Installing the Garrett GT35 Turbocharger on a 2JZ Engine

Upgrading to a Garrett GT35 series turbocharger is one of the most effective ways to unlock the full potential of the 2JZ engine. Known for its balance of quick spool and high horsepower capacity, the GT35 has become a staple in the performance community. This guide provides a thorough, step-by-step installation process, covering everything from initial preparation to final boost testing. Whether you are replacing a worn turbo or building a new setup, following these procedures will help ensure a reliable and high-performing installation.

Understanding the Garrett GT35 Series for 2JZ

Before diving into the installation, it is essential to understand the specific variant of the GT35 you are using. The series includes several trim options, such as the GT3582R and GT3576R, which differ in compressor and turbine wheel sizing. For a 2JZ engine, a common choice is the GT3582R with a 0.63 or 0.82 A/R housing, providing strong mid-range torque while supporting over 600 wheel horsepower. Verify that your turbo kit matches the flanges and wastegate configuration of your manifold and downpipe. Consult the Garrett performance documentation for exact specifications for your part number.

Selecting the Correct Turbo Manifold and Wastegate

The GT35 typically uses a T3 or T4 flange configuration. Most 2JZ aftermarket manifolds are designed for T3 flanges, making the GT3582R with a T3 turbine housing a direct bolt-on. Ensure your manifold has a wastegate provision. For precise boost control, an external wastegate (such as a 38mm or 44mm unit) is highly recommended. The wastegate must be plumbed into the exhaust flow before the turbine wheel to prevent boost creep. Use a quality manifold from reputable manufacturers like Full-Race or SpeedFactory to avoid cracking under high heat cycles.

Tools and Materials: A Detailed Checklist

Gathering the correct tools and hardware before starting will save hours of frustration. You will need:

  • Garrett GT35 turbocharger (complete with oil restrictor if journal bearing, or no restrictor for ball bearing)
  • Turbo manifold (T3 or T4, 2JZ-specific, with external wastegate mount if desired)
  • Downpipe (3-inch minimum, with V-band or bolt-on flange to match GT35 turbine outlet)
  • External wastegate (38–44mm) with dump tube or recirculation setup
  • Oil feed line kit (stainless braided, -3AN or -4AN, with appropriate adapter to block and turbo)
  • Oil return line kit (-10AN to -12AN, must be gravity-fed, avoid kinks)
  • Water lines (if turbo is water-cooled; use silicone hoses with clamps)
  • Intercooler core (bar-and-plate construction, rated 600+ hp)
  • Intercooler piping (2.5 to 3-inch mandrel bends, 6061 aluminum)
  • Silicone couplers (4-ply recommended, with T-bolt clamps)
  • Gaskets (manifold to head, turbo to manifold, turbo to downpipe, and wastegate flanges)
  • Copper or aluminum spray gasket sealer for exhaust joints
  • Thread sealant (PTFE or Loctite 567 for oil fittings)
  • Wrench and socket set (metric, 10–19mm, with extensions and universal joints)
  • Torque wrench (range 10–100 ft-lb for critical fasteners)
  • Oil drain tube (minimum 0.5-inch internal diameter, steel or heavy silicone)
  • Boost controller (manual or electronic, depending on setup)
  • Engine management system (standalone ECU capable of tuning for larger injectors and fuel pump)

Having all parts on hand, including new bolts and lock washers, will prevent mid-install trips to the auto parts store.

Preparation: Ready the Engine Bay

Begin by disconnecting the negative battery terminal to eliminate any risk of short circuits. Drain the engine oil completely – you will need fresh oil anyway after the install. Remove the radiator for additional clearance (optional but recommended). For a 2JZ engine, the stock radiator can be moved forward, but a slim fan setup greatly simplifies access to the turbo area.

If the engine is still factory, remove the heat shields around the exhaust manifold. Soak rusted bolts with penetrating fluid hours before to avoid shearing them. Label and bag all removed hardware.

Removing the Existing Exhaust System and Turbo

For those replacing an older turbo, follow this order:

  • Disconnect the oxygen sensor and other exhaust sensor connectors.
  • Unbolt the downpipe from the turbo and catalytic converter or midpipe.
  • Remove the entire downpipe section from the engine bay.
  • Disconnect the oil feed and return lines from the turbo. Have a drip pan ready for residual oil.
  • If water lines exist, pinch or clamp them to minimize coolant loss.
  • Unbolt the turbocharger from the exhaust manifold (typically 4 to 6 nuts).
  • Lift the turbo out vertically – watch for sharp edges on heat shields.
  • Remove the exhaust manifold itself if you are replacing it with an aftermarket unit.

