Installing the Wagner Tuning S3 IS38 Turbo Kit is one of the most impactful upgrades you can perform on your 2.0T EA888 Gen 3 engine. This kit replaces the stock turbocharger with a larger, more efficient unit that is capable of significantly increasing horsepower and torque output. Designed for vehicles such as the Audi S3, Volkswagen Golf R, and related models, the IS38 turbocharger is a proven upgrade that can push your car into the 400+ wheel horsepower range when paired with supporting modifications and proper engine calibration. This comprehensive guide provides step-by-step instructions to help you through the installation process safely and effectively. Before starting, ensure you have all necessary tools, parts, and a clear understanding of the work involved. If you are not experienced with turbocharger replacement, consider consulting a professional technician.

Tools and Materials Needed

Having the correct tools and materials on hand is critical for a smooth installation. Below is a detailed list of what you will need:

  • Wagner Tuning S3 IS38 Turbo Kit – includes the turbocharger, gaskets, bolts, and often updated lines or adapters.
  • Socket set – metric 8mm, 10mm, 13mm, 15mm, 18mm, and 21mm sockets, including deep and shallow versions.
  • Torque wrench – essential for tightening critical fasteners to manufacturer specifications. A 3/8‑inch drive for lower torque ranges and a 1/2‑inch drive for higher values are recommended.
  • Screwdrivers – flathead and Phillips for hose clamps and electrical connectors.
  • Wrenches – combination wrenches in 10mm, 13mm, 15mm, 18mm, and 21mm, plus a line wrench for oil and coolant fittings.
  • Pliers – slip‑joint pliers and hose clamp pliers for coolant and vacuum lines.
  • Vacuum hose removal tool – to safely disconnect vacuum lines without damaging the connectors.
  • E‑torx sockets – required for some factory turbo and manifold bolts (E8, E10, E12 sizes).
  • Hex (Allen) keys – for some aftermarket components or heat shield fasteners.
  • Oil catch pan – to collect any fluids that may drain during disconnection of oil lines.
  • Engine oil – 5W‑40 or 0W‑40 meeting VW 502.00/504.00 specification. You will need about 5.5‑6 quarts after the oil change.
  • Coolant – G12+, G13, or compatible long‑life coolant. You may need to top up after coolant line disconnection.
  • New gaskets – the Wagner kit typically includes the necessary manifold gasket, turbo outlet gasket, and oil return line gasket. However, it is wise to have additional exhaust manifold stud nuts and copper crush washers for the oil feed line on hand.
  • Shop towels – for cleaning and wiping spilled fluids.
  • Safety glasses and gloves – to protect yourself from debris and chemicals.
  • Jack and jack stands – to raise the vehicle for underside access. Ramps can also work but stands are safer.
  • Flashlight or inspection light – many areas are in shadowed parts of the engine bay.
  • PB Blaster or penetrating oil – to loosen rusted nuts and bolts.

Preparation Steps

Proper preparation minimizes the risk of mistakes and ensures you have a clean, organized workspace. Follow these steps before beginning any mechanical work:

  • Park on a level surface and engage the parking brake. Place wheel chocks behind the rear wheels for safety.
  • Disconnect the battery – remove the negative terminal first, then the positive. Wait at least 5 minutes for the electronic systems to discharge. This prevents accidental short circuits and protects the ECU.
  • Allow the engine to cool completely. A cold engine is safer to work on, especially when handling coolant and oil lines.
  • Drain the engine oil (if you plan to change it) and remove the oil filter. This step is recommended because the turbo oil feed line will be disconnected and you can start fresh with clean oil. If you do not drain the oil, have a catch can ready for oil that will drain from the oil feed line.
  • Drain the coolant by opening the radiator drain valve or disconnecting the lower radiator hose. You do not need to fully drain the entire system, but enough to prevent spillage when disconnecting turbo coolant lines. Collect coolant in a clean container for reuse if it is still fresh.
  • Remove the engine cover – unscrew the bolts or release the push‑clips that hold the cover in place. Set it aside.
  • Clear the workspace – have all tools and parts laid out within easy reach. Use a magnetic tray for small bolts and nuts to avoid losing them.
  • Inspect the Wagner Tuning kit – verify all components are present and undamaged. Check the turbocharger for smooth rotation of the compressor and turbine wheels – any friction indicates damage and should be addressed before installation.

