Introduction: Why the AMS Performance Turbo Kit for Your Evo X?

Upgrading the turbocharger on your Mitsubishi Lancer Evolution X is one of the most effective ways to unlock serious horsepower and torque. Among the many options available, the AMS Performance Turbo Kit stands out for its proven design, precision engineering, and reliable power delivery. This complete guide will walk you through every step of the installation process, from gathering the right tools to performing the final checks. Whether you are a seasoned DIY mechanic or a dedicated enthusiast, following this guide will help you achieve a safe and successful installation while maximizing the performance gains from your new AMS turbo system.

Before diving in, remember that a turbo upgrade is a major modification. Proper preparation, attention to detail, and a willingness to double-check every connection are essential. If at any point you feel uncertain, consult a professional shop experienced in Evo X builds. This guide assumes you have basic mechanical skills and access to a well-equipped garage.

Tools and Materials Needed

Having everything ready before you start saves time and prevents frustration. Below is a comprehensive list of tools and materials you’ll need for the AMS Performance Turbo Kit installation.

Specialty Tools

  • Torque wrench (3/8″ and 1/2″ drives) – essential for tightening critical fasteners to spec.
  • O2 sensor socket – for removing and installing the wideband oxygen sensor.
  • Turbo stud removal tool (or double-nut method) – helps extract broken or stubborn studs.
  • Flare nut wrench set – for oil and coolant line fittings to avoid rounding.
  • Vacuum pump and gauge – for testing boost reference lines after installation.

Standard Hand Tools

  • Socket set (metric, 6-point preferred) – 8mm through 19mm
  • Combination wrenches (metric)
  • Screwdrivers (flat head and Phillips)
  • Pliers (regular, needle-nose, and snap-ring)
  • Allen keys (metric)
  • Breaker bar (1/2″ drive)
  • Pry bars (small and medium)
  • Hose clamp pliers

Consumables and Parts

  • AMS Performance Turbo Kit (complete with turbo, wastegate, lines, and hardware)
  • New OEM gaskets: turbo to manifold, turbo to downpipe, oil drain, coolant fittings
  • High-temperature thread locker (e.g., Loctite 272)
  • Anti-seize compound for exhaust bolts
  • Coolant (Mitsubishi genuine or equivalent) – plan for topping off after draining
  • Engine oil and filter (for post-install oil change)
  • Oil catch can (recommended to reduce blow-by into intake tract)
  • Zip ties (various sizes) for securing wiring and hoses
  • Shop rags and brake cleaner for cleaning mating surfaces

Safety Gear

  • Safety goggles – protect eyes from debris and fluid splashes.
  • Mechanic’s gloves – cut-resistant preferred when handling sharp edges.
  • Jack and jack stands or lift – work on a level surface; never rely on a jack alone.

Preparation: Setting Up for Success

Proper preparation reduces risk and makes the installation smoother. Start by parking the vehicle on a level concrete floor. Allow the engine to cool completely – a hot exhaust system can cause severe burns and makes bolts more likely to seize as they cool unevenly.

Disconnect the Battery

Remove the negative terminal first, then the positive. This prevents accidental short circuits and resets the ECU, which helps the new tune adapt more cleanly after installation.

Drain Coolant and Oil

Place a drain pan under the radiator petcock and drain the coolant into a suitable container. You will need to disconnect coolant lines to the turbo. Similarly, drain the engine oil to prevent spills when removing the turbo oil drain line. Reinstall the drain plug and fill with fresh oil after the turbo is in place.

Remove Unnecessary Components

Clear access to the turbo area by removing the engine cover, air intake assembly, intercooler piping, and the intercooler itself (if not already off). Label all hoses and connectors with painter’s tape and a marker. Taking photos before disassembly is invaluable for reassembly.

Step-by-Step Installation

Step 1: Remove the Stock Turbo and Manifold

Begin by disconnecting the battery as noted. Remove the upper engine cover and the intake snorkel. Unbolt the heat shields around the turbo and downpipe. Soak the exhaust manifold bolts and turbo-to-downpipe bolts with penetrating oil and allow 10 minutes to penetrate.

