Preparation Before Installation

Before you begin installing the APR R8 Twin Turbo Kit, thorough preparation is essential to avoid costly mistakes and ensure a smooth workflow. Start by parking the vehicle on a level, well-ventilated surface with ample lighting. Disconnect the battery negative terminal to prevent any electrical shorts or accidental airbag deployment during the process. Read the entire APR installation manual that ships with the kit; pay special attention to torque specifications, fluid capacities, and any model-specific notes for your Audi R8 generation (either the 4.2L V8 or the 5.2L V10). If possible, review online build threads and installation videos from experienced enthusiasts to anticipate challenges. Drain the cooling system and engine oil before starting, and have a clean work area clear of debris. It is also wise to set aside at least two full days for the installation if you are a skilled DIY mechanic, or plan for professional shop time if you lack experience with forced induction systems.

Essential Tools and Equipment

Having the correct tools at hand will save hours of frustration. Beyond the standard socket set, torque wrench, screwdrivers, pliers, and wrenches listed previously, add the following to your toolkit:

  • Torque angle gauge – Many fasteners on the R8 require tightening to a specific angle rather than a set pound-foot value.
  • Fuel line disconnect tools – The high-pressure fuel system uses quick-connect fittings that require a specialized tool to release without damage.
  • Pry bars and trim removal tools – The R8’s body panels and interior trim are fragile; proper tools reduce risk of cracking clips or paint damage.
  • Digital calipers – Useful for checking clearances and verifying gasket thickness during assembly.
  • Leak-down tester or vacuum pump – Post-installation you will need to pressure test the charge air system and cooling circuits.
  • Fluid evacuation pump – Makes draining and refilling coolant and oil much cleaner than removing the drain plugs alone.
  • Thread locker (Loctite 243 or equivalent) – Many turbo mounting bolts and exhaust studs require medium-strength thread locker to withstand vibration.
  • OEM replacement gaskets and seals – The kit may include most gaskets, but having extra turbo inlet and outlet seals on hand can save a trip to the parts store.

Also stock up on rags, gloves, safety glasses, and a fire extinguisher rated for fuel and electrical fires. Ensure your torque wrench has been calibrated within the past year; a small error in torque on turbocharger fasteners can lead to boost leaks or catastrophic failure.

Step-by-Step Installation Guide

Step 1: Remove Stock Components

Begin by relieving fuel system pressure: locate the fuel pump fuse and run the engine until it stalls, then crank it once more. Remove the engine cover, airboxes, and intake ducts. On V10 models, the intake manifold is large and will need to come off to access the exhaust manifolds and turbo mounting points. Label every vacuum line and electrical connector with masking tape and a marker. Photograph the original routing of hoses and wiring before disconnecting anything. Use a lift or high-quality jack stands rated for the R8’s weight (approximately 3,800 lbs). Remove the under-tray and belly pans. Drain the engine oil, coolant, and if equipped, the intercooler coolant circuit. Disconnect the exhaust system from the catalytic converters back to the mufflers. You may also need to remove the front bumper and headlight assemblies on certain years to access the intercoolers and charge air piping.

Step 2: Install Turbochargers and Mounting Brackets

The APR kit’s turbochargers mount in the rear engine bay area, above the transmission bellhousing. First, install the APR-supplied turbo support brackets to the engine block using new OEM bolts. Apply a dab of medium-strength thread locker to each bolt and torque to the specification in the manual (typically 18–22 lb-ft). Carefully position each turbocharger onto its bracket, ensuring the oil return line flange is oriented downward. Use supplied gaskets between the turbo and the exhaust manifold flange. Tighten the four retaining nuts in a star pattern to 25 lb-ft. Do not fully tighten the V-band clamps on the compressor outlet yet—wait until the charge air piping is aligned in a later step.