Inspect the manifold studs for deformation; replace any that are damaged. Reuse only new gaskets on the manifold-to-head joint.

Step-by-Step Installation of the Garrett GT35 Turbocharger

1. Mounting the Turbo Manifold

Clean the cylinder head surface thoroughly. Apply a thin layer of copper gasket spray on the new exhaust manifold gasket. Place the manifold onto the head studs. Tighten the nuts in a crisscross pattern to the manufacturer’s torque specification (typically 33–38 ft-lb). Use high-temperature anti-seize on the threads for future removal.

2. Installing the Wastegate and Dump Tube

If using an external wastegate, mount it to the manifold’s designated flange. The wastegate opening must be located in the exhaust flow path before the turbo inlet. Use a copper gasket and tighten the mounting nuts evenly. Secure the dump tube (often routed to atmosphere or recirculated) using a V-band clamp or bolt flange. Ensure the dump tube does not contact the chassis or steering shaft.

3. Preparing the GT35 Turbo

Inspect the turbo for any shipping debris. For journal bearing GT35s, install the supplied oil restrictor (usually a 0.035–0.040 inch orifice) into the oil inlet port. Ball bearing versions do not require a restrictor if the oil pressure is under 60 psi at idle; otherwise, use a restrictor to limit flow. Rotate the compressor wheel by hand to verify free rotation.

Coat the turbine flange gasket with spray sealer. Place the turbo onto the manifold so the oil drain port faces downward and the compressor outlet aligns with your intercooler piping direction. Loosely attach the two or four bolts securing the turbo to the manifold. Once aligned, torque them to the specified value (typically 25–35 ft-lb for 303 stainless). Do not overtighten – it can distort the turbine housing.

4. Connecting Oil Feed and Return Lines

The 2JZ engine has an oil pressure port on the front of the block near the timing cover (for VVTi engines, use the port near the oil filter housing). Install an adapter fitting (often M12x1.25 or 1/8 NPT) and connect the oil feed line. Use thread sealant on NPT fittings; avoid PTFE tape that can shred and clog the oil passages.

The oil return line requires a port on the oil pan. If your pan does not have one, you must remove the pan and weld or thread a -10AN bulkhead fitting. The return line must slope downward continuously – no dips or loops – to allow gravity drainage. Use a steel or braided -10AN hose for the return.

For water cooling, most GT35s have 1/8 NPT ports. Connect heater hose or silicone lines from the block’s water circulation ports. In many 2JZ builds, water cooling is optional, but it extends turbo longevity under high heat.

5. Securing the Downpipe

Align the downpipe to the turbo’s turbine outlet flange. Use a new gasket or, for V-band connections, clean the sealing faces. Tighten fasteners evenly. Support the downpipe with a bracket to the bellhousing or engine block to prevent stress on the turbo exhaust housing.

Intercooler and Charge Piping Installation

An efficient intercooler is critical for reducing intake temperatures. Choose a core that fits your bumper opening and supports your horsepower target. For a 600+ whp 2JZ, a 3-inch thick, 24-inch wide core is typical.

  • Mount the intercooler using brackets or straps that isolate it from chassis vibration.
  • Route the hot side pipe from the GT35 compressor outlet to the intercooler inlet. Use mandrel bends and silicon couplers with T-bolt clamps to prevent blow-off.
  • Route the cold side pipe from the intercooler outlet to the throttle body. Add a blow-off valve (BOV) near the throttle body – a 50mm unit such as a Synapse or Turbosmart is recommended.
  • Ensure all pipe sections are secured with clamps and brackets; do not let them rest on moving parts.

Important: use silicone couplers with a minimum of 4 ply layers to withstand 25+ psi of boost. Secure all connections with T-bolt clamps instead of worm-gear clamps to prevent leaks at high pressure.

Boost Control and Wastegate Plumbing

For an external wastegate, install the boost controller in the hose between the compressor housing boost reference port and the wastegate’s top port. Many tuners recommend a Turbosmart Hypergate for consistent pressure control. The wastegate spring pressure (typically 7–14 psi) will be the base boost level when no boost controller is used or when the controller is fully open.

