The Mitsubishi TD04L-13T Turbo Upgrade for the G70: A Complete Performance Guide

Upgrading the turbocharger on a Genesis G70 is one of the most effective ways to unlock significant horsepower gains and transform the car’s personality. Among the many turbo options available, the Mitsubishi TD04L-13T has emerged as a favorite among enthusiasts who want a substantial power increase without sacrificing daily drivability. This upgrade occupies a sweet spot—it delivers strong mid-range torque, maintains quick spool characteristics, and works with the G70’s existing engine management system when properly tuned.

This guide covers everything you need to know about fitting the TD04L-13T to your G70: how it compares to other turbo options, a detailed walkthrough of the installation, the supporting modifications you will need, tuning strategies, and realistic power expectations. Whether you are planning the upgrade yourself or working with a shop, this article provides the technical context to make informed decisions.

Understanding the TD04L-13T Turbocharger

Mitsubishi Heavy Industries has been manufacturing the TD04 family of turbochargers for decades. Originally found on Subaru WRXs, Mitsubishi Evos, and various European applications, the TD04L-13T is a twin-scroll capable unit that features a 49mm compressor wheel and a 44mm turbine wheel. The “13T” designation refers to the specific compressor trim, which flows roughly 36 lb/min of air—enough to support around 350 to 400 wheel horsepower on a properly fueled four-cylinder engine.

One of the key reasons the TD04L-13T works so well on the G70’s 2.0-liter Theta II engine is its spool characteristics. The turbine housing A/R ratio is designed to build boost quickly, often reaching 15 psi by 2800 RPM. This means minimal lag compared to larger frame turbos like a Garrett GTX2867R or a BorgWarner EFR 6258. For a street-driven car, that early torque makes a noticeable difference in daily traffic and on back roads.

The turbocharger itself is journal bearing, not ball bearing, which makes it more affordable to purchase and rebuild. While ball bearing turbos spool slightly faster and offer better transient response, the TD04L-13T is proven to handle sustained high boost levels reliably when oil feed and drain lines are properly set up. It is a robust unit that can tolerate some abuse, making it a strong choice for a weekend track car or a daily driver that sees occasional hard pulls.

Why Choose the TD04L-13T for Your G70

The G70 came from the factory with either a 2.0-liter turbocharged four-cylinder or a 3.3-liter twin-turbo V6. For owners of the 2.0T model, the stock turbo is a small, low-boost unit designed primarily for fuel economy and smooth power delivery. Peak boost hovers around 12 psi, and the compressor runs out of steam above 5500 RPM. Upgrading to the TD04L-13T addresses those shortcomings directly.

Horsepower gains are substantial. With only a tune and the turbo swap, most G70 owners report gains of 60 to 80 wheel horsepower over stock. That jump transforms the car from a competent daily driver into a genuinely quick machine. More importantly, the power curve shifts: instead of falling flat at high RPM, the TD04L-13T holds boost to redline, giving you usable power across the entire rev range.

Throttle response also improves noticeably. The stock turbo has a small, restrictive compressor housing that creates a bottleneck. Replacing it with the TD04L-13T allows the engine to breathe more freely. Tip-in response sharpens, and the car feels more eager to accelerate from any speed. This is not the kind of upgrade that only shows gains on a dyno; you feel it every time you press the pedal.

Reliability is another strong point. The Theta II engine is capable of handling more power than the stock turbo can deliver, so the TD04L-13T does not stress the bottom end beyond its limits—provided you keep boost levels reasonable and maintain proper fueling. Many enthusiasts run these setups for tens of thousands of miles without issues if they follow good maintenance practices.

Comparing the TD04L-13T to Other Turbo Options

Before you make a purchase decision, it helps to understand how the TD04L-13T stacks up against the other common upgrades for the G70 and similar Theta II applications.

Stock G70 Turbocharger

The factory turbo is a tiny Mitsubishi TD025 or similar small-frame unit. It is optimized for quick spool and low-end torque but runs out of airflow capacity around 230-250 wheel horsepower. If you try to push it beyond that range with aggressive tuning, you will overspeed the compressor wheel, generate excessive heat, and risk damaging the turbo.

TD04L-13T (This Upgrade)

This turbo represents a roughly 30% increase in airflow capacity over stock. It spools almost as quickly as the factory turbo but supports 330-380 wheel horsepower on pump gas with proper supporting modifications. It is a direct bolt-on in most cases when paired with the right oil and coolant lines. You do not need to modify the exhaust manifold or downpipe flange if you use the correct adapter or housing.

