APR 3.0T ECU Upgrade for the Audi B9 S4, S5, and SQ5


APR is pleased to present the ultimate engine control unit (ECU) upgrade for the 3.0T EA839 engine!

APR’s ECU Upgrades are the best dollar-per-horsepower modification one can make to the 3.0T engine. The upgrades dramatically increase horsepower and torque, making for an exceptionally quicker and more exciting vehicle. This is made possible through APR’s optimization of the factory engine management system to take full advantage of the engine’s capabilities, without needing any end user adjustment. Once the ECU is unlocked, the software loads to the factory ECU through the OBD-II port, resulting in a clean and headache-free install.

Each stage includes several adjustments and features to make the driving experience more enjoyable. We’ve not only made the engine more powerful, but we’ve improved acceleration, removed the speed limiter, enabled left-foot braking or brake boosting, defaulted the auto start/stop system to “off”, properly rescaled the boost gauge, increased the stationary rev limiter, optimized thermal management and protection, designed the software to support normal bolt on modifications while not requiring any for the baseline configuration, and eliminated the need for a TCU upgrade to deliver maximum torque while still accurately reporting torque to the ECU.

APR Stage I ECU Upgrade

The APR Stage I ECU Upgrade is the first step towards making more power! This simple upgrade requires no engine hardware modifications, and produces 431-480 HP with 467-549 FT-LBS of torque depending on fuel grade. Gains as high as 85-123 HP and 103-176 FT-LBS of torque are available throughout the power band, depending on fuel grade and factory output, making the vehicle exceptionally quicker in all scenarios.

APR Stage 1 is available for 91 AKI, 93 AKI, 100 AKI, 104 AKI, and E60-E85 fuel grades in North America, and 95 RON, 98 RON, 104 RON, 108 RON, and E60-E85 in the Rest of the World.

Please note, our E85 software is not a full flex fuel program. In this mode the engine is only designed to work on E85, as found directly at the pump, including both summer and winter blends from E60-E85. Using traditional pump fuels in this mode may result in engine damage. Do not manually blend with traditional pump fuel or race fuels or use race specific barrels of E85. To ensure proper E85 content levels, APR recommends using an E85 content sensor. Before using Ethanol, educate yourself and follow our switching guide.

Dyno Testing
Select A Graph Select Graph Type
APR Calibration Report
Stage Fuel grade Max HP Max TQ Max HP Gain Over Stock Max TQ Gain Over Stock
- APR recommends and tuned with Sunoco GT 260 for 100 AKI mode and Sunoco GT 260 Plus for 104 AKI mode. Never use lower octane than specified by the mode.
- E85 software is not a full flex fuel program. In this mode the engine is only designed to work on E85, as found directly at the pump, including both summer and winter blends from E60-E85. Using traditional pump fuels in this mode may result in engine damage. Do not manually blend with traditional pump fuel or race fuels. To ensure proper E85 content levels, APR recommends using an E85 content sensor. Before using Ethanol, educate yourself and follow our switching guide.
- Max increases are based on APR's actual measured stock values and not those reported by VAG. | RON = ROW Fuel Grades | AKI = North American (RON+MON)/2 Fuel Grades.
- Reported wheel figures measured on APR's in house Dynamometer using SAEJ1349 correction and an average of multiple runs. Crank figures are estimated based on the measured wheel figures. Results may vary depending upon environmental conditions, vehicle, transmission, vehicle health, operating conditions, temperatures, fuel grade, dyno type, dyno setup, other variables and other modifications. On the dyno, this platform will see large swings in power based on intake air temperature, the gear in which it's dynoed, and transmission temperature / oil viscosity.
Stock As Reported by Audi 95 RON 349 HP 369 FT-LBS    
Stock As Measured by APR 98 RON 397 HP 395 FT-LBS    
APR Stage I 95 RON 431 HP 467 FT-LBS +85 HP +103 FT-LBS
APR Stage I 98 RON 441 HP 483 FT-LBS +95 HP +114 FT-LBS
APR Stage I 104 RON 450 HP 509 FT-LBS +106 HP +132 FT-LBS
APR Stage I 108 RON 458 HP 537 FT-LBS +116 HP +167 FT-LBS
APR Stage I E60-E85 480 HP 549 FT-LBS +123 HP +176 FT-LBS

APR ECU Upgrade Included Features

APR World Class Calibration Expertise


Tuning 101:

The 3.0T engine uses a Bosch MG1 ECU for engine management. Basically, it’s a computer that tells the engine how to operate. Tuning software, like the APR ECU Upgrade, tells the engine how to make more power. It does this by running more boost pressure, optimizing the cam shaft positions, valve lift actuation, adjusting the air/fuel ratio, advancing ignition timing, and more.

