Installing a Precision Turbo PT6155 on a 2JZ: A Complete Step‑By‑Step Guide

The Precision Turbo PT6155 is a proven performer for the 2JZ‑GE and 2JZ‑GTE platforms, offering a broad power band and excellent response on engines built for 500–800 wheel horsepower. This guide provides a detailed, shop‑proven procedure for a safe and reliable installation. Before beginning, verify that your engine’s fuel system, cooling system, and engine management are capable of supporting the airflow the PT6155 delivers. Worn or stock fuel components should be upgraded to avoid lean conditions during boost.

Tools and Materials Needed

  • Precision Turbo PT6155 (select appropriate turbine housing AR for your power goals)
  • Wrench and socket set (metric and SAE, 6‑point preferred)
  • Torque wrench (capable of 25–80 ft‑lbs)
  • Intercooler piping kit (2.5” or 3” recommended)
  • Oil feed line (‑4 or ‑3AN) with restrictor (0.060” or 0.035” as needed)
  • Oil drain line (‑10AN minimum, with proper slope)
  • Coolant feed and return lines (if water‑cooled center section)
  • Exhaust manifold gasket and turbo mounting gasket
  • Anti‑seize compound (nickel‑based for exhaust bolts)
  • Boost controller (manual or electronic, if desired)
  • Pre‑mixed coolant and high‑quality engine oil (5W‑30 or 10W‑40 synthetic)
  • Shop rags, drain pan, safety glasses, and welding gloves
  • Threaded plugs for oil/coolant ports (if temporarily blocking)
  • Vacuum/pressure tester (for boost leak testing)

Preparation

Work on a level surface with the vehicle securely lifted or on jack stands. Disconnect the battery negative terminal. Allow the engine to cool completely if it was recently run. Drain the engine oil and coolant to prevent spills when disconnecting lines. Remove the under‑tray and any splash shields for access. This is also a good time to inspect your engine mounts and drivetrain components for wear, as the added torque may stress aging rubber mounts.

Remove the Old Turbocharger

If a turbo is already installed, removal follows standard procedure. For a naturally aspirated 2JZ‑GE conversion, you will be fabricating or purchasing a turbo manifold; skip to the installation section.

  1. Remove air intake and intercooler piping. Unbolt the intake tube from the turbo inlet and disconnect all intercooler charge pipes. Mark the orientation of silicone couplers for reinstallation.
  2. Disconnect oil feed and drain lines. Use line wrenches to avoid rounding fittings. Expect some residual oil to drip – position a drain pan beneath.
  3. Disconnect coolant lines. If the turbo is water‑cooled, pinch the lines with spring clamps and remove the hoses. Cap the block fittings to prevent debris ingress.
  4. Remove electrical connectors. Knock sensor, wastegate solenoid, and oxygen sensor wiring should be detached. Label connectors with tape.
  5. Unbolt the turbo from the manifold. Work from the centre outward using a long‑reach socket. Corroded bolts may require penetrating oil and patience.
  6. Lift the old turbo out. Rotate the assembly to clear the block and frame rails. A helper is recommended to avoid dropping the unit.

Install the Precision Turbo PT6155

Before bolting the new turbo, inspect the manifold surface for warpage or cracks. A straightedge across the mounting face will reveal any imperfections. Use a new manifold gasket – never reuse a crushed gasket.

Mounting the Turbo

  1. Lightly coat the manifold mounting studs with anti‑seize.
  2. Slide the new gasket onto the studs. Do not use sealant on paper‑style gaskets; copper spray is acceptable for multi‑layer steel gaskets.
  3. Carefully lower the PT6155 onto the studs, ensuring the turbine housing aligns with the wastegate port (if equipped).
  4. Thread on the nuts (or bolts) hand‑tight, then torque in a crossing pattern to 45–55 ft‑lbs (refer to your turbo’s spec sheet). Over‑torquing can warp the turbine housing.

Oil Feed and Drain Lines

The PT6155 uses a journal bearing or ball bearing center section depending on the version. Ball bearing units require a restrictor in the oil feed line to limit pressure to 40–60 psi at the turbo. Journal bearing turbos may run a larger restrictor or none at all; follow Precision’s guidance for your specific PN. Use a ‑4AN or ‑3AN braided line for the feed. For the drain, use a ‑10AN line that slopes downward continuously from the turbo to the oil pan. No dips or kinks. If your 2JZ pan lacks a return port, weld on a dedicated bung compatible with the drain line fitting. Apply a small amount of anti‑seize to the drain flange bolts.

