Installing a turbocharger is one of the most effective ways to transform your GLI’s driving character, and the APS RaceTurbo 62mm Turbo kit is a well-regarded option for enthusiasts seeking a noticeable power increase with reliable daily-driver dynamics. This guide provides a comprehensive, step-by-step approach to installing this turbo on your GLI, covering everything from tools and safety preparation to the final startup and post-installation checks. Whether you are an experienced home mechanic or a motivated first-time installer, careful attention to detail during each phase will help ensure a smooth, leak-free, and successful upgrade.

Tools and Materials Needed

Before starting, assemble all required tools, replacement parts, and consumables. Having everything within reach reduces downtime and the risk of forgetting a critical step.

Required Tools

  • Metric socket set (8mm, 10mm, 12mm, 13mm, 15mm, 18mm, 22mm)
  • Combination wrenches (10mm, 12mm, 13mm, 15mm, 18mm)
  • Torque wrench (ft-lb and in-lb ranges)
  • Flat-blade and Phillips screwdrivers
  • Long-reach needle-nose pliers
  • 6mm Allen key set
  • Pick set (for removing old gasket material)
  • Jack and jack stands (minimum 2-ton capacity)
  • Shop rag and brake cleaner
  • Threadlocker (medium-strength, e.g., Loctite 242)
  • High-temp anti-seize compound (for exhaust fasteners)
  • Coolant drain pan
  • Oil drain pan

APS RaceTurbo 62mm Turbo Kit Components

Verify that your kit includes:

  • APS RaceTurbo 62mm turbocharger assembly
  • Turbo-to-manifold gasket
  • Turbo-to-downpipe gasket
  • Oil feed line (braided stainless steel)
  • Oil return line (with appropriate gaskets)
  • Coolant feed and return lines (if applicable to your GLI model)
  • Intercooler piping kit (hot and cold side)
  • Hose clamps and couplers
  • Mounting hardware bolts, washers, lock washers
  • Turbo blanket (optional, recommended for heat management)

Additional Consumables

  • Fresh engine oil and filter
  • Coolant (type specified for your GLI)
  • Gasket sealant (Permatex copper or equivalent)
  • Crush washers for oil drain plug
  • Duct tape or zip ties for marking hoses

Safety and Preparation

Turbocharger installation involves hot surfaces, flammable fluids, and heavy components. Work in a well-ventilated area and wear safety goggles and gloves throughout the process.

  1. Disconnect the battery – remove the negative terminal cable to eliminate any risk of short circuits or accidental engine cranking while you work near fuel and oil lines.
  2. Lift and secure the vehicle – jack up the front of the GLI and place it on jack stands at the factory lift points. Never rely solely on a hydraulic jack. Ensure the car is stable before crawling underneath.
  3. Let the engine cool completely – the exhaust manifold and turbo housing remain hot for hours after driving. A cool engine reduces the risk of burns and makes gasket removal easier.
  4. Drain the engine coolant – locate the radiator drain valve or lower radiator hose and drain coolant into a clean pan. You will need to disconnect coolant lines from the turbo later, so draining prevents a messy spill.
  5. Drain the engine oil – remove the oil drain plug and let the oil drain completely. Reinstall the plug with a new crush washer. Fresh oil will be added after installation, so draining now avoids contamination.
  6. Remove any under-engine covers – the splash shield and/or belly pan must come off to access the turbo and oil/coolant lines. Set the fasteners aside in a labeled bag.

Removing the Factory Turbocharger

If your GLI is equipped with a stock turbo (often a smaller BorgWarner or Garrett unit), you must remove it carefully to avoid damaging surrounding components.

Step 1: Disconnect Intake and Charge Air Piping

Remove the air filter housing and intake boot leading to the turbo inlet. Unclamp the charge air pipe from the turbo outlet and the intercooler inlet. If your GLI has a factory diverter valve, disconnect its electrical connector and vacuum line, then set the pipe aside.

Step 2: Remove the Exhaust Downpipe

Unbolt the downpipe from the turbo outlet flange (usually three or four bolts). The downpipe may also be bolted to a bracket near the firewall or transmission. Use a penetrating spray like PB Blaster on rusty fasteners and allow it to soak for 10 minutes. Once free, lower the downpipe out of the way. Do not fully remove it yet – you may need to wiggle it past the subframe or control arm.

Step 3: Disconnect Oil and Coolant Lines

Locate the oil feed line running from the engine block or filter housing to the turbo. Use a line wrench to loosen the banjo bolt or flare nut. Similarly, disconnect the oil return line (usually a rubber hose with a spring clamp) from the turbo return port. For coolant, unbolt the feed and return hard lines or hoses from the turbo water jacket. Have rags ready to catch residual fluid.