A Better Engine Management System:

The 3.0T’s ECU is incredible. Without the driver knowing otherwise, the ECU makes intelligent adjustments to the engine’s operations to keep it running smoothly. Unlike ECUs found in many other makes and models, when properly tuned, the ECU eliminates the need for custom tuning to maximize output, even when weather conditions change dramatically.

How APR Differs from the Competition:

The ECU is powerful, but extremely difficult to master. Without mastery, the ECU must be simplified, removing what makes it so desirable. The result is an incomplete product that often requires end user adjustment to maximize output in limited scenarios. On the contrary, APR’s Engineers spent years mastering the ECU to unlock its full potential. With complete access to the thousands of maps, tables and variables within, as well as a high-level understanding of how it works, APR’s Engineers were able to take advantage of everything the ECU has to offer. Power is maximized in nearly all scenarios, eliminating the need for end user adjustments. High performance operational modes are enabled and calibrated to deliver smooth daily driving, with a snappy and responsive throttle during moments of spirited driving. Mastery of the boost control system makes for an impressively predictable driving experience as the turbo spools quickly, delivering instant power, while torque-by-gear helps with traction control and protects the engine from being lugged out in tall gears. Lastly advanced high-output protection routines are enabled, allowing the ECU to make constant adjustments to airflow and fuel to cool and protect the engine, all without the driver knowing otherwise.

rabbitAuto Start Stop OFF:
We've defaulted the Auto Start Stop system to the off position. Just click the button to turn it on!

rabbitAcceleration Enhancements:
Beyond horsepower and torque enhancements, APR’s Calibration Engineers were able to increase the acceleration rate of the vehicle through other calibrations changes. Ignition delay is reduced resulting in a more responsive pedal without altering overall throttle sensitivity. Furthermore, throttle lag commonly noticed at slow speeds and while reapplying throttle has been reduced.

vmaxSpeed Limiter:
APR’s ECU upgrade increases the vehicle's top speed limiter for blistering sprints around the track or across the Autobahn without the speed limiter shutting down the fun.

Left Foot BrakingLeft Foot Braking:
APR's Left Foot Braking feature allows more control over the vehicle’s throttle. The factory equipped vehicle's throttle input is disabled while pressing the accelerator and brake at the same time. Left Foot Braking, a common motorsport driving technique, allows the driver complete control over the vehicle’s throttle and braking system, which may give the vehicle the edge it needs at the track.

ecoIncreased Fuel Economy:
APR’s Calibration Engineers paid close attention to several parameters directly related to fuel economy, especially while cruising at highway speeds. Depending on driving style and fuel quality, better miles per gallon may be achieved.

The APR Difference

APR ECU Explorer

ECUxAPR’s proprietary ECU Explorer gives APR’s Calibration Engineers unparalleled access to the vehicle’s entire engine management system. Typical commercially available data logging tools, used by most tuners, only allow logging up to 12 engine-operating variables at extremely low data rates. These tools are also limited to a small, specific list of variables. APR’s ECU Explorer is capable of logging every variable found within the ECU with far more variables logged at once, at very high data rates.

APR ECU Composer

ECUcAPR’s proprietary ECU Composer is used for altering the engine management system. With full access to every table, map and variable within the ECU, APR’s Calibration Engineers are not limited to a handful of maps as is common for most tuning companies.

APR ECU Assembly

ECUsAPR’s Electrical Engineers have the ability to alter the code structure of the ECU. Through code levels changes, APR's Engineers are able to add features to the ECU. Other changes allow higher torque limits than those achievable through only modifying calibration data or using piggyback devices as is the case for many tuners. On the highly modified end, this often allows APR to make turbo upgrades operate without the need for external manual controllers.

APR Direct Port Programming

DirectPort ProgrammingAPR’s DirectPort Programming is now available! Any APR Dealer in the world, connected to the Internet, has direct access to APR’s latest ECU upgrades for loading directly over the vehicle's OBD-II port. This completely eliminates the need to remove and open the ECU for currently available files and can be uninstalled at any time! PLEASE NOTE - This is only available once the ECU is unlocked.

Application Guide
Vehicle Engine
Audi S4 (B9 and B9.5 / 8W) 3.0 TFSI EA839
Audi S5 (B9 / 8W) 3.0 TFSI EA839
Audi SQ5 (B9 / 80) 3.0 TFSI EA839
Stage Price Exc. VAT Price Inc. VAT
- Pricing: Please contact an APR Importer for pricing outside the USA.
- 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. An APR dealer can check availability in person, or over the phone if the ECU boxcode/revision is known.
APR Stage I ECU Upgrade