Table of Contents

Overview of the Garrett GTX2867R Upgrade for Your Audi TT

Upgrading your Audi TT with a Garrett GTX2867R turbocharger is one of the most effective ways to unlock serious horsepower and torque gains. The GTX2867R is a direct-fit, ball-bearing turbo known for its quick spool, high flow capacity, and excellent thermal efficiency. For 1.8T and 2.0T FSI engines found in the Mk1, Mk2, and Mk3 TT chassis, this swap can push power past the 350–400 whp range with supporting modifications.

This guide provides a complete, step-by-step installation procedure. It covers everything from tool preparation and removal of the factory turbo to final leak testing and initial tuning considerations. Follow each step carefully to ensure a reliable, high-performance build.

Required Tools, Parts, and Materials

Before beginning, gather all necessary components and tools. Missing a part mid-install can lead to unnecessary downtime.

Core Components

  • Garrett GTX2867R turbocharger (part number 857154-5001S or equivalent direct-fit variant)
  • Turbo installation gasket kit (manifold to turbo, turbo to downpipe, oil return line gaskets)
  • High-temperature silicone couplers and T-bolt clamps (for intake and intercooler piping)
  • Oil feed line (stainless steel braided line with proper restrictor if required)
  • Oil drain line and flange (must match GTX2867R CHRA)
  • Coolant feed and return lines (use original Audi lines if compatible, otherwise upgrade)
  • Boost tap or boost gauge sender
  • Heat wrap or thermal barrier (optional but recommended for intake piping)

Tools

  • Metric socket set (8–19 mm, 3/8” and 1/2” drive)
  • Deep sockets for exhaust manifold nuts
  • Wrenches (combination and crowfoot for oil lines)
  • Torque wrench (ft-lb and in-lb ranges)
  • Pry bar or flathead screwdriver (for stubborn O2 sensors or old gaskets)
  • Jack and jack stands (or lift)
  • Penetrating oil (like PB Blaster) for rusted fasteners
  • Safety glasses, mechanic gloves, and floor drains or catch pans

Consumables

  • Fresh engine oil and filter (recommend full synthetic 5W-40 or 0W-40)
  • Coolant (G12+ or equivalent)
  • Thread-locker (medium strength)
  • Anti-seize compound for exhaust nuts

Pre-Installation Preparation

Proper preparation reduces risk of damage to the engine, new turbo, and yourself. Work in a clean, well-ventilated garage or shop.

1. Disconnect the Battery

Disconnect the negative battery terminal. This prevents accidental shorts, electrical spikes, and damage to the ECU when working near sensors and wiring.

2. Drain Coolant and Engine Oil

Remove the oil drain plug and drain the oil into a suitable container. Drain the radiator coolant by opening the petcock or removing the lower radiator hose. This step is necessary because you will be removing both the oil drain line from the sump and the coolant lines from the turbo. Reusing old oil is not advised; replace with fresh oil and filter after turbo installation.

3. Remove the Engine Under Tray and Air Intake Assembly

Take off the engine under tray (if equipped). Then remove the factory air box, air filter, and all intake ducts leading to the turbo inlet. Also disconnect the mass airflow (MAF) sensor and set it aside carefully.

4. Remove the Intercooler Piping

Disconnect the charge air pipes from the turbo outlet to the intercooler. On most TT models, this involves removing silicone couplers and clamps on the hot and cold sides. Label the pipes if you plan to reuse them.

5. Remove the Exhaust Components

If your TT has a factory downpipe, loosen the bolts connecting the downpipe to the turbo and the mid-pipe. You may need to disconnect the O2 sensor(s) to fully free the downpipe. Support the exhaust with a jack or hanger to prevent strain on the rear section.

Removing the Factory Turbocharger

Now remove the original turbo. Work slowly to avoid damaging coolant or oil lines that can be reused.

1. Unbolt the Exhaust Manifold

The turbo is mounted directly to the exhaust manifold. Using penetrating oil on the manifold-to-head nuts, loosen them with a deep socket and ratchet. Remove all nuts and carefully pull the manifold and turbo assembly away from the cylinder head. Watch out for the turbo outlet flange that connects to the downpipe.

2. Disconnect Oil Feed and Return Lines

The oil feed line usually enters the top or side of the turbo center section. The oil return line connects to a fitting on the oil pan. Use a wrench to loosen, not force, the fittings. The return line often has a crush washer – replace it during reassembly.

3. Disconnect Coolant Lines

Loosen the banjo bolts retaining the coolant supply and return lines. Some coolant may spill; have a rag ready. Inspect the O-rings inside the fittings; replace if worn or hard.

4. Remove the Manifold and Turbo Assembly

Lift the manifold and turbo combination away from the engine. On some TTs, you may need to remove a heat shield or brackets to clear the valve cover. Place the assembly on a bench for disassembly. Do not reuse the factory turbo – it is likely worn or at high mileage.

Preparing the Garrett GTX2867R for Installation

The new turbo requires a few preparatory steps before it can be bolted on.