Removing the Stock Turbocharger

Removing the factory IS20 or IS38 turbocharger requires careful disassembly of several components. Take your time and label any hoses or connectors you disconnect. The following steps reflect a typical removal process on a transverse 2.0T EA888 engine.

Step 1: Remove the Air Intake System

  • Loosen the hose clamp at the turbo inlet and disconnect the intake pipe from the turbocharger.
  • Disconnect the mass airflow (MAF) sensor electrical connector.
  • Remove the entire air intake assembly from the air box to the turbo to gain clearance.

Step 2: Disconnect Vacuum Lines and Electrical Connectors

  • Unplug the vacuum line from the diverter valve (if equipped with an electronic diverter valve, unplug the connector).
  • Disconnect the electrical connector from the wastegate actuator. Some models have a two‑wire connector on the side of the turbo.
  • Remove the vacuum hose that goes to the turbo actuator canister.
  • If your vehicle has a N75 solenoid, disconnect the hoses attached to it (note or photograph their routing).

Step 3: Remove the Catalytic Converter / Downpipe

  • Raise the vehicle and support it securely on jack stands.
  • Unbolt the downpipe from the turbo outlet. This usually involves three or four nuts (use penetrating oil if needed).
  • Disconnect the oxygen sensor electrical connectors and unthread the sensors from the downpipe.
  • Remove the downpipe completely. You may need to remove the heat shield covering the steering rack to free the downpipe.
  • Be careful not to damage the oxygen sensors – use an oxygen sensor socket to avoid rounding the hex.

Step 4: Remove the Turbocharger Oil and Coolant Lines

  • Locate the oil feed line on top of the turbo – use a line wrench to loosen it at the turbo banjo bolt. Have a drip pan ready; some oil will spill.
  • Disconnect the oil return line from the bottom of the turbo. This is often a flanged fitting with two bolts. Collect any oil that drains.
  • Remove the coolant supply and return lines from the turbo. Use a line wrench and be ready for some coolant to drip.
  • Plug the open ends of the lines and the turbo ports to keep debris out.

Step 5: Unbolt the Turbo from the Exhaust Manifold

  • The turbo is bolted to the exhaust manifold via three or four nuts. Use a long extension and a swivel socket to reach the lower nuts.
  • Once all nuts are removed, carefully lift the turbocharger away from the manifold. It may be stuck due to a gasket; gently pry it loose.
  • Remove the turbo from the engine bay. This may require rotating it and wiggling it past the manifold and engine mount.
  • Inspect the manifold studs – if any are damaged, replace them before installing the new turbo.

Step 6: Clean the Mounting Surfaces

  • Scrape away any leftover gasket material from the exhaust manifold and the turbo oil return flange.
  • Wipe the area clean with shop towels. Avoid using compressed air near the open oil drain hole – debris can fall into the engine.

Installing the Wagner Tuning S3 IS38 Turbo Kit

With the stock turbo removed and the mounting surfaces cleaned, you are ready to install the Wagner Tuning S3 IS38 Turbo Kit. Follow these steps closely, paying attention to torque specifications and gasket placement.

Step 1: Prepare the New Turbocharger

  • Remove the Wagner Tuning turbo from its packaging. Rotate the compressor wheel by hand to ensure it spins freely.
  • Transfer any brackets or components from the old turbo, such as the heat shield bracket or EGT sensor, if not included in the kit.
  • Install the new gaskets on the turbo’s inlet and outlet flanges. Some kits provide a manifold gasket – place it on the exhaust manifold.
  • If the kit includes an upgraded wastegate actuator or requires actuator adjustment, set the preload according to the instructions supplied with the kit. Typical preload is 3‑5mm of rod length reduction.

Step 2: Mount the Turbo to the Exhaust Manifold

  • Position the new turbo against the exhaust manifold. Make sure the turbo oil drain sits correctly over the oil return hole in the engine block.
  • Thread the manifold nuts (or studs) and torque them to the manufacturer’s specification, usually around 22‑25 Nm (16‑18 lb‑ft) for M8 fasteners. Use a cross‑pattern to evenly seat the turbo.
  • Reconnect the vacuum lines and electrical connectors to the wastegate actuator and the diversion valve. Ensure the vacuum hoses are routed away from hot surfaces.

