APR 2.9T ECU Upgrade for the Audi B9 RS5

APR is pleased to present the ultimate engine control unit (ECU) upgrade for the 2.9T EA839 engine!

APR’s ECU Upgrades are the best dollar-per-horsepower modification one can make to the 2.9T 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. Furthermore, for those looking for tuning with a limited powertrain warranty, APR Plus has you covered!

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 488-550 HP with 537-606 FT-LBS of torque depending on fuel grade. Gains as high as 75-129 HP and 89-168 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.