The APR Stage I ECU Upgrade is the first step towards making more power on your new Audi RS3! This simple upgrade requires no engine hardware modifications, and produces 415-435 HP with 434-464 FT-LBS of torque depending on fuel grade. Gains as high as 61-86 HP and 70-100 FT-LBS of torque are available throughout the power band, making the vehicle exceptionally quicker in all scenarios. Read more.