Installing a GTM Stage 2 Turbo Kit on your Nissan 370Z is one of the most effective ways to dramatically increase horsepower and torque. This comprehensive guide provides step-by-step instructions that cover everything from preparation to final testing, ensuring a safe and successful installation. Whether you’re an experienced DIY mechanic or a dedicated enthusiast, following these steps carefully will help you unlock the full potential of your VQ37VHR engine.

Overview of the GTM Stage 2 Turbo Kit

The GTM Stage 2 Turbo Kit is a complete forced-induction system designed specifically for the Nissan 370Z (2009+). It includes a precision turbocharger, cast exhaust manifold, intercooler, piping, and all necessary hardware to support moderate boost levels (typically 7–10 psi). With proper tuning, this kit can produce over 500 wheel horsepower on pump gas. The kit is engineered for a bolt-on installation with minimal cutting or welding, though some modifications to the factory components are still required.

Before beginning, ensure your vehicle is in good mechanical condition. Check for any existing oil leaks, cooling system issues, or worn engine components. It is also strongly recommended to upgrade your fuel system, clutch, and cooling system to handle the additional power. For more details on the kit specifications, visit the official GTM Motorsports product page.

Tools and Materials Needed

Gather all tools and components beforehand. Missing a part can cause unnecessary delays. The following list covers the essentials, though some items may vary based on your specific vehicle year and optional upgrades.

  • GTM Stage 2 Turbo Kit (includes turbocharger, manifold, intercooler, piping, gaskets, clamps, and hardware)
  • Socket set (metric 8mm to 24mm, deep and shallow)
  • Combination wrenches and ratcheting wrenches
  • Torque wrench (ft-lb and in-lb ranges)
  • Set of Allen keys and Torx bits
  • Intercooler piping (included in kit; verify before starting)
  • Engine oil (5W-30 or as recommended for your climate) and coolant (Nissan Long Life Antifreeze)
  • Vacuum lines (silicone, included or purchased separately)
  • Fuel pump upgrade (e.g., Walbro 255 or 450 LPH, if not already upgraded)
  • Additional gaskets and clamps (copper exhaust gasket, T-bolt clamps)
  • Safety gear: mechanic gloves, safety glasses, and a fire extinguisher
  • Jack and jack stands or a lift
  • Oil catch can (recommended for crankcase ventilation)
  • Heat wrap or thermal barrier coating (optional but highly beneficial)
  • Access to a professional dyno tuner or a flash-tune device (e.g., Uprev, Ecutek, or Cobb Accessport)

Note: If your 370Z has an automatic transmission, verify that the kit supports your specific model. Upgrading the transmission cooler is also advised.

Preparation Steps

Proper preparation sets the foundation for a smooth installation. Work in a well-ventilated area with ample lighting. Allow the engine to cool completely before starting.

1. Disconnect the Battery

Using a 10mm wrench, loosen the negative terminal cable and move it away from the battery post. This prevents accidental shorts and protects the ECU during electrical disconnections.

2. Drain Fluids

Drain the engine oil and coolant partially (you don’t need to remove all coolant from the system, but drain enough to avoid spills when disconnecting lines). Place drain pans under the oil pan and radiator petcock. Dispose of fluids properly.

3. Remove the Stock Intake and Exhaust

Unbolt the factory air intake box and mass airflow sensor (MAF) housing. Disconnect the intake tube from the throttle body. Next, remove the front bumper cover to access the intercooler location later. Remove the stock exhaust manifold (header) along with the catalytic converters. This is a good opportunity to inspect and replace worn oxygen sensors. Keep all bolts and brackets organized; you will reuse some for the new components.

4. Inspect and Upgrade Fuel System

The GTM Stage 2 kit typically requires higher fuel flow. If you have not already upgraded the fuel pump, now is the time. Access the pump through the access panel under the rear seat. Replace the fuel filter and ensure the fuel lines are in good condition. For higher boost levels, consider upgrading to 650cc or larger injectors. Refer to the tuning guide for injector sizing recommendations.

Turbo Kit Installation

With the engine bay clear, you can begin installing the turbo system. Follow the order below to ensure proper clearance and routing of all lines.

5. Install the Turbo Manifold

The GTM manifold is a cast piece that replaces the stock exhaust manifold. Apply a thin layer of copper anti-seize to the head studs, then position the manifold with the included gasket. Tighten the bolts in a cross-pattern sequence to the manufacturer’s specified torque (typically 35–40 ft-lb for M8 bolts). Do not overtighten, as this can warp the flange.

6. Mount the Turbocharger

Attach the turbocharger to the manifold using the provided gasket and hardware. Ensure the turbo is oriented correctly so that the oil drain faces downward and the compressor outlet aligns with the intercooler piping path. Tighten the retaining nuts evenly. Before final tightening, rotate the turbine wheel by hand to confirm it spins freely without binding.

