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Unitronic ECU Performance Software is NOW AVAILABLE for the 8Y.2 (2025+) Audi RS3 equipped with the 2.5TFSI EVO DXH engine in North America (NAR) with UniFLEX (Flex Fuel) and Unitronic Advance Features (UAF) Add-Ons. With testing and validations completed, power output is increased by up to +201HP / +152LB-FT with Unitronic Stage 2 Performance Software using E85 fuel, for a maximum of 638HP / 534LB-FT*.
Once the MG1CS164 ECU is unlocked, users can tune their vehicles directly through the OBD-2 port** within minutes, from the comfort of their own home or garage with UniCONNECT+. Support for MY25+ RS3 and Cupra Formentor VZ5 DNWx engines found in Rest-of-World (RoW) markets is coming soon!
Building off of our extensive experience with 2.5TFSI (DXH / DNW / DAZ) engines across the globe, Unitronic's all-new Performance Software offerings, along with its industry-leading UniFLEX and Advanced Feature (UAF) Add-Ons, will deliver an unmatched level of performance, drivability and customizability for 8Y.2 RS3 enthusiasts.
NEW BOSCH ECU HARDWARE
The 8Y.2 RS3 comes equipped with the new Bosch MG1CS164 ECU. Unitronic Software Engineers quickly developed its ECU Unlock solution, which is exclusively performed in-house at Unitronic Headquarters, therefore requiring the ECUs to be sent in, in order to protect the proprietary nature of our solutions. Send-In ECU Unlocks are performed at Unitronic HQ and are typically completed SAME-DAY they are received. Depending on the shipping methods you choose at checkout, in some cases you can have your ECU back in your hands within as little as 48-hours!***. Click HERE to learn more.
With Unitronic's vast of experience with previous-gen Bosch ECUs, like found in the 8Y.1 RS3, Unitronic Engineers not only recalibrated the ECU, but also carefully reverse engineered unique and innovative proprietary ECU code, in addition to the traditional calibration based enhancements, empowering Unitronic to offer an unmatched user experience that is packed full of unique features like flex fuel and end-user adjustability, while integrating these novelties into the ECU as if they were there from the factory.
AVAILABLE STAGE 2 SOFTWARE
AVAILABLE STAGE 1 SOFTWARE
UNIFLEX (FLEX FUEL)
As part of this expansive project, Unitronic is proud to be the first to implement native flex fuel code to the factory Bosch MG1CS164 ECU called UniFLEX. Unitronic’s UniFLEX Hardware allows for a plug and play installation through its proprietary UniFLEX Module and a genuine Continental Ethanol Sensor with required fittings and harnesses.
When combined with Unitronic’s UniFLEX-enabled Performance Software Add-On, the factory Bosch MG1CS164 ECU receives ethanol content over the CAN-bus and utilizes this fuel composition data to blend mapping of timing, boost pressure, fueling, and much more completely on-the-fly. Simplified, this allows for seamless transitions from 0% to 85% ethanol content — or said another way, 100% gasoline to 85% ethanol and anywhere in between, without needing an ECU reflash.
UniFLEX is also Bluetooth® enabled, allowing for wireless connectivity with iOS and Android mobile devices using the Unitronic UniE85 Manager App. Ethanol content % and fuel temperature can also be conveniently monitored from within the virtual cockpit.
ADVANCED FEATURES (UAF)
Adding even more to the magnitude of this project, Unitronic brings its groundbreaking Advanced Features (UAF) Suite to the Bosch MG1CS164 ECU platform. Thanks to proprietary ECU code, the Unitronic Advanced Features (UAF) Software Add-On and UAF Control app gives unparalleled levels of control for true adjustability directly from your mobile phone, paired together with its FeatureBox and UAF Control App.
The Unitronic FeatureBox or UniFLEX Module act as a bridge between your vehicle and mobile device, seamlessly connecting to the factory soundaktor harness beneath the rain tray to inject a signal directly into the CAN-bus network with its included plug-n-play wiring harness. Paired with the UAF Control app, it puts advanced functionality at your fingertips in an intuitive and user-friendly interface.
