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Lexus GS300 Turbo Build Part 3 | CXRacing GT35 Install and First Start
September 19, 2026 Daniel Ho

Lexus GS300 Turbo Build Part 3 | CXRacing GT35 Install and First Start

We're back with Part 3 of our Lexus GS300 Turbo Build Series, and this is one of our biggest milestones yet. We're finally installing the CXRacing GT35 turbo kit on our 2JZ-GE VVT-i engine and attempting our first startup!

In the previous episodes, we upgraded our fuel system, installed larger injectors, and prepared our engine for forced induction. We also installed a Panic Made engine wiring harness, Link G4X standalone ECU, and adjustable fuel pressure regulator.

Now it's time to put everything together. We're installing the turbo oil feed and return lines, front mount intercooler, charge piping, blow-off valve, external wastegate, boost controller, oil catch can, and downpipe. We'll also calibrate our ECU, set the base fuel pressure, and see if our turbocharged GS300 will finally start.

If you're planning a 1998–2005 Lexus GS300 2JZ-GE NA-T conversion, follow along as we show you the installation process, fitment challenges, and modifications needed to get our car running.

Parts Used in Our Lexus GS300 Turbo Build

Our turbocharger setup is based around the CXRacing GT35 Turbo Kit for the 1998–2005 Lexus GS300 2JZ-GE VVT-i. This kit includes the major turbocharger hardware needed for our NA-T conversion, including the turbocharger, manifold, intercooler system, downpipe, wastegate, blow-off valve, and oil line hardware.

Step 1: Removing the Oil Pan for the Turbo Oil Return

Our first major task was creating an oil return connection for the turbocharger.

Because the factory 2JZ-GE is naturally aspirated, we needed to add a suitable oil drain connection to the engine.

We decided to install a threaded fitting into the upper oil pan, allowing the oil returning from the turbocharger to drain back into the engine.

Accessing the Oil Pan Bolts

Removing the lower oil pan was more difficult than we expected.

Several bolts toward the rear of the pan were extremely difficult to reach with the engine sitting in its factory position.

We removed the oil filter, loosened the engine mounts, and carefully raised the engine slightly to create more working room.

After gaining access to the rear bolts, we were finally able to remove the lower oil pan.

If you're working on a similar project, check out our Engine Accessories & Performance Parts Collection for related engine components and upgrades.

Removing the Oil Baffle and Pickup

With the lower oil pan removed, we could access the upper oil pan where we planned to install our turbo oil return fitting.

We removed the internal baffle and oil pickup assembly to gain better access to the area we needed to drill.

This also allowed us to better control metal debris during the modification.

Metal shavings inside the oil pan can contaminate the lubrication system, so removing and thoroughly cleaning the affected components is essential.

Drilling and Tapping the Turbo Oil Return

After locating the intended oil return position, we moved a nearby water neck out of the way and prepared the area for drilling.

We drilled and tapped the opening while using a vacuum to help collect metal shavings.

For our setup, we used a 1/8-inch NPT fitting transitioning to a -10 AN oil drain connection.

After installing the fitting with appropriate thread sealant, we reassembled the oil pickup, baffle, and lower oil pan.

Important Note: The oil return configuration shown in our video is specific to our build. Turbocharger oil return sizing, placement, and fitting selection should follow the turbocharger manufacturer's requirements. All metal debris must be removed before reassembly.

Step 2: Installing the CXRacing Front Mount Intercooler

Next, we moved on to installing the front mount intercooler included with our CXRacing GT35 Turbo & Intercooler Kit.

The intercooler helps reduce the temperature of compressed intake air before it enters the engine, making it an important component of our turbocharged 2JZ-GE setup.

Removing the Factory Shroud and Horn Brackets

We started by removing the factory shroud and hardware that interfered with the intercooler installation.

One of the biggest fitment issues involved the factory horns.

The intercooler brackets occupied part of the original horn mounting area, so we removed and repositioned components to create additional clearance.

We also removed an interfering factory bracket to make room for the intercooler.

Mounting the Intercooler with Rivet Nuts

After positioning the intercooler, we installed rivet nuts into existing chassis holes to create mounting points for the lower support brackets.

This allowed us to secure the intercooler without needing to hold nuts behind the mounting locations.

We then checked the fitment around the air-conditioning components and surrounding chassis.