Garrett GTX2867R

This is a popular ball bearing upgrade that can support up to 450 wheel horsepower. It spools slightly faster than the TD04L-13T and offers better transient response. However, it is more expensive (typically double the cost), and it requires more extensive supporting modifications such as upgraded fuel system components and a larger intercooler. For most G70 owners, the GTX2867R is overkill unless you are building a dedicated track car or chasing high dyno numbers.

BorgWarner EFR 6258

The EFR series is the premium option. It uses a dual ball bearing cartridge, an integrated recirculation valve, and a titanium-aluminide turbine wheel for excellent durability. The EFR 6258 spools faster than any of the other options listed here and flows well over 400 wheel horsepower. But the cost is substantial, and you will need custom fabrication for the downpipe and charge piping. For a street car, the EFR is typically more than most drivers can fully exploit.

For the majority of G70 owners, the TD04L-13T delivers the best balance of cost, power, and simplicity. It is a proven platform that countless Theta II owners have used successfully.

Installation Process: A Step-by-Step Walkthrough

Installing the TD04L-13T on a G70 is a project you can complete in a weekend if you have basic mechanical skills and a reasonable set of tools. Working on a cold engine is mandatory. Disconnect the battery negative terminal before you start for safety. Here is a detailed guide.

Required Tools and Parts

  • Socket set with 10mm, 12mm, 14mm, 17mm, and 19mm sockets
  • Wrench set, combination wrenches for hard-to-reach fasteners
  • Torque wrench (ft-lb and in-lb ranges)
  • Pickle fork or ball joint separator for exhaust components
  • New gasket set: turbo-to-manifold gasket, downpipe gasket, oil return gasket
  • TD04L-13T turbocharger with compatible compressor housing clocking
  • Oil feed and drain line kit (use a banjo bolt setup with restrictor if specified)
  • Coolant lines (if your G70 uses water-cooled turbo)
  • New exhaust manifold studs and nuts if the originals are corroded
  • Anti-seize compound and high-temp silicone gasket maker

Step 1: Prepare the Work Area

Park the car on a level surface and allow the engine to cool completely. Raising the front of the car on jack stands provides better access to the underside. Remove the engine under-tray and any plastic shrouding that blocks access to the turbo area.

Drain the engine oil and coolant if you are replacing the oil and water lines. Even if you plan to reuse them, draining prevents spills during disconnection.

Step 2: Remove Intake and Exhaust Components

Remove the intake air duct from the air filter housing to the turbo inlet. Unclip the mass airflow sensor connector and set the duct aside. Disconnect the intercooler charge pipe from the turbo outlet. If your G70 has a recirculation valve hose, disconnect it as well.

On the exhaust side, unbolt the downpipe from the turbo outlet flange. These fasteners are often corroded. Apply penetrating oil several hours in advance if possible. Once the downpipe is free, remove the oxygen sensors carefully to avoid damaging the wires.

Step 3: Disconnect the Stock Turbo

Remove the heat shield over the turbo and exhaust manifold. You may need to remove the intercooler pipe bracket that mounts to the block. Disconnect the oil feed line at the turbo. Use a flare nut wrench if the fitting is a banjo bolt to avoid rounding it.

Remove the oil drain line from the bottom of the turbo. This is typically secured with two small bolts. Allow any residual oil to drain into a catch pan.

Unbolt the coolant lines at the turbo if equipped. Cap the connections on the engine side to prevent debris from entering.

Finally, unbolt the turbo from the exhaust manifold. There are usually four nuts or studs. Support the turbo as you remove the last nut to avoid dropping it. Carefully lift the turbo out of the engine bay.

Step 4: Prepare for the New Turbo

Clean the exhaust manifold mounting face thoroughly with a wire brush. Remove any remnants of the old gasket. Inspect the manifold studs and replace any that are stripped or damaged. Apply anti-seize to the new studs.

Install new gaskets on the manifold mounting face. Apply a thin coat of high-temp silicone to the gasket to help seal it.

Prepare the TD04L-13T by clocking the compressor housing to match your charge pipe routing. Most G70 applications work best with the compressor outlet pointing slightly upward and toward the front of the engine. Loosen the compressor housing retaining bolt, rotate the housing, and retighten. Do not overtighten as you can crack the housing.

Step 5: Install the TD04L-13T

Carefully position the new turbo on the exhaust manifold studs. Use a lifting strap or have a helper support it while you start the nuts. Tighten the mounting nuts in a cross pattern to 30-35 ft-lb. Do not exceed this torque value as you can distort the manifold flange.