Step 4: Remove the Turbo from the Exhaust Manifold

Support the turbo with one hand and unbolt the turbo from the exhaust manifold. Typically, there are four or five nuts on studs. A flexible ratchet or a combination wrench makes the job easier. Gently wiggle the turbo off the studs and lower it out from above or below, depending on your GLI generation (Mk6, Mk7, etc.). Be careful not to drop it on the steering rack or subframe.

Step 5: Clean the Manifold and Drain Tubes

Once the factory turbo is out, scrape off any leftover gasket material from the manifold flange. Use brake cleaner and a plastic scraper – avoid scratching the sealing surface. Inspect the oil drain tube and manifold threads for damage. Replace any bent or stripped studs before proceeding.

Installing the APS RaceTurbo 62mm Turbo

With the engine bay prepared and the manifold clean, you are ready to install your new turbocharger. This section assumes you have a 62mm compressor wheel unit with a standard T25 or T3 flange pattern – confirm compatibility with your GLI’s exhaust manifold. Many kits include an adapter or a new manifold; adjust steps accordingly.

Step 1: Pre-Lube the Turbo Bearings

Before final assembly, pour a few tablespoons of clean engine oil into the oil feed port on the turbo. Rotate the compressor wheel by hand several times to distribute the oil through the bearings. This critical step prevents dry-start damage and ensures immediate oil pressure when the engine fires.

Step 2: Mount the Turbo to the Exhaust Manifold

Install a new turbo-to-manifold gasket (often a metal multi-layer sheet). Apply a thin film of high-temp anti-seize to the manifold studs or bolt threads. Carefully lower the APS turbo onto the studs, aligning the oil drain flange with the return line. Tighten the nuts in a crisscross pattern to seat the gasket evenly. Torque to the manufacturer’s specification (typically 18–20 ft-lb for M8 studs).

Step 3: Attach the Oil Feed and Return Lines

Screw the new APS oil feed line into the turbo’s feed port. Use a new copper or aluminum crush washer on the banjo fitting if applicable. Torque the banjo bolt to the specified value (commonly 14–16 ft-lb). Then reconnect the oil return line – a silicone hose with a spring clamp works well. Ensure the return line is routed downhill to promote gravity drainage. Secure the line with a clamp that does not pinch or kink the hose.

Step 4: Connect Coolant Lines

Attach the coolant feed and return lines to the turbo’s water jacket fittings. Use new gaskets or O-rings supplied with the kit. Tighten the banjo bolts or flare nuts to specification (typically 12–15 ft-lb). Double-check that the coolant hoses are not contacting the exhaust manifold or hot-side piping.

Step 5: Install the Downpipe and Intercooler Piping

Bolt the downpipe to the turbo exhaust outlet with a new gasket. Use anti-seize on the bolts and torque to 30–35 ft-lb. If the downpipe has a flexible section, support it with a transmission bracket. Next, connect the intercooler piping – start with the hot side (turbo outlet to intercooler), then the cold side (intercooler to throttle body). Use the provided silicone couplers and T-bolt clamps. Tighten clamps firmly but do not overtighten or they can cut the silicone.

Post-Installation Checks and Reassembly

Before lowering the car and starting the engine, perform these verification steps.

  • Tighten all clamps and fasteners – go back over every connection: turbo-to-manifold, downpipe, oil/coolant fittings, intercooler pipes, and intake boot.
  • Reinstall heat shields – factory heat shields protect the brake lines and wiring. If the APS kit requires trimming, use tin snips carefully to avoid sharp edges.
  • Reconnect the battery – attach the negative terminal, then double-check that no tools or loose rags are left near the serpentine belt or turbo.
  • Refill engine oil – add fresh oil of the correct weight and capacity (consult your owner’s manual). Do not overfill.
  • Refill coolant – use the proper coolant type (G12, G13, or equivalent). Fill the expansion tank to the “MAX” line, then start the engine with the radiator cap off to purge air.

First Startup and Air Purge Procedures

After reassembly, follow this startup routine to protect the new turbo and other components.

