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APR ECU Upgrade - 2.5T EA855 (PQ35 RS3/TTRS)
Fits 2011-2014 Audi TT RS
APR ECU Upgrade - 2.5T EA855 (PQ35 RS3/TTRS)
Fits 2011-2014 Audi TT RS
Features:
- Horsepower - More horsepower throughout the whole rpm band
- Torque - More torque throughout the whole rpm band
- Program Switching - Change programs and access features with your cruise control stalk
- APR Mobile - Change programs and access features with your smart device
- Valet Mode - Neuters the vehicle, giving the driver minimal output
- Anti-Theft - Password protects driving the vehicle
- Security Lockout - Password protects program switching
- Fault Code Erase - Resets ECU fault codes and adaption on the fly
- Fuel Grades - Multiple octanes from which to choose
- Acceleration - Accelerate faster with more power and reduced throttle lag
- Brake Boosting - Left foot braking or brake boosting added
- Rev Limiter - Increased redline for higher revving
- Motorsport Limiter - With the soft limiter removed, you’ll get full power right up to the hard, “bap bap bap” redline fuel cut
- Speed Limiter - Go as fast as you want with the speed limiter out of the way
- Economy - While cruising, or driving normally, your fuel economy may benefit from our optimized calibration
- Flash Counter - Flash counter does not increase with each flash
- APR CCD Programming - The first flash is through the ECU board with the APR CCD
- Free Updates - Get free updates for life
- Guarantee - 30 day money back guarantee
Brand | APR |
---|---|
Engine Aspiration | Turbocharged |
Engine Configuration | I5 |
Engine Displacement | 2.5L |
Engine Family | EA855 GDI |
Engine Orientation | Transverse |
Fuel Type | Gasoline |
Market | NAR |
ROW | |
Product Type | ECU Upgrade |
Part Number | ECU-25T-EA855-PQ35 |
Important fuel quality information
Find your boxcode and revision
Program switching guide
Have a question about this product?
APR ECU Upgrade Stages
APR’s ECU Upgrades are available in multiple octanes levels. Each stage is fully compatible with an upgraded intake, catback exhaust, or other minor bolt on modifications.
APR Stage 1
The APR Stage 1 ECU Upgrade is the first step towards making more power! This simple upgrade requires no engine hardware modifications and produces 409-442 HP with 438-482 FT-LBS of torque. To get more power, the vehicle can be outfitted with an upgraded intake, intercooler, catback exhaust, and various other bolt-on modifications all without requiring any new modifications to the ECU.
APR Stage 1 is available for 91 AKI, 93 AKI, and 100 AKI in North America, and 95 RON, 98 RON, and 104 AKI in the Rest of the World.
APR Stage 2
The APR Stage 2 ECU Upgrade is the next step towards making more power! This simple upgrade requires an exhaust system and no other engine hardware modifications and produces 419-453 HP with 441-485 FT-LBS of torque. To get more power, the vehicle can be outfitted with an upgraded intake, intercooler, and various other bolt-on modifications all without requiring any new modifications to the ECU.
APR Stage 2 is available for 91 AKI, 93 AKI, and 100 AKI in North America, and 95 RON, 98 RON, and 104 AKI in the Rest of the World.
