Introduction

Adding a turbocharger to your Subaru BRZ via a bolt-on boost kit is one of the most effective ways to unlock serious horsepower and torque. These kits are designed to simplify the installation process, but success still depends on careful preparation, precise execution, and proper tuning. This expanded guide walks you through every critical step—from gathering the right tools to dialing in your tune—so you can enjoy reliable, high-performance gains without unnecessary headaches.

Preparation Before Installation

A successful turbo installation starts before you touch a single bolt. Organizing your workspace, gathering the correct tools, and understanding the kit’s components will save hours of frustration.

Tools and Equipment Checklist

  • Complete bolt-on turbo kit (typically includes turbocharger, manifold, wastegate, blow-off valve, oil/coolant lines, gaskets, and mounting hardware)
  • Metric socket set (10mm, 12mm, 14mm, 17mm, 19mm) and extensions
  • Torque wrench (0–150 ft-lb range)
  • Pry bar and trim removal tools
  • Jack stands and a hydraulic floor jack
  • Safety glasses and mechanic’s gloves
  • Shop rags, drain pan, and brake cleaner
  • Boost gauge and wideband air-fuel ratio gauge (for monitoring after installation)
  • Fresh engine oil (5W-30 or as recommended by the turbo kit), coolant (Subaru Super Coolant or equivalent)
  • Thread locker (medium strength) and copper anti-seize

Workspace Setup

Work in a well-ventilated area with ample lighting. A lift is ideal, but a pair of strong jack stands and a low-profile jack will get the job done on the garage floor. Clear the area of clutter and lay down cardboard to catch drips. Disconnect the battery before starting—this prevents accidental short circuits and resets the ECU for the initial start-up.

Pre-Installation Engine Prep

Perform a basic compression test on the FA20 engine to confirm it’s healthy. Stock BRZ engines are robust, but a low reading in any cylinder suggests you should address issues before adding boost. Also check for existing oil leaks—turbocharging will amplify them. Replace the spark plugs if they’re due for a change, and consider upgrading to a colder heat range (e.g., NGK LFR7AIX) to handle increased cylinder pressures.

Step-by-Step Installation Guide

The installation process typically takes 8–12 hours for a first-timer. Work methodically and refer to your kit’s specific instructions—bolt-on kits from companies like FT86 Speed Factory or Grimmspeed may have nuanced differences in routing or hardware.

1. Remove Stock Components

Start by draining the engine oil and coolant to avoid spills when you disconnect the oil pan and coolant hoses. Remove the following:

  • Stock exhaust manifold (unbolt from cylinder heads and mid-pipe; may require soaking bolts with penetrating oil)
  • Intake manifold (label vacuum lines and electrical connectors)
  • Heat shields and splash guards under the engine bay

Disconnect the oxygen sensors and set them aside carefully. With the factory parts out, inspect the threads on the cylinder head studs—clean them with a wire brush if necessary.

2. Install the Turbocharger and Manifold

Mount the turbo manifold to the cylinder head using new gaskets supplied in the kit. Apply a light coating of anti-seize to the manifold studs to prevent galling. Tighten in a cross-pattern sequence to the manufacturer’s torque spec (typically 25–30 ft-lb for the FA20).

Position the turbocharger onto the manifold mounting flange. Ensure the compressor housing is oriented correctly for your intake routing. Most bolt-on kits use a T25 or T3 flange. Secure the turbo with the supplied lock washers and bolts, torquing evenly. Spin the compressor wheel by hand—it should rotate freely with no binding.

3. Route Oil and Coolant Lines

Correct lubrication is critical to turbo longevity. The oil feed line usually taps into the engine block near the oil filter housing, while the return line drains into the oil pan. If your kit does not include an oil pan bung, you will need to drill and weld a -10AN return fitting—this requires removing the oil pan completely. Many bolt-on kits now use a sandwich plate between the oil filter and block to simplify the feed.

Coolant lines typically tee into the heater core hoses or the coolant crossover pipe. Use hose clamps on all connections. Prime the turbo before starting the engine: disconnect the ignition or fuel pump relay, crank the engine for 10–15 seconds to build oil pressure, then reconnect. This step prevents dry start damage.

4. Install the Intake and Exhaust Systems

Fit the turbo intake pipe and air filter. Position the filter in a cool, low-turbulence location (behind the headlight or in the bumper area). Reconnect the blow-off valve to the intake pipe and ensure the vacuum reference line is secure.

For the exhaust side, bolt the downpipe to the turbo outlet and connect it to the rest of the exhaust system. Use a new gasket at every joint and apply high-temp anti-seize to the oxygen sensor threads. Check for clearance around the steering shaft, subframe, and sway bar.