Attach the oil feed line. If your TD04L-13T uses a journal bearing center section, you may need a restrictor in the feed line to limit oil pressure to 40-50 psi at idle. Too much oil pressure can overwhelm the seals. Consult the turbo supplier for the correct restrictor size.

Connect the oil drain line. The drain line must slope downward continuously to allow gravity to return oil to the pan. If the drain line has any low spots, oil can pool and cause smoking issues.

Attach the coolant lines. Torque banjo bolts to 20-25 ft-lb. Replace copper washers if they are crushed or damaged.

Step 6: Reassemble the Intake and Exhaust Systems

Install the new downpipe gasket and reconnect the downpipe. Tighten the downpipe nuts to 30 ft-lb. Reattach the oxygen sensors.

Reconnect the charge pipe from the turbo outlet to the intercooler. Ensure the silicone couplers are fully seated and the clamps are tight.

Reinstall the intake ducting and air filter. Double-check all vacuum lines and electrical connectors that were moved during disassembly.

Step 7: Initial Start-Up and Check

Before starting the engine, prime the turbo with oil. You can do this by disconnecting the fuel pump fuse and cranking the engine for 10-15 seconds. Alternatively, pour a small amount of oil into the turbo oil feed port before connecting the line.

Reconnect the battery. Start the engine and allow it to idle. Listen for any unusual noises such as scraping or whining. Check all connections for oil leaks. Let the engine reach operating temperature, then perform a gentle boost leak test by revving the engine to 2500-3000 RPM and listening for any air rushing sounds from loose connections.

Shut the engine off and recheck the oil level. Top off as needed.

Tuning and Calibration Requirements

Installing the turbo is only half the project. The G70’s factory ECU will not respond correctly to the increased airflow without recalibration. Running the TD04L-13T on the stock tune will cause lean conditions, knock, and potential engine damage.

ECU Remapping Options

For the G70 2.0T, the most common approach is a piggyback tuning solution or a full ECU flash via a company like Lap3, JB4, or using a standalone ECU like an AEM Infinity or Haltech Elite. Lap3 offers a specific calibration for the TD04L-13T when combined with appropriate supporting modifications. The JB4 is a popular choice because it allows you to adjust boost levels on the fly and log data without permanently altering the factory ECU.

If you opt for a full standalone ECU, you gain complete control over fueling, ignition timing, boost control, and cam timing. This approach yields the best results but requires professional tuning on a dynamometer. Expect to spend $800 to $1500 on the standalone ECU plus tuning time.

Boost Targets and Fuel Requirements

On 93 octane pump gas, a safe boost target for the TD04L-13T is 18-20 psi. At this level, the turbo operates efficiently, and the engine’s direct injection system can provide sufficient fuel. If you have access to ethanol blends like E30 or E85, you can push boost to 24-25 psi without exceeding the fuel system’s capacity. At these levels, expect 350-380 wheel horsepower on a dyno.

Boost control can be handled by the factory wastegate solenoid if you have a tune that supports it. For higher boost levels, consider an aftermarket boost controller. A manual boost controller is inexpensive and works well, but it does not compensate for changing conditions. An electronic boost controller like a boost solenoid from Turbosmart or MAC allows the ECU to target specific boost levels based on RPM and load.

Monitoring and Safety

Install an air-fuel ratio gauge with a wideband oxygen sensor. This is the single most important tool for tuning safety. You also need a boost gauge and an exhaust gas temperature gauge. EGTs should stay below 1600°F under full load. Above that, you are at risk of melting pistons or damaging the turbine wheel.

If you are not comfortable tuning the car yourself, hire a professional who has experience with the Theta II engine and Mitsubishi-based turbo swaps. A good tuner can extract maximum power while keeping the engine safe.

Supporting Modifications for a Complete Build

A turbo upgrade alone will not reach its full potential without supporting modifications. The fuel system, intake, exhaust, and intercooler all play a role in delivering the air and fuel the engine needs to make power.

Fuel System Upgrades

The G70 2.0T uses direct injection, which limits fuel capacity compared to port injection setups. At power levels above 350 wheel horsepower, the factory high-pressure fuel pump can run out of capacity. Upgrading to a high-pressure fuel pump (HPFP) from companies like HPFP Upgrade or Lap3 is recommended if you plan to run ethanol or push high boost.

For most owners staying on pump gas at 18-20 psi, the stock fuel system is adequate. But if you ever plan to go further, plan the fuel system upgrade now. It is more efficient to install it during the turbo swap than to go back later.

Air Intake and Intercooler

A larger intercooler is strongly recommended. The stock intercooler becomes a heat sink under sustained boost. Replacing it with a front-mount intercooler that has a larger core volume keeps intake air temperatures in check. This directly translates to more consistent power and less timing retard.