Step 3: Connect the Oil and Coolant Lines

  • Oil feed line: Use a new copper crush washer on the banjo bolt. Torque the banjo bolt to 20 Nm (15 lb‑ft). Do not overtighten – the aluminum turbo housing can crack.
  • Oil return line: Install a new gasket and secure the return flange with two bolts. Torque to 10 Nm (7 lb‑ft). Ensure the line is not kinked or stressed.
  • Coolant lines: Connect both the supply and return lines using new gaskets or O‑rings if provided. Torque banjo bolts to 15 Nm (11 lb‑ft). Tighten any hose clamps securely.
  • Check all connections for alignment – nothing should be pulling at an angle.

Step 4: Reinstall the Downpipe

  • Install the downpipe onto the turbo outlet with a new gasket. Use the provided bolts or nuts and torque to 25‑30 Nm (18‑22 lb‑ft).
  • Reconnect the oxygen sensors and route the wiring to avoid the manifold and turbo.
  • Install any removed heat shields.

Step 5: Reassemble the Intake System

  • Reattach the intake pipe to the turbo inlet. Tighten the hose clamp.
  • Reconnect the MAF sensor and plug in any other sensors that were disconnected.
  • Install the engine cover.

Connecting the Necessary Components – Final Checks

Before completing the installation, double‑check every connection. This step prevents post‑installation issues such as oil leaks, boost leaks, or electrical faults.

  • Verify all electrical connectors are fully seated – especially the wastegate actuator, MAF, and oxygen sensors.
  • Ensure all vacuum lines are correctly routed and not cracked or blocked. A boost leak can cause poor performance.
  • Check that no tools or loose parts are left in the engine bay.
  • Install the battery, reconnecting the positive terminal first, then the negative. Tighten terminals securely.
  • Fill the engine with fresh oil if you drained it earlier. Pour slowly to avoid aeration, and check the level with the dipstick.
  • Top off the coolant system. You may need to bleed air by running the engine with the coolant reservoir cap off and heater on maximum.
  • Start the engine and let it idle for a few minutes. Do not rev it. Watch for oil pressure – the warning light should turn off within seconds.
  • Inspect for leaks around the turbo, oil lines, coolant lines, and downpipe junction. Tighten any connections that show dampness.
  • After the engine reaches operating temperature, perform a visual inspection under the car and check the oil level again. Top off as needed.
  • Take a short test drive to verify boost builds smoothly and no unusual noises are present. Listen for turbo spool, wastegate chatter, or exhaust leaks.

Performance Benefits and Tuning Requirements

The Wagner Tuning S3 IS38 Turbo Kit is designed to deliver significant power gains over the factory IS20 turbo. With the kit properly installed and an appropriate engine tune, you can expect peak gains of 70‑100 wheel horsepower and substantial mid‑range torque increases. The larger turbine and compressor wheels allow the engine to breathe more freely at higher boost levels, supporting power up to around 430‑450 wheel horsepower with auxiliary fueling and intercooling.

However, the IS38 turbocharger requires a custom engine calibration to work correctly. The factory ECU will not supply the correct fuel and ignition maps for the increased airflow, which can lead to detonation, high exhaust gas temperatures, and potential engine damage. It is essential to install a properly tuned ECU flash from a reputable tuner such as Unitronic, APR, or COBB Tuning. Many tuners offer off‑the‑shelf IS38 tunes that pair well with the Wagner kit, but a custom dyno tune can further optimize performance for your specific fuel and supporting modifications.

Supporting modifications to consider include a larger intercooler (to reduce intake air temperatures), a high‑flow intake, a turbo‑back exhaust system, and upgraded fuel injectors and high‑pressure fuel pump if aiming for the upper end of the power band.

Conclusion

Installing the Wagner Tuning S3 IS38 Turbo Kit is a rewarding project that can transform your driving experience. The step‑by‑step instructions provided in this guide cover all critical aspects: preparation, removal of the stock turbo, installation of the new unit, and post‑installation checks. By following these steps with care and attention to detail, you can ensure a successful upgrade that delivers reliable, increased performance. Always consult the manufacturer’s documentation for the specific parts included in your kit, and do not hesitate to seek professional help if any step seems beyond your comfort level. After installation, treat your car to a proper tune and enjoy the new power.

For further information on the Wagner Tuning S3 IS38 Turbo Kit, visit the Wagner Tuning official website. Additional community resources and installation tips can be found on forums like GolfMK7 and Audizine.