Turbocharger

At the heart of Stage III is a GTX2867R turbocharger, consisting of the latest technologies from Le Mans’ winning turbo manufacturer, Garrett Honeywell. The internally gated unit features a fully-machined, ten-blade billet compressor wheel and a dual ball bearing oil and water-cooled CHRA. APR’s Engineers spent countless hours testing turbine inlet and A/R sizes in order to decrease turbocharger lag without negatively impacting peak power. The newly developed compressor housing utilizes anti-surge porting, which greatly complements the lightning fast spool characteristics of this unit and grants APR’s Engineers the ability to deliver massive levels of torque inducing boost pressure, even in the lower RPM range.

Each turbocharger unit is assembled and clocked in house at APR with the necessary brackets to ensure proper wastegate fitment and orientation. Each wastegate is then calibrated for precise operation and control to ensure seamless integration with the expertly recalibrated OEM engine management system.

Exhaust Manifold

Attached to the turbocharger is APR’s investment-cast, super alloy, nickel-chromium-based Inconel 625 Manifold featuring APR’s Sequential Exhaust Pulse runner lengths. Unlike hand welded tubular manifolds, Inconel is a very high temperature resistant material designed to withstand extreme exhaust gas temperature changes without expanding, contracting, melting or cracking under stress. This material is typically found only at the highest levels of professional motorsport racing where reliability is essential to success.

Investment-cast Inconel features heat retention characteristics which aid in turbo response by keeping exhaust velocity high. Ensuring each exhaust pulse arrives at the collection point without collision is critical to producing lightning fast response and immediate torque delivery. Using 3D modeling and computational fluid dynamics software, APR’s Engineers designed varying short runner lengths calibrated to deliver sequential exhaust pulses without collision. A reduction in backpressure from the high flow design directly enhances power delivery.

Each manifold is investment-cast in the United States of America and machined in house on APR’s CNC machines to ensure high casting tolerances, repeatable results and strict quality control. The thick casting material reduces unwanted exhaust noise leaving behind a powerful and exotic growl.

All of these characteristics result in a manifold designed without compromise backed by a confidence inspiring lifetime warranty.

APR Stage III Software

The factory Bosch MED 9 engine management system is responsible for proper operation of the engine in all conditions. With built in compensational data for environmental variables and varying load conditions, the factory ECU is far more complex and intelligent than units found in other vehicle makes and marks.

With the significant amount of changes included in the APR Stage III Turbocharger System, APR’s Engineers spent months recalibrating the engine management system to operate smoothly as if intended by the OEM. Thanks to APR’s incredible proprietary calibration suite, data logging software and full access to the coding structure of the ECU, appropriate and intelligent changes are made to ensure flawless drivability and excellent performance without compromise.

APR’s EMCS program switching technology puts control of the ECU in your finger tips allowing you to access modes for standard pump fuel, high output race fuel and even reduced output valet modes to protect your vehicle against improper use by other individuals. This technology is patented by APR and is found nowhere else in the world. It’s Performance Without Compromise only APR can deliver!

Induction and Charge Piping

Wire reinforced, multi-ply silicone hoses provide an unrestricted path for airflow to enter and exit the turbocharger at over 1,000 kilograms per hour. The ultra rigid design ensures boost and vacuum piping will not swell or collapse causing leaks and restrictions in the induction and charge piping system supporting boost response and turbo recovery. Each hose is engineered to fit properly into the Golf R and S3 engine bay with all necessary emissions and reference ports securely affixed.

APR’s Easy-Flow Silicone Hose design features stepped mounting surfaces for smooth transitions from one pipe to another. Traditional designs simply sit on top of each other, often resulting in a disruptive airflow path. By using the stepped design, hoses fit properly without airflow restrictions, resulting in the most ideal path for moving air through the turbocharger and into the engine.

Turbo Outlet Pipe

To provide unrestricted and smooth airflow from the turbocharger to the intercooler, the APR Stage III Turbocharger System includes a cast enlarged turbo outlet pipe to properly deliver the additional airflow from the larger turbocharger.

Mass Airflow Housing

The Golf R and S3’s engine management relies on load calculations to accurately control the engine. Calculations are made by measuring airflow across the Mass Airflow Sensor and this is a critical component of the APR Stage III Turbocharger System.

The small and restrictive factory unit is removed and replaced with the much larger housing. To ensure accuracy, APR’s MAF housing is cast in the United States of America and CNC machined in house at APR to ensure repeatable results. The long, precision-machined housing features a honeycomb airflow straightener to further aid in accurately reading airflow levels. Simply enlarging the MAF housing is not permissible without accurate adjustments to the factory engine management system, which is included with APR Stage III Turbocharger System.

Oil and Coolant Lines

APR’s oil and coolant lines are specific to the Golf R and S3 Stage III System and provide years of leak free operation. The oil lines feature flexible braided stainless steel with CNC mandrel bent hard-lines for specific and clean hose routing as if intended by the OEM.

Low Pressure Fuel Pump System

The APR Low Pressure Fuel Pump System is a complete, OEM style, PWM controlled drop in fuel pump and controller solution designed to fit cleanly in the OEM location. The upgraded pump provides adequate low-pressure fuel to the APR High Pressure Fuel Pump to support the power levels produced by the APR Stage III Turbocharger System.

High Pressure Fuel Rail Valve

The factory Golf R and S3 gasoline direct injection injectors require higher than factory fuel rail pressure to achieve targeted air fuel ratios under high load, wide open throttle operation. APR’s Low Pressure Fuel Pump delivers the desired volume of fuel to the APR High Pressure Fuel Pump, which provides increased fueling headroom over the factory unit. However, the factory High Pressure Fuel Rail Valve limits maximum rail pressure below the desired level. The included APR High Pressure Fuel Rail Valve is calibrated to increase the maximum rail pressure to levels necessary for proper operation.

In doing so, APR’s able to support far higher horsepower levels than achievable on the existing APR Stage III Turbocharger Systems without the need to alter the OEM correct-spray-pattern injectors. This results in smoother part throttle operation, factory-like cold starts and fewer unburned hydrocarbons emitted from the tailpipe under all conditions compared to other fueling options.

Downpipe

The GTX2867R internally gated turbocharger unit features a Garrett five-bolt flange, which differs from the OEM turbocharger flange. To support this design, the APR Stage III Turbocharger System includes a hydroformed 3” stainless steel exhaust downturn, which mates directly to an APR Midpipe, Downpipe or Turboback Exhaust System.

Nuts, Bolts, Gaskets, Washers, Clamps, Fittings, etc

Every APR Stage III Turbocharger System includes all necessary components for a complete install.

Bracketry

No matter how small the part, each piece of the APR Stage III Turbocharger System oozes with quality evident in pieces like the Stage III's laser cut ancillary brackets and carriers.

Spark Plugs

Proper temperature range spark plugs are included with each APR Stage III Turbocharger System.