For additional charge-air components, browse our CXRacing Performance Parts Collection, which includes intercooler systems, turbo piping, and related hardware.

Step 3: Installing and Clocking the GT35 Turbocharger

With the intercooler in position, we moved on to the turbo manifold and GT35 turbocharger.

We initially left the components loosely mounted so we could determine the best turbocharger orientation and intercooler piping route.

Using Studs for Easier Manifold Installation

Some of the turbo manifold mounting bolts were difficult to access because of the limited space around the engine.

To make installation easier, we replaced some of the bolts with studs.

This made it easier to position the manifold and install the remaining mounting hardware.

What Does Clocking a Turbocharger Mean?

Clocking a turbocharger involves rotating its housings to achieve the required compressor outlet and oil connection orientation.

We loosened the housing hardware and adjusted the turbocharger so the compressor outlet would line up with our intercooler piping.

We also wanted the oil feed positioned near the top and the oil drain directed downward.

After several adjustments, we found an orientation that worked with the available space in the GS300 engine bay.

Turbo Installation Tip: Always verify the center housing and oil drain orientation against the turbocharger manufacturer's specifications. Incorrect oil drainage can cause oil backup and turbocharger problems.

Our exact turbocharger setup is available through Lunatics Company: CXRacing GT35 Turbo Kit for Lexus GS300 NA-T Conversions.

Step 4: Routing the Intercooler Piping

Once the turbocharger was loosely positioned, we started routing the charge piping.

We worked through the piping sections one at a time, checking how everything would fit around the headlight, radiator, air-conditioning components, and other engine bay hardware.

The charge piping runs from the turbocharger, underneath the headlight area, into the front mount intercooler, and back toward the throttle body.

After confirming the piping layout, we returned to the turbocharger and finalized its position.

Proper pipe alignment is important for reducing stress on silicone couplers and helping prevent boost leaks.

If you're building your own GS300 turbo setup, our Lexus GS300 Performance Parts Collection includes compatible turbocharger and performance options. Always verify engine and chassis fitment before ordering.

Step 5: Installing the Turbo Oil Feed Line

Next, we installed the oil filter sandwich adapter to create an oil supply connection for the turbocharger.

The adapter mounts at the oil filter location and provides threaded ports for compatible oil connections.

We selected one port for the turbocharger oil feed and plugged the unused port.

We then routed the oil feed line toward the turbocharger, checking the available clearance around the engine.

The correct oil feed line size, pressure, and any required restrictor depend on the specific turbocharger.

For related engine components, visit our Engine Accessories Collection.

Step 6: Building the Custom -10 AN Turbo Oil Drain

For the turbo oil return, we decided to use a custom -10 AN drain arrangement rather than the fitting originally included with the kit.

We installed a separate drain flange and worked on creating a line that would reach the fitting added to the upper oil pan.

Modifying the Drain Fitting for Clearance

During the mockup, we discovered that the drain fitting needed a small clearance adjustment.

We carefully removed a small amount of material from the interfering area so the fitting could sit in the desired orientation.

After confirming the fitment, we installed the drain flange with its gasket and mounting hardware.

Routing the Drain Line Around the Alternator

We also needed to route the drain line around the alternator and nearby radiator hose.

After trying several fitting combinations, we found an angled adapter that made the connection easier to assemble.

We finalized the line length and positioned the drain connection so it could be installed without repeatedly removing the turbocharger.

The completed drain system needs to maintain adequate oil flow without restrictions, kinks, or contact with hot and moving components.

Step 7: Installing the Blow-Off Valve

With the turbocharger and intercooler piping positioned, we installed the blow-off valve included with our setup.

The blow-off valve releases excess charge pressure when the throttle closes under the appropriate operating conditions.

We mounted the valve to the charge piping and routed its pressure reference hose to the intake manifold.

For other turbocharger components and accessories, explore our CXRacing Turbo & Performance Parts.

Step 8: Installing the Wastegate and Boost Controller

Next, we moved on to the external wastegate and boost controller.

The wastegate regulates exhaust flow through the turbocharger, while the boost controller adjusts the pressure signals used to operate the wastegate.

Changing the Wastegate Spring Configuration

Our wastegate originally contained multiple springs that we believed provided approximately 8 PSI of combined spring pressure.