Available Features
• Adjustable Standing Launch Control for boost levels and RPM set points
• Customizable Exhaust Overrun / Pops & Bangs for intensity and duration
• Rolling Launch Control (RLC) for pre-loading the engine to build boost while in motion
• Customizable Exhaust Flap Behavior adjustable by drive-mode or always open to suit your preference
• UniLOCK Immobilizer for an added layer of protection and theft deterant
• Valet Mode for added peace of mind when temporarily handing the keys to others
• iOS and Android compatibility
Unitronic has also built in plenty of failsafes and safety mechanisms into its Advanced Features to protect the engine and its components as much as possible. Unitronic has even incorporated refresh timers into its ECU code, utilizing the OEM Virtual Cockpit Torque Gauge to display 15-second countdown before RLC becomes available for reactivation, for example. Additionally, during RLC activation, the torque gauge will show a 5-second countdown during RLC activation before the function times out. Certain preconditions apply for specific functions to activate, while other criteria can also prevent them from engaging. See guide below.
Advanced Feature functionality is inhibited until the following preconditions are met, most of which are designed to maintain the utmost reliability. Required — Dynamic, Performance, or selecting S-mode from any drive mode. PNB LC RLC Each function activates only when all of its listed criteria are met, alongside the drive-mode requirement above. UAF Pre-Conditions
Drive modeExhaust Overrun
Launch Control
Rolling Launch Control
UNITRONIC MAIL-IN UNLOCK EXPLAINED: Unitronic's Mail-In Unlocks are quick and convenient with SAME DAY turnaround of your ECU with Unitronic Performance Software pre-installed! 01 / 06
UNITRONIC ECU UNLOCK (SEND-IN)
Unitronic ECU Unlocks are exclusively completed in-house at our Headquarters and are exclusively for use together with Unitronic ECU Performance Software. ECU Unlocks are typically completed SAME-DAY they are received. Depending on the shipping methods you choose at checkout, you can have your ECU back in your hands within as little as 48-hours! You can also choose to work with an Authorized Unitronic Dealer, who can handle the shipping, receiving, and reinstallation of your ECU!
MG1CS164 ECU Unlock Cost — $399.99 USD / $559.99 CAD
Available ECU Performance Software Stages:
Stage 1 — $1300
Stage 1+ — $1400
Stage 2 — $1500
Available Software Add-Ons:
UniFLEX (Flex Fuel) — +$500
Unitronic Advanced Features (UAF) — +$250
AVAILABLE HARDWARE
Unitronic offers a wide range of hardware upgrades that directly support each of its Performance Software tunes for the best possible experience. Drawing on extensive development with previous 8Y / 8V.2 RS3 and 8S TTRS 2.5TFSI EVO applications — including many record-setting and record-breaking builds — Unitronic’s high-performance hardware for the 8Y.2 RS3 is engineered to deliver maximum power and efficiency in a direct, bolt-on package.
From our super-high-flow 5” Intake System or tried-and-true 4” Carbon Fiber Intake System to our Performance Downpipe equipped with a GESi 5” G-Sport Ultra High Output UHO+ 400cpsi Catalytic Converter and even our 4" Turbo Inlet Elbow with its specific 8Y.2 RS3 PCV Adapter, each component is engineered for seamless installation and real-world performance gains. Our popular Intercooler Upgrade keeps intake air temps in-check for both factory and hybrid turbochargers while our Dogbone Mounts help improve traction and minimize drivetrain slop. (See Street Dogbone demo here)
Whether you're chasing lap times or enhancing your daily driver, Unitronic Performance Software and Hardware gives your 8Y.2 RS3 the performance edge it deserves — and we're not done yet.
4" Turbo Inlet for 8Y.2 RS3: PN: UH060-INA is required along with PN: UH063-INA (PCV Adapter)
PROVEN RESULTS
Unitronic’s 8Y.2 RS3 Software offerings were developed with an uncompromising focus on real-world performance and reliability. Before public release, our calibrations underwent extensive beta testing with trusted partners and development vehicles across the globe—on the street, track, and dyno. This global validation process allowed us to gather critical data under a wide range of driving conditions, fuel qualities, and elevations to ensure consistent, repeatable performance. The result is Performance Software that delivers exceptional power, drivability and refinement—without compromising reliability. Join the growing Facebook community of Unitronic Tuned 8Y.2 / 8Y RS3 enthusiasts HERE.