1. Inspect the Turbo

Remove the GTX2867R from its packaging. Rotate the compressor and turbine wheels by hand – they should spin freely with no binding. Check the inlet and outlet ports for debris or shipping damage.

2. Install Oil and Coolant Fittings

Install your pre-purchased oil feed fitting (usually a -4AN or M10x1.0) into the oil inlet port. Use thread-locker or Teflon tape for pipe threads, but avoid getting any material inside the turbo. Attach the oil drain flange with a new gasket. For coolant, install the banjo fittings or AN adapters as per the kit instructions.

3. Clock the Turbo Center Section

Garrett ball-bearing turbos allow you to rotate the center housing rotating assembly (CHRA) to align oil and coolant lines with your engine layout. Loosen the clamp bands (actuator housing or backing plate) slightly, rotate the CHRA to the desired position, then retighten to the specified torque. Do not overtighten – refer to Garrett’s torque values (typically 4–5 Nm for the c-clip screw).

4. Install the Wastegate Actuator (if separate)

The GTX2867R often ships with an internal wastegate actuator. If your kit includes it, mount the actuator bracket to the turbine housing and attach the actuator rod to the wastegate arm. Adjust rod length to achieve the desired base boost (usually 10–14 psi for street applications).

Installing the New Turbo and Manifold

With the new turbo prepared, you can now mount it to the manifold or directly to the engine.

1. Attach the Turbo to the Exhaust Manifold

If you have a separate aftermarket manifold, bolt the turbo to the manifold using new hardware. Use a new manifold-to-turbo gasket. Apply a small amount of anti-seize on the studs or bolts. Torque to manufacturer specifications (usually 30–40 ft-lb for M10 hardware).

2. Install the Manifold and Turbo Assembly

Carefully lift the assembly back into the engine bay. Align the manifold studs with the cylinder head holes. You may need to rotate the turbo slightly to clearance the engine mount or coolant pipes. Install the manifold nuts new OEM or Grade 8. Torque in a crisscross pattern per head specs (typically 18–22 ft-lb for M8 nuts). Recheck after a few heat cycles.

3. Connect the Downpipe

Attach the downpipe to the turbine outlet. Use a new gasket. If your downpipe is aftermarket with a v-band clamp, simply close the clamp and tighten to 5–7 ft-lb. For flanged connections, use new studs and nuts tightened to 30–35 ft-lb.

Connecting Oil, Coolant, and Boost Lines

Proper line routing is critical for turbo reliability. Use only high-temperature rated hoses and fittings.

1. Oil Feed Line

Connect one end to the turbo oil inlet. Connect the other end to the engine oil supply – usually at the oil filter housing or a sandwich plate. If using a sandwich plate, ensure it has a restrictor if the turbo requires one (Garrett specifies 0.060” restrictor for journal bearings; ball bearing uses a larger feed). Run the line away from heat sources. Torque fittings to 12–15 ft-lb.

2. Oil Return Line

The oil drain line must slope downhill from the turbo to the pan without any kinks or low spots. Attach the drain flange to the turbo and the other end to a bung on the oil pan (or the factory return location). Use a new crush gasket. Tighten bolts to 7–10 ft-lb.

3. Coolant Lines

Connect the coolant supply and return hoses. The coolant flows from the engine block into the turbo and returns to the coolant reservoir or coolant pipe. If your kit uses silicone hoses, secure them with constant-tension clamps. Bleed the cooling system later.

4. Boost Control Reference

If running a manual boost controller or electronic boost controller, connect a vacuum line from the turbo compressor outlet or intercooler piping to the controller. Also connect the wastegate actuator. Ensure all lines are secure and not kinked.

Reassembling Intake and Exhaust Systems

With the turbo mechanically installed, reconnect the intake, intercooler, and exhaust.

1. Install the Intake System

Mount the aftermarket intake pipe onto the turbo compressor inlet. Use a quality silicone coupler and T-bolt clamp. Reinstall the MAF sensor in the correct orientation. On blow-through MAF setups, the sensor must be placed after the intercooler. Follow your kit instructions.

2. Reconnect Intercooler Piping

Attach the hot side charge pipe from the turbo outlet to the intercooler, and the cold side from the intercooler to the throttle body. Use new silicone couplers if the originals are worn. Tighten clamps securely but do not overtighten (damages couplers).

3. Reinstall the Downpipe and Exhaust

Connect the downpipe to the mid-pipe and muffler section. Use new gaskets and fasteners. Reconnect any O2 sensors. If the downpipe is not catted, you may need a O2 sensor spacer to prevent Check Engine Light. Torque downpipe bolts to 30–35 ft-lb.

Final Mechanical Checks and Fluid Refill

Before firing the engine, double-check every connection.

1. Visually Inspect

Check that no tools, rags, or loose parts remain in the engine bay. Ensure wiring and vacuum lines are not pinched or contacting exhaust manifolds. Verify all clamps are tight.

