APR 1.8 TSI/TFSI K04 Turbocharger System


APR 1.8 TSI/TFSI K04 Turbocharger System
APR 1.8 TSI/TFSI K04 Turbocharger System
APR 1.8 TSI/TFSI K04 Turbocharger System
APR 1.8 TSI/TFSI K04 Turbocharger System
APR 1.8 TSI/TFSI K04 Turbocharger System


APR 1.8 TSI/TFSI K04 Turbocharger System


APR 1.8 TSI/TFSI K04 Turbocharger System

APR's Transverse 1.8 TSI Audi S3 and VW Golf R Engine Conversion Packages will upgrade your current factory rated 158hp and 180lb-ft Transverse 1.8 TSI Engine with all of the necessary OEM components from the European Audi S3 and VW Golf R and meticulously recalibrated Engine Management to produce 330 horsepower and 335lb-ft of torque on 98 RON gas.

APR's engineers have expertly recalibrated the engine management system to allow for a broad torque curve which results in a smooth linear pull throughout the power band. Keeping the track enthusiast in mind, this conversion package will not result in overpowering of the driveline but will allow for smooth acceleration to easily maintain control while cornering.

APR Modified K04 Compressor Cover

APR Compressor Overview

The Borg Warner K04 turbocharger selected by VAG engineers is perfectly sized for the 1.8 liters of displacement to allow for stout horsepower numbers as the RPMs increase with no dramatic fall off as redline approaches. This ensures plenty of power in the high RPMs for continued acceleration in the straights and positioning at the healthiest portion of the power band after corner exit.

Compact, Stealthy & Reliable Design

One of the greatest benefits to the APR K04 turbocharger system is its simple, yet elegant design. APR's CNC machined direct compressor recirculation port on the OEM compressor cover significantly reduces engine bay clutter and saves the end user from the hidden costs of purchasing extra throttle body pipes, hoses, clamps and DV mounts for recirculating boost pressure. The compact design also removes extra charge piping volume to allow for lightning fast boost response and less locations for boost leaks. Furthermore, charge air pressure is directed directly at the compressor wheel which helps keep the turbo spooled upon lifting the throttle, minimizing turbo lag.

The OEM k04 turbocharger features a turbo muffler designed to reduce turbocharger sound in the cabin that also creates a restriction in the boost pressure delivery stream. APR removes the turbo muffler not only to enhance the sound of the turbocharger, but also to smooth the airflow across the previously baffled muffler section. A clean and simple CNC flange developed by APR's Engineering Team is bolted directly to the compressor cover in place of the OEM turbo muffler. A long mounting surface provides an excellent slip proof surface for mounting the silicon discharge hose and an o-ring between the flanges ensures a life of leak proof operation.

The K04 turbocharger was originally designed for an FSI engine, and as such, some items not required for the new TSI engine are present. The compressor cover features a port used in the FSI's PCV system, however on the TSI, this same port is located higher up on the intake tubing. APR has provided a gasket sealed laser cut port cover to block off this part and ensure no unmetered air leaks into the system. The design is clean and simple and never requires maintenance.

APR's Patented EMCS Technology

Featuring APR's Patented EMCS program switching functionality and DirectPort Programming, APR's Engine Management Calibration for this conversion package allows for a range of Octane and situation specific calibrations to be installed simultaneously on your vehicle's ECU. These programs and features are able to be cycled through via your existing factory cruise control and activated in less than 20 seconds. You will be able to choose 1 to 4 Programs listed below. You will also be able to add APR Security Lockout, APR Fault Code Erase and APR Anti-Theft features.

Program Mode* Peak HP Peak TQ Largest HP Gain Over Stock Largest TQ Gain Over Stock Speed Limit
*It is essential to ensure your vehicle is filled with at least the minimum octane rating for each Performance Calibration when activating the program.
¹Figures measured using APR APR Carbon Fiber Intake and APR Downpipe Exhaust System.
Stock - As reported by VW/Audi 158 HP 180 LB-FT - - 127 MPH
Stock - As measured by APR 186 HP 206 LB-FT - - 127 MPH
APR 95 RON Unmeasured Unmeasured Unmeasured Unmeasured Unlimited
APR 98 RON¹ 330 HP 335 LB-FT 151 HP @ 6100 RPM 140 LB-FT @ 5600 RPM Unlimited
APR 100 RON Unmeasured Unmeasured Unmeasured Unmeasured Unlimited
APR 104 RON Unmeasured Unmeasured Unmeasured Unmeasured Unlimited
APR Valet Limited Output Limited Output Limited Output Limited Output 70 MPH



APR provides all hardware and software needed to ensure a complete install. All items which can be preassembled on the turbocharger come preassembled by APR. The APR K04 turbocharger system consisting of the following:

  • APR EMCS Software
  • APR Modified OEM K04 Turbocharger with Billet Compressor Wheel, Stainless Steel Exhaust Manifold, N75 Solenoid and Wastegate Actuator
  • APR CNC Turbo Outlet Flange
  • APR Turbo to Turbo Outlet Flange O-Ring
  • APR Turbo to Turbo Outlet Screws (3x)
  • APR Turbo Outlet Silicon Hoses
  • APR Turbo Outlet Hose Clamps (2x)
  • APR CNC Compressor Cover DV Mounting Flange
  • APR Turbo to DV Mounting Flange O-Rings (2x)
  • APR Turbo to DV Mounting Flange Screws (3x)
  • OEM DV Mounting Screws (3x)
  • OEM DV Mounting Screw Lock Washers (3x)
  • APR Laser Cut PCV Port Cover
  • APR PCV Port Cover Gasket
  • OEM PCV Port Cover Screws (2x)
  • OEM PCV Port Cover Screw Lock Washers (2x)
  • OEM Turbo Manifold Gasket
  • OEM Turbo Manifold Nuts (4x)
  • OEM Downpipe Studs (4x)
  • OEM Downpipe Nuts (4x)
  • OEM Downpipe Gasket
  • OEM EVAP Line One Time Use Hose Clamps (3x)
  • OEM Oil Return Line Gasket (2x)
  • OEM Oil Feed Line Washers (2x)
  • OEM Coolant Feed Line Washers (2x)
  • OEM Coolant Return Line Washers (2x)

OEM Appearance

APR's S3 K04 Turbocharger Conversion System is constructed from OEM parts and appears OEM. It's easy to install and 100% reversible. Every OEM part is fully Plug and Play:

  • Exhaust (Upgrade Highly Recommended)
  • Intercooler (Upgrade Highly Recommended)
  • Intake (Upgrade Highly Recommended)
  • Diverter Valve
  • Positive Crankcase Ventilation Lines
  • EVAP Lines
  • Coolant Lines
  • Oil Lines
  • Turbo Support Brace

APR K04 Compressor Cover vs
OEM K04 Compressor Cover

Dyno Performance

93 Octane Dyno Chart

Installation can be performed at MF Auto, Inc and all parts necessary for the installation except for fluids are included. For best results APR highly recommends the APR downpipe exhaust system, APR APR Carbon Fiber Intake System and APR Intercooler System.

Golf R/S3 K04 Conversion - Software Included
Vehicle Engine Transmission* Drivetrain
*Transmission upgrades are highly recommended with this upgrade.
Audi A3 8P 1.8 TSI All All
Audi TT MKII 1.8 TSI All All
VW Golf MKVI 1.8 TSI All All
VW Magatron 1.8 TSI All All
VW Passat B6 1.8 TSI All All
VW Passat B7 1.8 TSI All All
VW Passat CC 1.8 TSI All All
VW Sagitar 1.8 TSI All All
Seat Altea 1.8 TSI All All
Seat Leon 1P 1.8 TSI All All
Seat Toledo MKIII 1.8 TSI All All
Skoda Octavia II 1.8 TSI All All
Skoda Superb II 1.8 TSI All All
Skoda Yeti 1.8 TSI All All

To ensure software is ready or available for each vehicles’ ECU box code and revision, please check with APR prior to scheduling appointments!


Turbocharger Loyalty Program

We’re pleased to announce the turbocharger upgrade path just got a little easier for our loyal APR customers. If you’ve purchased an APR ECU Upgrade and want to upgrade to one of our turbocharger systems, you can take advantage of fantastic savings! It’s our way of saying “thank you” for enjoying our ECU Upgrades before stepping up to the big leagues! To see the savings, look over the pricing tiers below. Pricing also includes a fully loaded APR ECU, where applicable!

Please Note: An APR Dealer MUST check software availability and compatibility before purchase.

APR K04 Turbocharger System
System Part APR Loyalty
Discount Price²
APR K04 Turbocharger System - Includes Software* T2100010 $2,299.99 $2,599.99
Pricing - Software Only
Stage Minimum Requirements Price
- Pricing: Please contact for pricing outside the USA.
- Program Switching: A fully loaded ECU includes up to 4 program modes (stock mode, performance modes, valet, etc), as well as fault code erase, security lockout and anti-theft depending on availability and ECU compatibility.
- Availability and ECU Compatibility: Stages, programs, and features may not be available for all ECUs.
- ECU Revision Notice: Multiple ECU revisions exist for each platform. APR software may be temporarily unavailable when factory updates are applied. We can check availability in person, or over the phone if the ECU boxcode/revision is known.
APR Stage I ECU Upgrade (Existing APR ECU Upgrade Customer) Genuine Borg Warner K04-64 Turbocharger and See Requirements and Recommendations Above $499.99
APR Stage I ECU Upgrade (New APR ECU Upgrade Customer) Genuine Borg Warner K04-64 Turbocharger and See Requirements and Recommendations Above $899.99
- Add APR EMCS Program Switching (Fully Loaded) None $149.99

How to purchase

APR Dealer

Please note vehicle manufacturers issue many ECU part numbers and revisions throughout their vehicle lineup. As such, some ECUs may be temporarily unavailable as new parts and/or revisions are released. If the vehicle’s ECU part number and revision is known, availability can be checked at any APR Dealer.