FLASH FROM HOME
This platform is fully supported with Unitronic’s UniCONNECT+ cable, empowering you to tune your vehicle from the comfort of your own home or garage after the ECU is unlocked. The cable and associated software allows you to install, and upgrade, your new Unitronic ECU tunes, in addition to reading and clearing DTCs. This is a perfect option for people who like to be autonomous or who don't have a Unitronic Authorized Dealer nearby!
APPLICATIONS
2025+ Audi RS3 2.5TFSI EVO DXH (North America)
SPECIAL NOTES
A BOSCH MG1CS164 ECU can never be reflashed back to stock once unlocked, otherwise the unlock will be overwritten.
*Subject to ECU box code availability.
**SFD filters must also be unlocked before your ECU can be reflashed or data logs can be collected via the OBD2 port with UniCONNECT+. To learn more about SFD, check out or FAQ's here: getuni.ca/sfd
***Unitronic offers easy and convenient FedEx Priority pre-paid shipping labels at the time of checkout to get your ECU shipped from you to Unitronic HQ. For best results in achieving a 48-hour turn-around, you must select FedEx Priority Express at checkout. Make sure you drop the package off at a trustworthy manned FedEx Drop Off Point. Commercial Invoice(s) must be secured in an international waybill pouch on the outside of the package, together with any label(s) provided. Failure to include all the necessary labels and/or commercial invoices could result in delays in transit. Unitronic can not be responsible for delays while in transit, with customs, or delays as a result of improper packaging on inbound or outbound shipments. Unitronic strongly recommends using a plain cardboard box that is 10"x10"x4" (25cm x 25cm x 10cm) without any other markings or labels. Boxes larger than the recommended size could incur additional costs or result in delays while in transit. Boxes with other markings or labels could result in delays, rejection, return, seizure, and/or destruction of your package. If you choose to include an AirTag or other tracking device, please ensure the tracker is secure to the ECU itself to make sure it doesn't get lost and/or not returned back to you.
Unitronic is not affiliated with any vehicle manufacturers. All Manufacturer and vehicle names and trademarks used on this web site are for identification purposes only. All trademarks and trade dress such as Audi®, RS3® and TFSI® are registered trademarks of Volkswagen® AG and Audi® AG.
*Unitronic is not affiliated with any vehicle manufacturers. All Manufacturer and vehicle names and trademarks are used in this web site are for identification purposes only. All trademarks and trade dress such as Audi ®, Volkswagen ®, VW ®, Seat ®, Skoda ®, Porsche ®, Lamborghini® GTI ®, Golf ®,Golf R ®, Golf City ®, Alltrack ®, SportWagen ®, Cupra ®, Scirocco ®, Jetta ®, GLI ®, R32 ®, Rabbit ®, Passat ®, Passat CC ®, Tiguan ®, Beetle ®, New Beetle ®, EOS ®, Touareg ®, Phaeton ® DSG ®, S Tronic ®, TSI ®, TFSI ®, VR6 ®, A1 ®, A3 ®, S3 ®, RS3 ®, Q3 ® , A4 ®, S4 ®, RS4 ®, A5 ®, S5 ®,RS5 ® Q5 ®, SQ5 ®, A6 ®, S6 ®, RS6 ®, Q7 ®, SQ7 ®, A7 ®, S7 ®,RS7 ® A8 ®, S8 ®, R8 ®, TT ®, TTS ®, TTRS ®, Boxster ®, 911 ®, 996 ®, 997 ®, 991 ®, Panamera ®, Macan ®, 918 Spyder ®, Cayenne ®, Cayman ®, Huracan ®, Huracan Performante ® are registered trademarks of Volkswagen AG, Audi AG, and Porsche AG.