  1. Prime the oil system – before starting the engine, disable the fuel pump (pull the fuel pump fuse or relay) and crank the engine for 5–10 seconds. This circulates oil through the turbo bearings without combustion pressure. Re-enable the fuel pump after priming.
  2. Start the engine – let it idle at a moderate RPM (around 1000–1200) for about 30 seconds, then allow it to idle normally. Listen for any unusual rattles or whistles. A slight spooling sound from the new turbo is normal, but a metallic scraping indicates a clearance issue.
  3. Check for leaks – visually inspect all oil, coolant, and intake connections. Pay special attention to the banjo fittings and the oil return line. Use a flash to see the back of the turbo. Small drips should be addressed immediately.
  4. Bleed the cooling system – with the engine running and the heater set to maximum, watch for bubbles coming through the open coolant reservoir. Rev the engine gently to help purge air. Once no more bubbles appear and the coolant level stabilizes, replace the cap.
  5. Monitor oil pressure and temperature – if your GLI has an oil pressure gauge, verify that pressure stays within spec at idle and revs. If you do not have a gauge, consider installing one before pushing the car hard.

First Test Drive and Break-In

After confirming no leaks and stable idle, take the car for a gentle test drive.

  • Drive miles 0–50 – keep boost below 5 psi (if your wastegate allows). Do not exceed 3,000 RPM. This seats the oil seals and lets the turbo bearings wear in smoothly.
  • Drive miles 50–200 – gradually increase boost to about 10 psi. Vary engine speed and avoid sustained high load. Perform several 10-second pulls at partial throttle to ensure the wastegate cycles properly.
  • After 200 miles – change the oil and filter. Small metal particles from initial break-in can circulate, so a fresh fill protects the turbo and engine.
  • Tuning requirement – the APS RaceTurbo 62mm is much larger than the stock unit. To avoid dangerously lean conditions, a custom tune from a reputable shop (e.g., Unitronic, APR, or a local tuner) is mandatory. The tune should include specific fuel and boost maps for the 62mm compressor. Driving without a proper tune can cause severe engine damage.

Common Mistakes and Troubleshooting

Even experienced mechanics encounter pitfalls. Here are issues to watch for and how to address them.

Oil Leaks at the Feed Line

Symptom: Fresh oil dripping from under the turbo within minutes of startup.
Cause: Loose banjo bolt, missing or damaged crush washer, or incorrect fitting orientation.
Solution: Torque the banjo bolt to spec and use a new washer. Check that the feed line does not touch the exhaust manifold, which can melt the line over time.

Boost Leaks

Symptom: Turbo spools loudly but car feels sluggish; boost gauge reading lower than expected.
Cause: Loose intercooler connection, split coupler, or unmounted wastegate actuator arm.
Solution: Perform a smoke test or pressurized boost leak test. Tighten or replace the leaking component. On the APS turbo, verify the wastegate actuator bracket is secure.

Excessive Smoke from Exhaust

Symptom: White or blue smoke at idle or on deceleration.
Cause: Overfilled oil, restricted oil drain line, or defective turbo oil seal.
Solution: Check oil level – drain excess if needed. Inspect the oil drain hose for kinks or blockages. If the drain is clear and the problem persists, the turbo may have a defective seal; contact the manufacturer for warranty evaluation.

Hesitation or Surging Under Load

Symptom: Car bucks or hesitates when boost rises above 10 psi.
Cause: Incorrect tune, failing fuel pump, or boost control issue.
Solution: Review the tune with your tuner. Verify that the wastegate duty cycle is correctly mapped. Upgrade the high-pressure fuel pump if you are using a larger turbo on a direct-injection GLI.

Performance Expectations and Supporting Mods

The APS RaceTurbo 62mm is capable of supporting 350–420 whp on pump gas with a well-matched tune. To fully realize its potential, consider these supporting upgrades:

  • High-flow intercooler – a larger bar-and-plate core keeps intake air temperatures low.
  • 3-inch turbo-back exhaust – reduces backpressure and spool time.
  • High-pressure fuel pump or injectors – provide enough fuel volume to match the increased air flow.
  • Cold-air intake – feeds the turbo with denser air.
  • Short-ram intake manifold – improves high-RPM flow on some GLI engine variants.

For more detailed installation tips, refer to the official APS RaceTurbo installation manuals and the GolfMK6 forums for platform-specific advice. A factory service manual for your GLI (available through VW ERWIN) is an invaluable resource for torque specifications and electrical diagrams.

Final Thoughts

Installing the APS RaceTurbo 62mm turbo on your GLI is a rewarding project that can dramatically elevate the driving experience. By following this detailed guide, you can avoid common pitfalls and achieve a reliable, high-performance setup. Remember to take your time, double-check every connection, and invest in a professional tune tailored to your hardware. With careful execution and proper break-in, your GLI will deliver strong, consistent power for many miles to come.