We removed one spring with the intention of reducing the mechanical boost pressure to approximately 4 PSI for our initial setup.

We then reassembled the wastegate and prepared it for installation.

Important Note: Wastegate spring pressure must be confirmed using the manufacturer's specifications or appropriate testing. Removing a spring does not guarantee a specific boost pressure.

Mounting the Boost Controller

We tested several mounting locations before choosing a position inside the engine bay.

Once mounted, we routed the pressure lines between the turbocharger, controller, and wastegate.

Our setup uses a T-fitting with connections routed to the upper and lower wastegate ports according to our controller arrangement.

Before driving under boost, the plumbing and controller settings need to be verified against the manufacturer's instructions.

Step 9: Installing the Oil Catch Can

With the turbocharger plumbing nearly finished, we installed an aftermarket oil catch can.

Our initial setup uses hoses connected to the valve cover breather ports and routes them toward a catch can mounted near the battery.

We selected a vent-to-atmosphere configuration for this stage of the build.

Finding a Mounting Location

Space was becoming limited with the turbocharger, intercooler piping, battery, and other supporting components installed.

We eventually found a location near the battery and secured the catch can using its supplied bracket.

We then routed the hoses from the valve covers toward the catch can.

Checking Hose and Fitting Sizes

One issue was that the valve cover connections and catch can fittings weren't all the same size.

We mocked up the system, but mismatched or overstretched hoses should be replaced with correctly sized fittings before normal operation.

We may eventually upgrade to a cleaner catch can setup as we continue improving the engine bay.

Browse our Engine Accessories & Supporting Modifications for additional engine-related upgrades.

Step 10: Installing the Downpipe and Heat Protection

With the turbocharger and oil lines installed, we moved on to the downpipe.

We wrapped the downpipe with exhaust heat wrap to help manage heat around nearby components.

We also added heat protection to the wastegate dump pipe and installed protective sleeving around a nearby coolant hose.

Heat management is especially important on this setup because the turbocharger and downpipe sit close to other components in the engine bay.

Heat wrap and sleeving can help, but proper clearance and secure mounting are still necessary.

Installing the Wideband and Intake Air Temperature Sensors

We also had sensor bungs welded into the downpipe and charge piping.

The wideband oxygen sensor was installed into the downpipe and connected to our Link CAN Lambda Wideband System.

The intake air temperature sensor was installed in the charge piping so the ECU could monitor intake air temperatures.

We then routed and organized the remaining wiring around the engine bay.

Step 11: Preparing the Lexus GS300 for Its First Startup

After multiple episodes of preparation, we were finally getting close to starting our turbocharged 2JZ-GE.

Before attempting the startup, we needed to refill the required fluids, inspect the fuel and oil systems, and complete the ECU calibrations.

Calibrating the Link G4X ECU

We're using a Link G4X standalone ECU paired with a Panic Made Full Engine Wiring Harness.

Using the ECU software, we opened the throttle calibration settings and followed the prompts.

We then calibrated the accelerator pedal position sensor by following the instructions to press and release the pedal.

These calibrations help the ECU interpret the throttle and accelerator pedal signals correctly.

The Panic Made Lexus IS/GS Full Engine Harness & G4X ECU Package is an option for compatible manual-transmission Lexus applications. Automatic-transmission compatibility should not be assumed.

Building Oil Pressure Before Startup

Before starting the engine, we disconnected the fuel pump and cranked the engine to begin building oil pressure.

This was especially important because we had modified the oiling system and installed new turbocharger oil lines.

We also checked for leaks during the initial cranking attempts.

Step 12: First Start of Our Turbocharged Lexus GS300!

After completing the necessary preparations, it was finally time to start the engine.

We cranked the car, and after all the work involved in the fuel system, engine wiring, and turbocharger installation, the engine finally fired up!

This was a huge milestone for the build.

Our naturally aspirated 2JZ-GE had officially reached its first startup with the turbocharger hardware installed.

We checked the engine bay for leaks and continued monitoring the setup while preparing to adjust the fuel pressure.

Setting the Base Fuel Pressure

After the engine started, we adjusted the fuel pressure regulator.

For our particular setup, we disconnected the regulator's vacuum reference hose and temporarily capped the manifold connection to prevent a vacuum leak.

We then adjusted the regulator while monitoring the fuel pressure gauge.