2. Refill Engine Oil and Coolant

Fill engine with the recommended oil (e.g., 5W-40 full synthetic) and install a new filter. Pour coolant into the expansion tank until full. You can also pre-fill the turbo coolant jacket by pouring coolant into the supply line before final connection.

3. Prime the Turbo Oil System

To prevent dry start damage, disable the ignition (remove fuel pump relay or injector fuse) and crank the engine for 10–15 seconds. This builds oil pressure and circulates oil through the turbo bearings. Re-enable ignition and start the engine.

4. Start Engine and Check for Leaks

Start the engine and let it idle. Immediately inspect for oil, coolant, and exhaust leaks. Listen for unusual whistles or knocking sounds. The turbo may emit a slight burning smell from assembly oil – normal. If you see smoke from exhaust, it should clear after a few minutes. Check the oil pressure gauge.

Boost Gauge Installation

Monitoring boost is essential for tuning and safety. Install a mechanical boost gauge.

1. Locate a Boost Reference

Tap into the intake manifold vacuum line or use a dedicated port on the intercooler piping. Connect a vacuum/boost line to the gauge sender or directly to the gauge.

2. Route the Line

Run the line through the firewall grommet (often near the brake booster) to the gauge location. Keep it away from sharp edges. Use a nylon or copper line.

3. Install the Gauge

Mount the gauge in a pod or in-dash location. Connect the line and electrical connections (lighting). Test by revving engine – the gauge should show vacuum at idle and boost under acceleration.

Tuning Considerations and Initial Test Drive

A larger turbo demands a proper tune. Driving without correct fuel and timing maps can destroy the engine.

1. ECU Tuning

You must reprogram the ECU (Engine Control Unit) to accommodate the increased airflow. Options include: - Custom dyno tune with a standalone engine management (like Megasquirt, Haltech, or Maestro7). - Flash tuning via Cobb Accessport (for later TTS or 2.0T models) or a reputable remote tuner. - Plug-and-play chips for 1.8T (e.g., Unitronic, GIAC, APR). Contact a tuner beforehand to ensure they have a base map for GTX2867R on your engine code.

2. Boost Leak Test

Before aggressive driving, pressurize the intake system to 20 psi (using a boost leak tester) and spray soapy water on all connections. Fix any leaks. A leak can cause lean conditions.

3. Test Drive

Drive the car gently for the first 10–15 miles, varying engine speed but avoiding full throttle. This allows the turbo heat cycles and bearing break-in. After that, perform a few moderate acceleration runs (0–30 mph in 3rd gear) while monitoring boost gauge. Target boost should be 10–14 psi on wastegate spring if no boost controller is used. Increase gradually if needed.

4. Log and Adjust

Use logging software (e.g., VCDS, Cobb, or Megalog Viewer) to check intake air temperature, fuel trims, and knock activity. Adjust wastegate duty cycle or boost controller settings accordingly. Always err on the conservative side until you verify safe air-fuel ratios (AFR target: 11.5–12.0 at full boost).

Common Issues and Troubleshooting

Even with careful installation, you may encounter problems. Here are typical issues and solutions.

  • Oil Leak from Turbo Center Section: Check drain line alignment – it must be lower than the turbo outlet. If clogged, clean or replace. Also verify crush washer and banjo bolt torque.
  • Boost Creep (boost rises uncontrollably): Wastegate actuator not opening fully. Adjust rod length or upgrade to an external wastegate. Also check for exhaust restriction downpipe.
  • Lack of Power / Low Boost: Boost leak in intercooler piping or intake. Perform a smoke test. Also verify wastegate spring rating is correct for your target boost.
  • Engine Smoke After Idle: Usually oil seal issue if the drain is restricted. Also possible that coolant is leaking into oil – inspect oil dipstick for milky appearance.
  • Check Engine Light: Common with high-flow downpipe causing a catalytic converter efficiency code (P0420). Use an O2 spacer or tune defeat.

Performance Expectations and Supporting Mods

The GTX2867R flows roughly 590 hp worth of air (around 55 lb/min), but on a stock internal 1.8T or 2.0T, you should limit boost to keep the rods safe. With proper tuning, injectors (at least 550 cc for 1.8T, 1000 cc for 2.0T), fuel pump (Walbro 450 or equivalent), and a quality intercooler, expect 330–380 whp on pump gas. Ethanol blends can push 400+ whp. Torque peaks around 350–400 ft-lb.

For track or daily reliability, consider upgrading the clutch (for manual TTs), installing a catch can to reduce crankcase pressure, and adding an oil cooler if your car sees sustained high-rpm use.

Useful External References

For further details, part numbers, and community experience, consult these resources:

Conclusion

Installing a Garrett GTX2867R turbo on your Audi TT is a rewarding project that transforms the car’s performance. The key to success lies in meticulous preparation, correct line routing, and a proper engine tune. Follow each step in this guide, take your time, and double-check all connections. With the turbo installed and tuned, your TT will deliver a steep torque curve, quick spool, and excellent top-end power – making it a joy to drive both on the street and at the track.