Performance tuning has officially leveled up for Audi RS3 owners. Southside Euro is proud to announce that we now offer Unitronic Performance ECU Software for the 8Y (2022–2025) Audi RS3 with the 2.5TFSI EVO DXH engine. It’s a great development for Audi enthusiasts in Jacksonville.
With the latest Stage 2 E85 software, Unitronic delivers up to +201 horsepower and +152 lb-ft of torque over stock, bringing total output to an incredible 638HP and 534LB-FT. You’ll also get access to cutting-edge features like UniFLEX for seamless flex-fuel support and Unitronic Advanced Features (UAF) for enhanced drivability and performance control.
Best of all, thanks to UniCONNECT+, the entire tuning process can be done remotely, from your garage, straight through the OBD-II port.
Getting Started: ECU Unlock Options for the 8Y RS3
Why It’s a Big Deal for RS3 Owners
The 8Y RS3 has untapped potential from the factory. With Unitronic’s ECU software, your RS3’s 2.5L TFSI EVO DXH engine gains dramatic power and drivability upgrades, especially when paired with E85 and bolt-ons.
It’s a proven upgrade for enthusiast drivers who want more performance without sacrificing everyday reliability.
Stage 2 E85 Power Gains
This performance calibration is optimized for use with full bolt-on hardware and ethanol-based fuel. The combination results in improved turbocharger efficiency, faster throttle response, and a stronger torque curve across the rev range.
Proper fueling and cooling are essential to take full advantage of the calibration while maintaining long-term reliability.
Add-Ons: UniFLEX and Unitronic Advanced Features
Two key add-ons available with this release—UniFLEX and Unitronic Advanced Features (UAF)—give you more control and flexibility without complicating your build.
UniFLEX
With UniFLEX installed, your ECU automatically adjusts to whatever fuel blend you’re running—from 91 pump gas to full E85. No file switching. No manual input. It’s a clean solution for daily drivers and weekend track use alike.
Unitronic Advanced Features (UAF)
UAF is optional but highly functional. It adds boost-by-gear, no-lift shift, rolling anti-lag, and other configurable tools that improve drivability and response under load—especially if you drive your RS3 hard or competitively.
Both options are fully integrated and supported through the same ECU platform. Southside
Euro offers extensive experience performing Stage 2 tuning for European cars and we’ll walk you through what’s needed during your tune setup.
Book Your Tune Up With Southside Euro Now
If you’re planning to run E85 or want more out of your current setup, we’re here to make the process easy. From unlocking the ECU to dialing in the right hardware, we handle everything in-house using the latest Unitronic software and tools.
Have questions or want to schedule your tune? Reach out—we’ll walk you through exactly what your RS3 needs to perform at its best.
Schedule your appointment here.
Frequently Asked Questions
What do I need to run Stage 2 on E85?
Stage 2 requires a high-flow downpipe, upgraded intercooler, intake, turbo inlet, and an ethanol content sensor. We can supply and install all necessary components at Southside Euro.
Can I install the software myself at home?
Yes. Once your ECU is unlocked, Unitronic’s UniCONNECT+ lets you flash the tune through the OBD-II port using your laptop. We offer full setup support if needed.
What is UniFLEX and should I use it?
UniFLEX enables automatic adaptation to any ethanol blend—from 91 octane to full E85. It’s ideal if you want flexibility without switching maps or reflashing the ECU.
Will ECU tuning affect how my RS3 drives day to day?
Unitronic software maintains factory-like drivability under light throttle while improving throttle response and torque under load. It’s tuned for both street and performance use.
How do I know if my RS3 is compatible?
This software applies to 2022–2025 Audi RS3 models with the 2.5TFSI EVO DXH engine. If you’re unsure, we can verify compatibility before you schedule your tune.