Horsepower and Torque Dyno Charts
Select a Dyno | Select a Dyno Type |
---|---|

APR Calibration Report
Stage | HP | TQ | Max Gain | Max Gain |
---|---|---|---|---|
Stock As Reported by VAG | 338-360 PS | 332-343 FT-LBS | ||
Stock As Measured by APR | 374 HP | 361 FT-LBS | ||
Stage 1 | ||||
91 AKI / 95 RON | 409 HP | 438 FT-LBS | +72 HP | +89 FT-LBS |
93 AKI / 98 RON | 410 HP | 447 FT-LBS | +76 HP | +95 FT-LBS |
100 AKI / 104 RON | 442 HP | 482 FT-LBS | +109 HP | +132 FT-LBS |
Stage 2 | ||||
91 AKI / 95 RON | 419 HP | 441 FT-LBS | +80 HP | +91 FT-LBS |
93 AKI / 98 RON | 431 HP | 476 FT-LBS | +96 HP | +123 FT-LBS |
100 AKI / 104 RON | 453 HP | 485 FT-LBS | +112 HP | +135 FT-LBS |
Only use fuel equal to or higher than specified. Never use a lower octane fuel. Always follow our fuel guide, especially with race fuel and Ethanol, where available. Dynos are for reference only. Results will vary. Contributing factors include the vehicle condition, vehicle setup, dyno type, dyno setup, environmental factors, fuel quality, and more. When describing fuels, the North American Region (NAR) uses the Anti-Knock Index (AKI), (RON+MON)/2, or (R+M)/2. The Rest of the World (ROW) uses RON. RON is Research Octane Number and MON is Motor Octane Number.
Program switching allows you to access additional program modes and features from your cruise control stalk or your smart device with APR Mobile. Depending on the ECU, available memory, and selected options, up to four program modes and all features, can be installed.
- Stock Mode - Go back to the stock power levels.
- Performance Modes - Switch between octanes and program modes.
- Valet Mode - Neuters the vehicle, giving the driver minimal output.
- Security Lockout - Password protects program switching.
- Anti-Theft - Password protects driving the vehicle.
- Fault Code Erase - Resets ECU fault codes and adaptation.
APR Mobile
APR Mobile installs on smartphones, tables and other devices, and connects wirelessly to your ECU. The app can then be used to access features such as program switching, fault code reading and resetting, and high speed data logging.
The APR Difference

Who we are - We’re a global automotive engineering firm nestled in Opelika, Alabama. Our 80,000ft² state-of-the-art facility is home to some of the best engineers in the industry, who have mastered hundreds of engine management systems. We have multiple engine and chassis dynos, and the resources necessary to create our ECU Upgrades in-house, from the ground up! We're not a new company either. We've been around since the 90's and we have a strong financial backing to ensure we'll be here to support you for decades to come!
What we do - We optimize everything to make your engine more powerful. We adjust air-fuel ratios, advance ignition, increase boost pressure, alter cam positions and lift profiles, and more, all depending on the type of engine and management system, of course! We don’t take shortcuts, and we don’t take risks. We do it the right way.
How we differ - With our proprietary calibration and direct ram access data logging tools and operating system code changes, we’re able to make some of the strongest and fastest ECU upgrades, without needing costly end user adjustments. We work with the ECUs intelligent modeling and closed-loop systems, and beta test in multiple environments to create upgrades that work no matter where you drive!
APR Software Pricing Guide
Our performance software upgrade is available in multiple stages with optional features.
APR Stage 1 | |
---|---|
APR Stage 1 ECU Upgrade | $599.95 |
APR Stage 2 - Not for sale in the USA | |
APR Stage 2 ECU Upgrade | $749.95 |
APR Stage 2 ECU Upgrade from Stage 1 | $149.95 |
Optional Features | |
Program Switching | $99.95 |
Purchasing, Guarantee, and Updates
How to Purchase - APR Software Upgrades are only available through Authorized APR Dealers. The dealer will connect to your vehicle, and install the update.¹
Money-Back Guarantee - Try our Software Upgrades for up to 30 days, risk free! If you are not satisfied, return to an APR Dealer to have it removed and refunded.²
Free Updates - If we make an update, add a standard feature, or if the manufacturer issues an update, you are entitled to a free update.³
1. APR Software may not be available for all vehicles. Stages, programs, and features may not be available for all ECUs.
2. Excludes some Software Upgrades, such as those included with a hardware purchase. Labor charges are at the discretion of the installer.
3. Subject to availability. Labor charges are at the discretion of the installer. Applicable to the original purchaser. Second hand owners may inquire with an APR Dealer about a software license transfer fee.
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*Free Shipping & Handling only offered to the contiguous US on orders over $100, excludes clearance parts and oversized packages.
Some parts are not legal for use in California or other states with similar regulations.