Loosen the downpipe bolts, then unbolt the downpipe from the turbo. Disconnect the O2 sensor(s) carefully. If they are stubborn, heat the surrounding area with a propane torch (small flame) to break corrosion, then use the O2 sensor socket. Never force an O2 sensor – the threads are easily damaged.

Remove the oil feed line from the top of the turbo and the coolant lines. Have a catch can ready for any residual coolant. Unbolt the oil drain line from the turbo and the block. Next, remove the turbo-to-manifold bolts (accessed from underneath with a swivel socket). Carefully lift the turbo out of the engine bay. It can be tricky to maneuver; tilt the compressor housing downward while rotating the assembly.

With the turbo out, unbolt the exhaust manifold from the head. Inspect the manifold studs for damage; replace if needed. Clean the mating surfaces on the head and the manifold using a brass brush and brake cleaner.

Step 2: Install the AMS Performance Turbo Kit Manifold and Turbo

Begin by fitting the new manifold (included in the kit) to the cylinder head. Use a new OEM manifold gasket and apply a thin film of anti-seize to the mounting studs. Tighten the manifold nuts to the manufacturer’s torque spec (typically 30-35 ft-lb for the Evo X, but confirm with your kit’s instructions). Work from the center outward in a crisscross pattern to ensure even seating.

Now position the AMS turbocharger onto the manifold. Always use new gaskets – the turbo-to-manifold gasket and the turbo-to-downpipe gasket. Hand-thread the mounting hardware first to avoid cross-threading. The turbo may need to be rotated slightly to align with the oil drain port. Once aligned, torque the nuts to spec (usually 35-40 ft-lb for M10 fasteners, refer to kit documentation).

Reattach the exhaust downpipe using a new gasket. Apply anti-seize to the fasteners. Do not fully tighten yet – leave them snug to allow slight adjustment for final alignment later.

Step 3: Connect the Oil and Coolant Lines

Attach the oil feed line from the block to the turbo center housing. Use a new crush washer on both ends. Tighten the banjo bolts to 25-30 ft-lb – over-tightening can crack the fitting. Next, connect the oil drain line from the turbo to the block. Ensure the drain hose has a smooth, downward slope with no kinks. Many AMS kits include a -10AN drain line; verify the routing clears all hot surfaces.

For the coolant lines, connect the supply and return hoses to the turbo. Some kits use a restrictor in the coolant feed – check that it is installed correctly. Fill the system with coolant after all lines are tight, but leave the radiator cap off for initial burping. Start the engine briefly (see final checks) to circulate coolant, then top off.

Critical: Before starting the engine, verify that all oil and coolant fittings are dry and that clamps are tight. Use a flashlight to inspect rubber hoses for cracks or improper routing near the exhaust manifold.

Step 4: Install the Intake and Intercooler Piping

Mount the new AMS intake system (usually a larger MAF housing or blow-through tube). Ensure the filter is securely clamped and that the intake pipe does not rub against the hood or frame. Install the intercooler piping that came with the kit. Use the supplied silicone couplers and T-bolt clamps. Tighten clamps only enough to compress the coupler without collapsing the pipe – over-tightening can cut the silicone.

If your kit includes a blow-off valve (BOV), mount it according to the instructions. For recirculating setups, ensure the recirculation tube is properly connected and zipped-tied away from moving parts.

Reinstall the intercooler (if removed) and tighten all charge pipe connections. Check for clearance between the pipes and the radiator fan shroud, power steering lines, and A/C lines. Use zip ties to secure any loose wiring or stray hoses.

Step 5: Reconnect Sensors and Electrical Components

Reconnect the O2 sensor(s) to the downpipe. Use anti-seize on the threads (not on the sensor tip) to prevent future seizing. Plug in the MAP sensor and any boost control solenoid connectors that may have been detached. Reattach the battery (positive first, then negative) and carefully route the battery cables away from hot areas.

Now is a good time to install or check your oil catch can. Mount it in a location where it can be easily drained. Connect the crankcase vent lines (from the valve cover and intake manifold) to the catch can, following the plumb-in instructions. This reduces oil vapors entering the intake tract, keeping the turbo and intercooler cleaner.