An aftermarket intake with a larger filter and smoother piping reduces restriction. The stock intake is silencer-heavy and restrictive. A short-ram or cold-air intake designed for the G70 will free up a few horsepower and improve turbo spool sound.

Exhaust System

The factory exhaust is restrictive, particularly the downpipe and catalytic converter. A high-flow downpipe (either catless or with a high-flow cat) helps the turbo spool faster and reduces backpressure. A full cat-back exhaust with mandrel-bent tubing and good mufflers rounds out the flow path and adds a pleasant exhaust note.

If you have emissions testing requirements, choose a downpipe with a catalytic converter that still flows well enough to support 350 horsepower. Many aftermarket options exist specifically for the G70.

Reliability and Longevity Considerations

The TD04L-13T is a robust turbocharger, but it still demands reasonable care. Oil quality is critical. Use a high-quality synthetic oil with a viscosity of 5W-30 or 5W-40, depending on your climate. Change the oil every 3,000 to 5,000 miles, especially if you drive the car hard on track days. The turbo sees high temperatures, and degraded oil can lead to coking in the oil passages, which starves the bearings and causes failure.

Let the turbo cool down after hard driving. If you have been pushing the car at high boost for several minutes, idle the engine for 60 seconds before shutting it off. This allows the oil to continue circulating and carry heat away from the center housing. A turbo timer can automate this, but the habit is just as effective.

Inspect the oil feed restrictor periodically. If it becomes clogged, oil flow to the turbo can drop, leading to bearing damage. Some tuners recommend replacing the restrictor with a clean one every 20,000 miles as a precaution.

If you drive the car in winter, be aware that the turbo sees more moisture and cold starts can cause condensation. Ensure the PCV system is functioning properly to prevent oil contamination.

Cost Breakdown and Value Assessment

Budget realistically for this upgrade. A typical TD04L-13T turbocharger costs $400 to $700, depending on whether you buy new or used and whether it includes lines and gaskets. Add $50 to $100 for a gasket set, $50 for oil and coolant lines, and $100 for miscellaneous hardware and fluids.

Tuning costs vary widely. A JB4 unit is around $500. A full standalone ECU with tuning can total $2000 to $3000. Professional dyno tuning adds $500 to $1000 above the hardware costs.

Supporting modifications add up quickly. Expect to spend $300 to $500 on an intercooler, $200 to $400 on a downpipe, $300 to $700 on a cat-back exhaust, and $200 to $400 on an intake.

All told, a complete TD04L-13T upgrade with supporting modifications and professional tuning can range from $2500 to $4500. That is significantly less than building a fully forged engine or swapping to a V8, and it delivers dramatic performance gains. For the cost, the TD04L-13T is one of the best-value upgrades available for the G70.

Frequently Asked Questions

Will the TD04L-13T bolt directly to my stock G70 manifold?
In most cases, yes. The TD04L-13T uses a standard Mitsubishi flange pattern that matches the G70’s exhaust manifold. You may need an adapter plate if the manifold stud spacing differs slightly. Verify the flange pattern before ordering.

Do I need to upgrade the injectors?
On pump gas at boost levels below 20 psi, the stock direct injectors can support the turbo. If you plan to run ethanol or push higher boost, an upgrade is necessary.

How much horsepower can I expect?
With proper tuning, 330 to 380 wheel horsepower is realistic on pump gas. With ethanol and aggressive boost, 400 wheel horsepower is achievable with the right supporting modifications.

Is the TD04L-13T reliable for daily driving?
Yes, as long as you follow proper oil change intervals and let the turbo cool down after hard driving. Many owners use this setup as their daily driver without issues.

What oil pressure should I have at the turbo?
Target 40 to 50 psi at idle. If your engine produces higher oil pressure, install a restrictor in the feed line. Too much oil pressure can blow past the seals and cause smoking.

Conclusion

The Mitsubishi TD04L-13T turbo upgrade is a well-proven path to unlocking the G70 2.0T’s potential. It delivers a substantial increase in horsepower and torque, improves throttle response, and does so without the complexity or cost of larger turbo systems. When paired with proper tuning and the right supporting modifications, it transforms the car into a genuinely fast machine that remains reliable enough for daily use.

If you are considering this upgrade, plan your budget, gather your parts, and take the time to do the installation correctly. Pay attention to oil feed and drain line routing, invest in a proper tune, and monitor your engine’s vitals. The result will be a G70 that pulls hard from low RPM to redline and puts a smile on your face every time you drive it.