The Mitsubishi Evo IX TD05H-16G8 Turbo Upgrade: Your Complete Guide to Reaching 370 Horsepower

The Mitsubishi Lancer Evolution IX is one of the most celebrated performance sedans of its era, thanks in large part to its robust 4G63 engine and the tuning potential that lies within. For owners looking to move beyond the factory turbocharger and unlock a serious power increase, the TD05H-16G8 turbocharger is a proven and popular choice. This upgrade is widely recognized for its ability to push the Evo IX to a reliable and highly enjoyable 370 horsepower threshold when paired with the right supporting modifications. This guide provides a detailed, shop-quality walkthrough of the installation process, covering everything from essential tools and preparation to final tuning considerations. Whether you are an experienced DIY mechanic or a shop technician, following this process carefully will help you achieve a clean installation and maximum performance from your new turbo setup.

Understanding the TD05H-16G8 Turbocharger and the 370 HP Goal

Before diving into the installation, it is important to understand exactly what the TD05H-16G8 offers and why it is such an effective upgrade for the Evo IX. The stock turbocharger on the Evo IX is capable, but it runs out of breath in the upper RPM range and limits top-end power. The TD05H-16G8 is a direct upgrade within the Mitsubishi turbo family, offering a larger compressor wheel and a revised turbine housing that flows significantly more air without introducing excessive lag.

  • Compressor Side: The 16G8 compressor wheel moves substantially more air than the stock unit, supporting the airflow requirements for 370 horsepower at moderate boost levels. This allows the engine to make strong power without extreme intake temperatures or backpressure.
  • Turbine Side: The TD05H turbine housing retains excellent spool characteristics, meaning boost comes on quickly and predictably. This makes the car very streetable while still delivering the top-end punch needed for track days or spirited driving.
  • Reliability Factor: The TD05H series is known for its robust construction and durability. It handles sustained high RPM operation and elevated boost pressures well, provided the oil supply and cooling systems are properly maintained.

The 370 horsepower target is a sweet spot for this turbocharger. It is well within the compressor map's efficient range, meaning you are not pushing the turbo to its limits for daily driving. This power level also aligns well with the capabilities of the stock fuel system after reasonable upgrades (injectors and fuel pump) and a quality ECU tune. Reaching 370 wheel horsepower typically requires boost levels in the 22-24 PSI range on pump fuel, which the TD05H-16G8 handles with authority.

Essential Tools and Materials for the Installation

Having the right tools and replacement parts on hand before you begin will save significant time and prevent frustrating delays. Categorize your preparation into hand tools and consumable items.

Hand Tools and Specialty Items

  • Socket set: 1/4-inch and 3/8-inch drive sets with metric sockets ranging from 8mm to 19mm.
  • Wrench set: Combination wrenches in metric sizes, especially 10mm, 12mm, 14mm, and 17mm.
  • Torque wrench: A 3/8-inch drive torque wrench capable of 10-80 ft-lb for critical fasteners such as manifold bolts and turbo mounting nuts.
  • Screwdrivers: Phillips and flathead screwdrivers for hose clamps and electrical connectors.
  • Swivel sockets and extensions: Essential for reaching bolts in tight spots, particularly on the lower manifold and turbine housing.
  • Oil catch pan and shop towels: To manage spills from oil and coolant lines.
  • Jack and jack stands: To safely raise the vehicle for better access to under-car components.
  • Penetrating oil: Apply to exhaust manifold bolts and O2 sensor threads the night before to ease removal.

Replacement Parts and Consumables

  • Replacement gaskets: Exhaust manifold to cylinder head gasket, turbo to manifold gasket, downpipe to turbo gasket, and oil return line gasket.
  • New oil feed and return line crush washers: These are single-use and must be replaced to prevent leaks.
  • High-temperature anti-seize compound: Apply to exhaust bolts to prevent future seizure.
  • Fresh engine oil and filter: You will be draining the oil, so a full oil change is part of the process.
  • Coolant: Mitsubishi-specified or equivalent HOAT coolant for refilling after draining.
  • Thread locker (medium strength): For any fasteners that are prone to vibration loosening.

