced induction without a complete engine rebuild.

Conclusion

The Perrin 200–250 HP Turbo Kit is a well-engineered solution that transforms the GR86 from a darty momentum car into a legitimate performance weapon. With proper installation, a quality tune, and necessary supporting modifications, owners consistently report gains of 400–450 whp on pump gas and up to 480 whp on E85. The power increase is substantial but linear, preserving the car’s driving dynamics while adding a massive thrill factor. Yes, the investment is significant, but for an enthusiast seeking the ultimate street and track experience from the twin platform, the Perrin turbo kit is a proven, reliable path to achieving it.