Use high-temperature silicone hoses for all vacuum lines. Avoid push-lock fittings near hot exhaust; premium barb fitting with hose clamps work best. Test the wastegate operation before startup.

Electrical and Sensor Connections

Reconnect the oxygen sensor in the downpipe (or wideband O2 sensor bung, which should be positioned before the catalytic converter). If using a boost controller, wire the solenoid to a 12V switched power source and to the ECU or manual controller interface. Ensure the MAF sensor (if retained) is placed on a straight section of intake piping, at least 12 inches from the turbo inlet. Many 2JZ turbo builds switch to a MAP-based speed density system for cleaner airflow. Refer to Haltech’s 2JZ tuning guide for sensor placement recommendations.

Final Assembly and Fluid Fill

Reinstall any components removed for access: radiator, fans, intercooler shrouds, and bumper cover. Double-check the oil drain line is not kinked or overly long. Fill the engine with premium engine oil – 10W40 synthetic is common for turbo 2JZ engines. Fill the coolant system if water lines are used. Reconnect the battery and prime the oil system: unplug the fuel pump relay, crank the engine for 15 seconds in bursts until oil pressure registers on the gauge, then plug the relay back.

Pre-Start Leak Inspection

With the engine running at idle, inspect all exhaust joints for smoke or black soot. Listen for air hissing from charge pipes – apply soapy water to couplers if needed. Check the oil feed threads and return line for wet spots. Monitor oil pressure; should be above 10 psi at idle when warm. Let the engine reach operating temperature to verify cooling system bleed.

Testing the Installation: Road and Boost Validation

Begin with a short, gentle drive avoiding wide-open throttle. Let the turbo heat cycle and check for any new noises. After 10–15 minutes of low boost driving, perform a more aggressive pull to verify boost response.

  • Monitor boost pressure via a gauge or ECU logging. The GT35 should hit full boost by 3500–4000 rpm on a 2JZ if properly matched.
  • Watch for boost creep: if boost exceeds the wastegate spring setting, the wastegate may be undersized or the exhaust flow is misdirected.
  • Listen for compressor surge – a fluttering sound during throttle lift – which indicates the BOV is insufficient or improperly located.
  • After the test drive, re-torque the downpipe and manifold nuts once the engine is cool. Heat cycles can loosen fasteners.

Troubleshooting Common GT35 Installation Issues

Oil Leaks at Turbo Inlet or Return

If you see oil at the compressor housing, the turbo seal may be damaged, but more often the oil return line is partially blocked or the turbo sits too high, preventing proper drain. Ensure the return line is free and the port in the oil pan is at least 0.5 inches above the oil level. For engines with high crankcase pressure, install a proper crankcase ventilation system.

Boost Creep or Slow Spool

Slow spool may be caused by an oversized turbine housing. If using a 0.82 A/R housing on a stock engine, consider switching to a 0.63 A/R. Boost creep usually results from insufficient wastegate flow. A 44mm wastegate with a dedicated dump tube or a larger wastegate port in the manifold will resolve it.

Exhaust Leaks Between Manifold and Turbo

This is often due to warped flanges or improper gasket use. Always use a new gasket and ensure both turbo and manifold flanges are flat. A small amount of copper spray can help seal minor imperfections.

To fully realize the GT35’s potential on a 2JZ, the following upgrades are strongly advised:

  • Larger fuel injectors (1000cc or more) and a 255 lph or higher fuel pump
  • Standalone ECU – options include Motec M1, Haltech Nexus, or Link G4+ for precise fueling and ignition control
  • Upgraded valve springs and retainers (dual springs for engines revving above 7500 rpm)
  • Upgraded head studs (ARP 2000 or L19) to handle increased cylinder pressure
  • Stronger drive train – a 2JZ with GT35 can exceed 600 whp, so consider a built automatic transmission or upgraded manual clutch.

For track-focused builds, a Garrett GTX3584R may deliver even higher efficiency with minimal spool penalty.

Conclusion

Installing a Garrett GT35 turbocharger on a 2JZ engine is a rewarding project that dramatically elevates the car’s performance. Through careful preparation, precise mechanical work, and thorough testing, the GT35 provides a broad power band and proven reliability. Always consult the manufacturer’s specifications for torque values and clearances, and never skip the test drive validation. With the right supporting modifications and a quality tune, your 2JZ will deliver an exhilarating driving experience that remains safe and consistent for years.