Step 3: Connect Oil and Coolant Lines

Locate the oil supply banjo bolts and crush washers; the APR kit typically feeds oil from a port near the oil filter housing. Assemble the -3AN braided oil supply lines with the included fittings, being careful not to cross-thread. Torque the banjo bolt to 14 lb-ft. The oil return lines are usually larger (-10AN) and must be routed to the oil pan. You may need to remove the oil pan and drill/tap a 1/2-inch NPT return port in the side of the pan above the oil level. Weld or epoxy the supplied bung in place, then connect the return line with high-temperature silicone hose and screw clamps. For coolant, use the APR’s adapter hoses that splice into the heater core circuit or the engine’s water pump. Purge air from the system by loosening vent screws on the water pipes while filling with a 50/50 G12+ mix. All lines must be secured away from hot exhaust surfaces using zip ties or heat-resistant sleeve.

Step 4: Install the Upgraded Intake and Intercooler System

APR provides a dual-cone air filter setup that replaces the factory airbox. Fit the filters over the MAF housing and tighten the hose clamps. Route the charge air pipes from the turbo compressor outlets to the intercooler cores (typically two bar-and-plate style intercoolers mounted behind the front bumper). Use silicone couplers and T-bolt clamps; ensure each connection is fully seated and that the clamps cannot contact the radiator fins. Install the supplied diverter or blow-off valves (APR often recommends recirculating valves for low-boost street applications). Secure the intercooler brackets to the crash bar or radiator support and tighten the nuts to 8 lb-ft.

Step 5: Attach Exhaust Components

The APR kit includes downpipes that replace the factory catalytic converters. Coat the flange gaskets with a thin layer of anti-seize compound. Bolt the downpipes to the turbo exhaust outlet studs with new locknuts and torque to 30 lb-ft. Connect the downstream exhaust section using the APR-supplied mid-pipe with high-flow metal-core catalytic converters. Reuse the factory exhaust hangers but add new rubber isolators if they are over five years old. Check that the exhaust does not contact the chassis or the transmission shift rods when the engine is at operating temperature. Torque the remaining V-band clamps and tighten all heat shield brackets.

Step 6: Final Assembly and Electrical Connections

Reinstall the intake manifold with new gaskets and torque the bolts in the specified sequence. Connect the fuel injectors and main harness connectors. If the kit includes a boost controller or MAP sensor signal line, follow the APR wiring diagram to splice into the ECU harness at the proper pins. Reconnect the battery and refill all fluids: engine oil (5W-40 synthetic recommended), coolant, intercooler coolant, and power steering fluid if needed. Prime the oil system by turning the engine over with the fuel pump relay removed for 10 seconds until the oil pressure gauge registers. Reset the battery memory by performing the idle-relearn procedure described in the APR manual (typically key-on, engine-off for 30 seconds, then start and idle for 10 minutes without touching the accelerator).

Post-Installation Checks

After the engine has run for a few minutes and reached operating temperature, perform these critical checks:

  • Leak check – Use a boost leak tester (attach to the intake pipe and pressurize to 15 psi) while listening for hissing. Soapy water on all connections reveals bubbles for small leaks. Rectify any leaks before driving.
  • Torque re-check – With the engine cold, re-torque all turbocharger nuts, exhaust manifold bolts, and intercooler brackets. Thermal cycling often loosens initial fasteners.
  • Bleed the cooling system – Run the engine with the coolant reservoir cap off and the heater on maximum. Watch for air bubbles. Top off coolant as needed when the thermostat opens.
  • Listen for unusual noises – Metallic rattles indicate a loose heat shield or a turbocharger contacting the chassis. Whistling sounds from the intake may point to a vacuum leak. Clicking from the engine bay could mean an improperly routed oil return line is hitting the driveshaft.
  • Monitor oil pressure and temperature – Cold oil pressure should be around 80–90 psi at 2,000 rpm; at idle after warm-up, 20–30 psi is typical. Turbocharger oil temperatures should not exceed 250°F during sustained driving.

Take the vehicle for a gentle test drive, staying below 3,500 rpm and 5 psi of boost for the first 100 miles to allow the turbochargers to break in. Listen for any changes in engine sound and monitor all gauges. After the break-in period, change the engine oil and filter to remove any metal particles from the initial wear-in.