Final Checks and First Start

Before starting the engine, perform a thorough inspection. Walk around the engine bay and verify every bolt, clamp, and connection. Pay special attention to:

  • Oil feed and drain lines – no leaks, no kinks.
  • Coolant hoses – secure at both ends.
  • Intake and intercooler pipes – all clamps tight, no gaps.
  • Wastegate actuator rod – properly connected and free to move.
  • All fasteners – especially manifold and turbo mounting nuts.

Fill the engine with fresh oil (use a high-quality synthetic 5W-40 or as specified by your tuner). Fill coolant to the full line but leave the reservoir cap loose to allow air to escape.

First Startup Procedure

Crank the engine for 15-20 seconds without starting (disable fuel pump or ignition fuse) to build oil pressure. Re-enable and start the engine. Let it idle for 2-3 minutes. Watch for oil pressure on the gauge – it should reach normal range within a few seconds. Listen for any unusual noises like grinding, whistling (other than normal spool), or knocking. If something sounds wrong, shut off immediately and investigate.

While idling, check all oil and coolant connections for leaks. Use a clean rag to wipe suspicious areas and watch for wetness. Also check the exhaust system for exhaust leaks; a puffing sound at the turbo flange indicates a bad gasket.

After the engine reaches operating temperature (coolant fan cycles on and off), turn off the engine and let it cool. Recheck coolant level and top off as needed. Re-torque the downpipe bolts and any exhaust flanges after a heat cycle, as they tend to settle.

Tuning and ECU Calibration

Installing an AMS Performance Turbo Kit requires professional tuning. The increased airflow and boost capacity will overwhelm the stock ECU calibration. Do NOT drive the car hard or boost beyond wastegate spring pressure without a proper tune. Contact a reputable Evo X tuner who uses ECUFlash, Cobb Accessport, or EcuTek to recalibrate fuel, timing, and boost control maps. Many AMS kits include a base flash file, but a custom dyno tune is strongly recommended for safety and performance.

While waiting for tuning, you can idle the car and do very short low-rpm trips (under 3,000 rpm) to break in the turbo and confirm no leaks. However, any boost event above wastegate pressure without tuning can cause detonation and engine damage.

Post-Installation Maintenance and Tips

  • First oil change: Change oil and filter after the first 500 miles to remove any debris from the new turbo and assembly.
  • Check boost leaks: Use a boost leak tester (available at any auto parts store) to pressurize the intake system to 15 psi. Listen for hissing and fix any leaks immediately.
  • Monitor oil and coolant levels for the first few weeks.
  • Inspect the wastegate and BOV operation periodically – ensure no sticking.
  • If you installed an oil catch can, drain it every oil change.

Common Mistakes to Avoid

  • Using old gaskets or crush washers – always use new; they are cheap insurance against leaks.
  • Over-tightening banjo fittings – strip threads or crack the turbo housing; use a torque wrench.
  • Routing oil drain line uphill – causes oil backup and turbo seal failure; maintain a continuous downward slope.
  • Running without a tune – even a few seconds of boost can cause knock and catastrophic engine failure.
  • Neglecting to bleed coolant system – air pockets cause engine overheating.

Conclusion: Enjoy the Rewards of Your AMS Turbo Upgrade

Installing the AMS Performance Turbo Kit on your Evo X is a rewarding project that transforms the car’s driving experience. With careful attention to each step – from removing the stock turbo to final tuning – you can achieve a reliable, high-horsepower build that holds up on the street and track. This guide provides the foundational steps, but always reference the specific instructions that come with your kit and reach out to AMS’s technical support if you have questions. Once properly installed and tuned, your Evo X will deliver the thrilling acceleration and responsiveness that the 4B11T engine is famous for.

For further reading and technical resources, check out the AMS Performance official website for product updates, and the EvolutionM Evo X engine forum for community advice. If you need professional tuning, consider reaching out to a certified Cobb Tuning pro tuner or a local dyno shop experienced with Mitsubishi ECUs.