7. Install the Intercooler

The intercooler mounts in front of the radiator, using brackets that attach to existing crash bar holes. Cut or notch the bumper support as needed for clearance. Position the intercooler and secure it with the supplied bolts. Verify that it sits straight and does not contact the radiator or air conditioning condenser.

8. Connect the Charge Piping

Route the intercooler piping from the turbo compressor outlet to the intercooler inlet, then from the intercooler outlet to the throttle body. Use silicone couplers and T-bolt clamps. Ensure each connection is clean and free of debris. Tighten clamps to 4–5 ft-lb (just enough to compress the silicone without cutting it). Double-check that piping does not rub against the chassis or steering components.

9. Install the Wastegate and Blow-Off Valve

If your kit includes an external wastegate, mount it on the manifold or specific adapter. Connect the vacuum reference line to a manifold boost source. For a BOV, install it on the cold-side piping near the throttle body. Route the vacuum line to a dedicated port on the intake manifold or a vacuum distribution block. Seal all threads with Teflon tape or silicone sealant.

10. Connect Oil and Coolant Lines

The turbocharger requires both oil and coolant circulation. Use the provided oil feed line (often a -4AN braided hose) from the oil gallery near the oil filter housing. Ensure the line does not contact hot surfaces. The oil return (drain) line must flow downhill to the oil pan; drill and tap the pan if necessary, following the supplied template. For coolant, connect the feed from a small heater hose or a dedicated port on the water pump, and route the return to the radiator or coolant reservoir. Use high-quality hose clamps and check for kinks.

11. Reinstall the Intake and Exhaust Components

Reinstall any components you removed, such as the MAF housing (now relocated to the turbo intake pipe) and the factory air ducting. If your kit replaces the catalytic converters with test pipes, install those now. Reconnect the exhaust system using new gaskets and sealant. Tighten all bolts to factory specifications.

12. Wire the Electronic Boost Controller (if applicable)

Some GTM kits include a manual or electronic boost controller. Install the controller in the cabin or engine bay according to the instructions. Connect the solenoid to a 12V switched power source and ground. Calibrate the boost level after the engine is running, following the tuner’s guidance.

Final Steps and First Start

Before starting the engine, perform a thorough check of all connections, bolts, and hoses.

13. Refill Fluids and Reconnect the Battery

Refill the engine oil with the appropriate amount and type. Add coolant, burping the system to remove air pockets. Reconnect the negative battery terminal. Ensure no tools are left in the engine bay.

14. Prime the Oil System

Disconnect the fuel pump fuse or relay, then crank the engine for 10 seconds in 3-second intervals. This allows oil to reach the turbo bearings without the engine starting. Reconnect the fuse after priming.

15. Start the Engine and Check for Leaks

Start the engine and let it idle at around 1,000 RPM for 2–3 minutes. Listen for any unusual noises from the turbo or exhaust. Check all oil, coolant, and charge pipe connections for leaks. Tighten as needed. If you see any oil dripping from the turbo drain, stop immediately and verify the drain line angle and O-ring seal.

16. Perform an Initial Test Drive and Tuning

Take the car for a short, low-boost test drive (stay below 3,000 RPM and avoid full throttle). Monitor boost pressure, engine temperature, and oil pressure. After confirming everything is stable, you must have the ECU professionally tuned. Running the engine without a proper tune can cause severe damage. Use a reputable tuner or remote tuning service that supports your flash device. For additional guidance, refer to resources like the 370Z forum for turbo tuning tips.

Post-Installation Maintenance and Tips

After the kit is installed and tuned, adopt a mindful maintenance routine.

  • Check oil levels every fuel fill-up. Turbo engines consume more oil under load.
  • Inspect charge pipe clamps monthly for loosening due to heat cycles.
  • Replace spark plugs every 15,000 miles or sooner if you experience misfires.
  • Use high-octane fuel (91 or 93) and consider a fuel additive to prevent detonation.
  • Monitor boost pressure with a quality gauge and log data during aggressive driving.

Safety Warning: Always operate turbocharged vehicles with extra caution. The increase in power can overwhelm stock braking and suspension systems. Upgrade accordingly. Never bypass or disable factory safety features such as the catalytic converters or O2 sensors for street use; it is illegal in many regions.

Conclusion

Installing a GTM Stage 2 Turbo Kit on your 370Z is a challenging but extremely rewarding project. By following this detailed guide, you can achieve a reliable, high-performance setup that transforms the driving experience. Remember that preparation, patience, and proper tuning are the keys to success. For further reading, explore the official installation manual from GTM Motorsports and discuss your build with the 370Z community. With the right approach, you’ll enjoy many miles of boosted excitement.