Step 1: Preparation and Safety

Proper preparation reduces the risk of mistakes and accidents. Start by disconnecting the battery negative terminal to eliminate any chance of short circuits or accidental engine cranking during disassembly. Next, place the vehicle on jack stands if you need access from below. Drain the engine oil and coolant completely. Draining these fluids before disconnecting lines minimizes mess and prevents contamination of the new turbocharger. Remove the intercooler piping, intake pipe, and any heat shields that block access to the turbocharger. It is also advisable to remove the radiator fan shroud for additional working room on the front of the engine.

Step 2: Removing the Stock Turbocharger

With the engine bay prepared, you can begin removing the factory turbocharger. Work methodically and label any connectors or hoses that you disconnect.

  • Exhaust Manifold Bolts: Loosen and remove the exhaust manifold bolts. These are often tight and can be seized. Apply penetrating oil and use steady pressure. Consider heating the manifold flange area with a torch if bolts are stubborn, but take care not to damage surrounding components.
  • Oil Feed and Return Lines: Disconnect the oil feed line from the top of the turbo and the oil return line from the bottom. Have a catch pan ready for residual oil. Replace the crush washers during reassembly.
  • Coolant Lines: The stock turbo uses water-cooling. Disconnect the coolant supply and return lines. Be prepared for some coolant to drain out.
  • Downpipe and O2 Sensor: Remove the bolts connecting the downpipe to the turbo outlet. If the O2 sensor is in the downpipe, carefully unscrew it to avoid damaging the threads.
  • Turbo Mounting Bracket: Remove the bracket that supports the turbocharger from the block. This bracket hangs the turbo in position and must be removed to free the unit.
  • Removal: Gently wiggle the old turbocharger free from the manifold and lift it out. Inspect the manifold mounting surface for any gasket material residue and clean it thoroughly.

Step 3: Pre-Installation Checks for the New TD05H-16G8

Before bolting on the new turbo, perform some critical checks. Inspect the TD05H-16G8 unit for any signs of shipping damage or debris in the compressor housing. Spin the compressor wheel by hand to verify it rotates freely without binding or scraping. It is also highly recommended to pre-oil the turbocharger. Pour a small amount of clean engine oil into the oil feed port and spin the turbine shaft by hand. This ensures the bearings are lubricated immediately upon engine start, preventing dry start damage. Apply a thin coat of anti-seize to the exhaust manifold studs and the downpipe studs. Install new gaskets on the manifold flange and turbo outlet.

Step 4: Installing the TD05H-16G8 Turbocharger

Now the new turbo goes in. This process is essentially the reverse of removal, but attention to detail is critical.

  • Mounting the Turbo: Carefully position the TD05H-16G8 onto the exhaust manifold studs. Use a new gasket. Install the turbo mounting bracket loosely to support the unit, then torque the turbo-to-manifold nuts to 35-40 ft-lb in a crisscross pattern. Torque the bracket bolts to 45 ft-lb.
  • Oil Line Connections: Connect the oil feed line using new crush washers. Torque the banjo bolt to 25-30 ft-lb. Connect the oil return line with a fresh gasket and tighten securely, but avoid over-torquing the aluminum fittings.
  • Coolant Line Connections: Reconnect the coolant supply and return lines. Use new clamps and verify there are no kinks in the hoses. Torque banjo fittings to specification.
  • Downpipe Installation: Attach the downpipe to the turbo outlet with a new gasket. Torque the downpipe nuts to 30-35 ft-lb. Reinstall the O2 sensor if removed.
  • Wastegate and Actuator: If your turbo kit includes an upgraded wastegate actuator, adjust it according to the manufacturer's settings. Ensure the wastegate arm moves freely and the actuator rod is properly aligned. For a 370 HP target, a boost controller or actuator set to around 22-24 PSI is appropriate.