5. Finalize Connections

  • Connect the boost reference line to the wastegate actuator and blow-off valve (if boost-actuated).
  • Install the intercooler and piping (if your kit is intercooled) – ensure all couplers and T-bolt clamps are tight.
  • Reconnect the battery.
  • Refill engine oil to the proper level and add coolant (bleed the cooling system to remove air pockets).

Post-Installation Checks

Before you fire up the engine, go through this checklist to catch mistakes that could cause immediate damage.

  • Visual inspection: Look for pinched hoses, loose clamps, or tools left in the engine bay.
  • Leak test the intake system: Pressurize the charge pipes to 15 psi using a smoke machine or a dedicated boost leak tester. Listen for hissing.
  • Prime the oil system: As mentioned, crank the engine with the fuel pump disconnected for 10–15 seconds. Watch the oil pressure gauge—if you see pressure, you’re good.
  • Start the engine: Let it idle and check for exhaust leaks at manifold and downpipe connections. A soapy water spray on turbo coolant lines will reveal bubbles if there’s a leak.
  • Monitor gauges: Ensure the boost gauge reads vacuum at idle (around -18 to -22 inHg) and rises smoothly when revved. The wideband A/F ratio should read 14.7:1 during idling.

Tuning Your BRZ After Installation

A bolt-on turbo kit without proper tuning is a recipe for detonation and engine failure. The stock ECU cannot compensate for the additional airflow and fuel demand. You will need a reflash or a piggyback tuning solution.

Choose a Tuning Method

  • Open-source tuning (RomRaider, ECUFlash): Free but requires learning and a Tactrix cable. Best for experienced tuners.
  • ECU reflash (Cobb Accessport, ECUTek): More expensive but user-friendly. Many tuners offer off-the-shelf maps for common bolt-on kits (e.g., ECUTek’s Subaru tuning platform).
  • Standalone ECU (Haltech, MoTeC): Overkill for a basic bolt-on kit but gives full control if you plan for larger turbos and E85.

Fuel System Upgrades

At 8–10 psi of boost (common for a bolt-on kit), the stock fuel pump and injectors may suffice, but they will be near their limits. For reliability, upgrade to a 255 LPH fuel pump and 550–700 cc injectors. This also allows headroom for E85 if available in your area.

Conservative Base Tune

Start with low boost (5 psi) and conservative ignition timing. Gradually increase boost to the kit’s intended level while monitoring knock, exhaust gas temperatures (EGTs), and wideband readings. Keep air-fuel ratios between 11.5:1 and 12.0:1 under full throttle. If you are not comfortable tuning yourself, hire a professional—the cost is a fraction of a blown engine.

Boost Controller and Wastegate Setup

Most bolt-on kits come with a fixed spring wastegate. An electronic boost controller allows you to adjust boost levels from the cockpit. Set the wastegate spring preload first (typically 6–8 psi), then use the controller to dial in higher boost safely. Always log data when making changes.

Common Issues and Troubleshooting

Even with careful installation, gremlins can appear. Here are the most frequent problems and how to solve them.

Low Boost / Lack of Power

Check for boost leaks at every coupler and flange joint. A smoke test is the quickest way. Also verify the wastegate actuator is fully closing—if it sticks open, boost will not build. Listen for a hissing sound while revving the engine.

Oil Leaks

The oil return line is the usual culprit. Ensure the drain tube has a constant downhill slope to the oil pan with no kinks. If the return is too small or angled upward, oil will back up and force out of the turbo seals. Also check the oil feed line banjo bolt washers—they must be replaced every time.

Overheating

A turbocharger adds heat load to the cooling system. Upgrade to a Koyorad or CSF aluminum radiator and ensure the cooling fan shrouds are intact. Air pockets in the coolant system also cause temperature spikes; use a spill-free funnel to burp the system thoroughly. Consider an oil cooler if you track the car.

Check Engine Light (CEL)

Common codes include P0171 (lean) and P0172 (rich). Both point to a tuning issue or a vacuum leak. Post-catalyst O2 sensor codes (P0420) may appear if the downpipe removes the catalytic converter—a tune with O2 sensor defeat logic resolves this.

Conclusion

Installing a bolt-on turbo kit on your Subaru BRZ is a hands-on project that rewards patience and attention to detail. By preparing thoroughly, following a methodical installation sequence, and investing in proper tuning, you can transform your BRZ into a responsive, high-horsepower machine that’s still reliable for daily driving. Take your time, don’t skip the leak tests, and always prioritize data logging to keep the engine healthy. With these tips, you’ll be ready to enjoy your boosted BRZ on the road or the track.