Tuning the APR R8 Twin Turbo Kit

Tuning is arguably the most important aspect of extracting maximum safe power from the APR kit. The stock ECU (Bosch MED17 or similar) is not calibrated for forced induction on the R8; untuned operation can lead to detonation, excessive EGTs, and catastrophic engine damage. APR offers its own plug-and-play flash tunes that have been extensively dyno-tested for the kit. For custom tuning, use software platforms such as EFISource or HP Academy to learn fuel and timing mapping for high-boost V10s. Professional tuners often prefer standalone systems like MoTeC M1 for full control, but this is a significant investment. Regardless of the route, ensure the tuner performs a base calibration at low boost (5–7 psi) before advancing to the kit’s full potential of 10–14 psi. Key parameters to monitor during tuning are knock retard, wideband lambda (target 0.78–0.80 lambda under full boost), and turbocharger shaft speed (if using a speed sensor). Regularly check for surge or compressor stall during part-throttle transitions. A good tune will provide linear power delivery without abrupt spikes in boost. Consider upgrading the fuel system with AEM high-flow pumps or injectors if you plan to exceed 600 wheel horsepower.

Maintenance Tips for Longevity

The APR R8 Twin Turbo Kit can last many tens of thousands of miles if maintained properly. Follow these guidelines:

  • Oil changes – Reduce your interval to every 3,000 miles (or 6 months) using a high-quality full synthetic oil with a high flash point, such as Motul 300V or Castrol Edge 5W-40. Turbochargers heat oil more severely than naturally aspirated engines; degraded oil causes carbon buildup in the center cartridge bearings.
  • Air filters – Inspect the APR conical filters every service. Clean or replace them if they appear dirty. The R8’s engine bay can ingest road debris through wheel-well gaps. A dirty filter reduces efficiency and can cause a rich condition.
  • Cooling system – Flush and refill the coolant every two years. The extra heat load from turbos accelerates coolant breakdown. Check the intercooler system separately: drain and replace the water/meth mixture (if using a water-to-air setup) annually. Verify that the auxiliary electric pumps are working by feeling for flow through the hoses after a hard run.
  • Turbocharger inspection – Every 15,000 miles, remove the intake ducts and visually inspect the turbine wheels for signs of rubbing (scratches on the housing) or excessive shaft play. Lateral play under 0.005 inch is normal; radial play over 0.010 inch indicates a failing bearing. Listen for a “hiss” or “warble” from the turbos at idle that may correspond to a worn bearing cage.
  • Vacuum and boost hoses – Silicone hoses do not last forever in an engine bay that sees 200°F+ under the cowl. After two years, inspect all boost and vacuum lines for cracking, swelling, or heat embrittlement. Replace with high-temperature silicone rated to 350°F. Pay special attention to the hoses near the exhaust manifolds; move them away with heat shielding if necessary.
  • Hardware re-torque – At each oil change, re-torque the turbo mounting nuts and exhaust flange bolts. The constant expansion and contraction can loosen fasteners. Use a torque wrench that reads in inch-pounds for small fasteners to avoid overtightening.

Finally, document every maintenance action with dates and mileage. The APR kit retains value when records are clear. If you ever sell the car, potential buyers (especially enthusiasts) will pay a premium for a well-documented, professionally maintained forced induction system.

Conclusion

Installing the APR R8 Twin Turbo Kit can transform your Audi R8 from a grand tourer into a true supercar-slaying machine, delivering exhilarating power across the rev range. But the difference between a successful, reliable setup and a problematic one lies in the details: meticulous preparation, correct tooling, careful assembly, a proper break-in, and ongoing maintenance. By adhering to the best practices outlined in this guide, you ensure that your investment in speed is matched by durability. Whether you’re a veteran of forced induction builds or a first-time turbo installer, take the time to study the APR documentation, engage with the community on forums such as Audizine, and consider professional help for the tuning and final quality checks. With the right approach, your APR twin-turbo R8 will provide years of exhilarating driving and unwavering reliability on both street and track.