Step 5: Reconnecting Components and Final Assembly

With the turbo secured, reconnect the intake piping and intercooler hoses. Ensure all couplers are clean and clamps are tightened evenly. Reinstall the heat shields, fan shroud, and any other components removed for access. Refill the engine oil and coolant to the correct levels. Double-check that all electrical connectors are firmly plugged in and all bolts are torqued to specification. This is the time to catch any loose connections or forgotten steps.

Step 6: Initial Start-Up and Break-In Procedure

Start the engine and let it idle. Do not rev the engine immediately. Allow it to run at idle for 10-15 minutes to circulate oil and coolant through the new turbocharger. Listen for any unusual noises such as scraping, whining, or exhaust leaks. Inspect the oil feed and return lines, coolant hoses, and all gasket surfaces for leaks. If everything looks and sounds correct, raise the RPM to about 2000-2500 for a few minutes to seat the turbo seals under light load. Shut the engine off and let it cool completely. Repeat this heat cycle process once more before driving the car under load. This break-in procedure helps the turbo seals and bearings settle into place.

Step 7: Tuning for 370 Horsepower

Installing the TD05H-16G8 turbocharger alone will not net you 370 horsepower. The turbo upgrade must be accompanied by proper engine management tuning. You will need to have your ECU retuned via a reliable platform such as ECUFlash or a standalone ECU. The tuner will calibrate fuel maps and ignition timing to match the increased airflow of the 16G8 turbo. A wideband oxygen sensor is essential during the tuning process to monitor air-fuel ratios. Target an AFR of approximately 11.5:1 under boost for safety. Do not drive the car aggressively until the tune is finalized by a professional. Pushing the engine without proper calibration risks severe damage.

Step 8: Supporting Modifications for the 370 HP Target

To safely achieve and sustain 370 horsepower with the TD05H-16G8, certain supporting modifications are strongly recommended. These components ensure the engine can deliver the fuel and airflow the turbo requires.

  • Fuel System: Upgrade to 750cc-1000cc fuel injectors and a 255 LPH fuel pump. The stock fuel system will hit its limits well below 370 HP.
  • Intercooler: A larger front-mount intercooler is necessary to keep intake air temperatures in check on hot days and during sustained pulls.
  • Intake and Exhaust: A 3-inch turbo-back exhaust with a high-flow catalytic converter or test pipe will reduce backpressure. A cold air intake helps the turbo breathe more freely.
  • Boost Controller: A manual or electronic boost controller provides precise adjustment of boost levels to hit the 22-24 PSI target.

Long-Term Maintenance and Reliability Tips

After installation, maintaining the turbocharger is key to its longevity. Use high-quality synthetic oil and change it every 3,000-4,000 miles. Always allow the engine to idle for about 30-60 seconds before shutdown to cool the turbo and prevent oil coking. Check for boost leaks regularly by performing a pressure test on the intake system. Inspect the oil return line for blockages or kinks that could cause seal failure. With proper care, your TD05H-16G8 will deliver years of reliable 370+ horsepower driving.

Conclusion

Installing the TD05H-16G8 turbocharger on your Mitsubishi Evo IX is one of the most rewarding upgrades you can perform. It transforms the car's power delivery, providing strong mid-range torque and impressive top-end pull while maintaining a very streetable nature. By following this comprehensive guide and paying attention to preparation, installation details, and tuning, you can achieve a solid and reliable 370 horsepower setup. Take your time, use quality parts, and invest in a professional tune. Your Evo IX will reward you with an exhilarating driving experience that few other sedans can match.

For further research on turbocharger specifications and tuning strategies, consult resources such as MAPerformance for available upgrade kits and support parts, or visit technical forums like EvolutionM.net for community insights. Understanding the compressor map and matching your goals to the hardware is essential for success, and Garrett Motion offers excellent educational content on turbocharger fundamentals that apply to all brands.