Our target base fuel pressure was approximately 43.5–44 PSI.

Once the pressure was adjusted, we secured the regulator setting and prepared to reconnect the pressure reference.

Fuel Pressure Note: This was the base fuel pressure selected for our build, not a universal specification. The correct pressure depends on the injectors, regulator, fuel system, and ECU calibration.

What We Accomplished in Lexus GS300 Turbo Build Part 3

  • Removed the lower oil pan to access the upper pan.
  • Drilled and tapped the turbo oil return connection.
  • Installed a custom -10 AN turbo oil drain line.
  • Installed the oil filter sandwich adapter and turbo oil feed line.
  • Mounted the CXRacing front mount intercooler.
  • Modified the horn and bracket locations for intercooler clearance.
  • Installed and clocked the GT35 turbocharger.
  • Routed the intercooler piping.
  • Installed the blow-off valve and manifold reference hose.
  • Configured the wastegate springs and boost controller plumbing.
  • Installed an aftermarket oil catch can.
  • Installed the downpipe and added heat protection.
  • Connected the wideband and intake air temperature sensors.
  • Calibrated the throttle and accelerator pedal sensors.
  • Adjusted the base fuel pressure to approximately 43.5–44 PSI.
  • Successfully started the turbocharged 2JZ-GE engine.

We still have more work ahead of us, but getting the engine running was a major achievement.

Frequently Asked Questions About Turbocharging a Lexus GS300

Can you turbocharge a stock Lexus GS300 2JZ-GE?

Yes. The naturally aspirated 2JZ-GE can be converted to a turbocharged NA-T configuration. Engine condition, fuel delivery, engine management, tuning, and supporting modifications are critical for reliability.

What turbo kit did you install on the GS300?

We installed the CXRacing GT35 Turbo & Front Mount Intercooler Kit for the 1998–2005 Lexus GS300 2JZ-GE VVT-i.

Where does the turbo oil return connect on a 2JZ-GE?

Our build uses a modified upper oil pan with a threaded fitting connected to a custom -10 AN oil drain line. Proper drain location, fitting size, and routing must be verified for the specific turbocharger and engine setup.

Why is turbo clocking important?

Clocking positions the turbocharger housings so the compressor outlet aligns with the charge piping while the center housing maintains a suitable oil feed and drain orientation.

What boost pressure are you running?

We changed the wastegate spring arrangement with the intention of lowering mechanical boost pressure to approximately 4 PSI. Actual boost pressure had not yet been verified during a driving or tuning session in this episode.

What ECU are you using for the GS300 turbo build?

We're using a Link G4X standalone ECU with a Panic Made Full Engine Wiring Harness.

What base fuel pressure did you set?

For our setup, we adjusted the regulator to approximately 43.5–44 PSI with the vacuum reference disconnected and the manifold port capped. This is our build's setting, not a universal requirement for every turbocharged GS300.

Did the turbocharged Lexus GS300 start successfully?

Yes! After installing the turbocharger hardware, completing ECU calibrations, and checking the fuel and oil systems, our GS300 successfully started for the first time with the NA-T setup.

What's Next? Lexus GS300 Turbo Build Part 4

Now that our turbocharged GS300 is running, the next step is getting everything ready for the dyno.

We still need to finish additional supporting components, install the remaining gauges, and work on the exhaust system.

After that, we'll be taking the car to the tuner to dial in the Link G4X ECU and see how our 2JZ-GE turbo setup performs.

Stay tuned for Part 4 of our Lexus GS300 Turbo Build Series!

Shop Lexus GS300 Turbo Parts at Lunatics Company

At Lunatics Company, we're enthusiasts helping enthusiasts build better Lexus and Toyota performance cars.

If you're planning your own 2JZ-GE NA-T conversion, explore the products and collections below:

Engine Management Partner: Visit Panic Made's Lexus IS/GS Full Engine Harness & Link G4X ECU Package and their Link CAN Lambda Wideband System for compatible standalone engine management components.

Visit LunaticsCo.com for Lexus and Toyota performance parts, installation content, and more GS300 build updates.

Important: Turbocharger and emissions-related modifications may be restricted to off-road or competition use. Follow applicable regulations and have modified fuel, electrical, cooling, and engine management systems inspected and tested before operation.

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