Coolant Lines (If Applicable)

Water‑cooled center sections prolong seal life. Connect the coolant feed from the engine block or heater hose circuit and the return to the cooling system. Bleed air after filling coolant to avoid steam pockets. Use only fresh coolant mixed 50/50 with distilled water.

Wastegate and Boost Reference

Most PT6155 configurations come with an integrated wastegate or an external gate flange. If using an external wastegate, route a vacuum line from the compressor discharge to the top port of the gate. For internal gates, connect the actuator arm to the flapper valve. Tighten the actuator rod to achieve the desired base boost level (typically 8–12 psi). Use threadlocker on the rod threads.

Connecting the Intercooler Piping

Precision Turbo recommends 2.5” or 3” charge pipes for the PT6155. Measure and cut piping so that all bends are as smooth as possible. Avoid 90‑degree fittings directly off the compressor outlet – use a 45‑degree elbow or a mandrel‑bent pipe. Silicone couplers should overlap at least 1 inch and be secured with T‑bolt clamps torqued to 60–80 in‑lbs. Perform a clamp tightness check after initial heat cycling.

Final Checks and Reassembly

Before reconnecting the battery, go through the entire engine bay systematically:

  • Verify that all turbo mounting bolts are at spec.
  • Confirm oil and coolant lines are tight and not contacting the exhaust manifold or fans.
  • Check the turbine outlet – it should be securely attached to the downpipe with a new gasket.
  • Reinstall the intake duct, air filter, and all intercooler pipes. Ensure the filter is not in a position to ingest hot engine air.
  • Reconnect the battery. Perform a crank‑no‑start test (disable the fuel pump or ignition) to prime the oil system. Crank for 10 seconds, pause 15 seconds, then crank again. This pushes oil into the turbo bearing before startup.
  • Refill engine oil with a high‑zinc break‑in oil or your chosen synthetic. Refill coolant and bleed the system.

Boost Leak Test

Pressurize the intake system to 20–25 psi using a boost leak tester and a regulated air source. Listen for hissing at couplers, throttle shaft, injector seals, and the intake manifold gasket. Fix any leaks before starting the engine. Leaks post‑startup can cause erratic idle and lean conditions.

Testing the Installation

Start the engine and let it idle immediately. Do not rev the engine cold. Monitor oil pressure – it should climb within a few seconds. Look for oil drips under the turbo, especially around the drain flange. Let the engine reach operating temperature (about 185–200°F).

  • Check for leaks: Inspect oil, coolant, and boost lines while the engine is hot. Tighten if needed, but never over‑tighten aluminum fittings.
  • Verify boost control: With the engine idling, watch the wastegate actuator rod – it should be stationary. On a test drive, slowly increase load (4th gear, 2000–3000 rpm) and watch boost pressure. Make adjustments to the boost controller as needed.
  • Monitor air/fuel ratio: If your ECU logs wideband O2, aim for 11.5–12.0 under full boost (gasoline). Richer mixtures are safer during break‑in.
  • Perform a break‑in drive: For the first 50 miles, vary load and avoid sustained high boost. Let the turbo heat‑cycle normally. After break‑in, change the engine oil and filter.

Tuning Considerations

The PT6155 will outflow a stock turbo on a stock 2JZ‑GTE by a significant margin. You must recalibrate fuel and timing maps. A standalone ECU (AEM, Haltech, MoTeC, or a flash tune) is strongly recommended. Baseline boost at 12–15 psi with conservative timing. Increase boost in 2‑psi increments while monitoring knock retard. Many builders run 22–28 psi on E85 or race gas. Always have a professional tuner if you are not experienced.

Performance Expectations

A properly installed PT6155 on a built 2JZ (forged pistons, rods, upgraded valvetrain) can produce 650–750 whp on pump gas and north of 850 whp on ethanol. Spool is rapid, with full boost typically arriving by 3800–4200 rpm on a 2.5L to 3.0L displacement. The turbo responds well to anti‑lag and 2‑step launch control. With regular oil changes and proper cool‑down (idle 30–60 seconds after hard pulls), the PT6155 delivers long service life.

Conclusion

Installing a Precision Turbo PT6155 on a 2JZ rewards the builder with a responsive, high‑horsepower setup that can dominate street and track use. Follow this guide step‑by‑step, respect torque specs, and ensure your supporting modifications are in place. For more technical data, consult Precision Turbo’s official website for unit specs, and check Supraforums for community feedback on housing sizes and tuning maps. Always prioritise safety – high‑boost builds call for robust fuel systems, forged internals, and professional tuning.