2021 - 2025 MILD HYBRID Audi 45 TFSI B9.5 A5 A4 2.0t Stage 2 (Remote Tune)
2021–2025 Audi A4 / A5 45 TFSI Stage 2 ECU Tune (B9.5 Hybrid EA888)
Boost Dynamic Tuning • OBDII Remote Flash
Exclusive USA-Based Calibration for the B9.5 Hybrid 2.0T Platform
If you own a 2021–2025 Audi A4 or A5 45 TFSI (B9.5 Hybrid EA888 Gen 3 2.0T), you’re holding untapped power — and we’re the only USA-based tuner with a proven solution to unlock it safely. Our Stage 2 ECU calibration is designed specifically for this hybrid platform, and no one else in the country offers what we do.
With 11+ years of in-house calibration experience, every file is built from scratch and validated through real-world logging and before/after dyno testing — no theoretical numbers, no resold maps, no gimmicks. Just repeatable power with OEM+ drivability.
Why Choose BDT?
- Exclusivity: The only USA-based Stage 2 solution proven on the B9.5 hybrid platform.
- Authenticity: 100% in-house development — no resellers, no copy/paste maps.
- Transparency: Dyno-backed results and real-world testing.
- Remote Convenience: Flash from home via OBDII — no shop visit required.
This isn’t just tuning — it’s engineering with passion, built for drivers who demand more from their Audi.
Fitment & Compatibility
- Models: Audi A4 45 TFSI / Audi A5 45 TFSI
- Years: 2021, 2022, 2023, 2024, 2025
- Chassis: B9.5
- Engine: Hybrid EA888 Gen 3 2.0T
- Fuel: 91 or 93 Octane Pump Gas
- Tuning Method: Remote OBDII Flash (At-Home)
- Hardware Required: High Flow Cat/ High flow exhaust
Stage 2 Power Gains (Pump Gas)
Unleash up to 320 WHP / 368 WTQ on pump gas with refined boost targeting, torque management, and stronger mid-range pull. Stage 2 is calibrated for cars running the recommended supporting hardware (intake/intercooler).
| STAGE | HORSEPOWER | TORQUE |
| Stock 45 TFSI (Audi Advertised) | 261 HP | 273 TQ |
| Stock 45 TFSI (BDT Dyno) | 255 WHP | 255 WTQ |
| BDT Stage 2 45 TFSI | 320 WHP / 368 HP | 346 WTQ / 397.9 TQ |
BDT Stage 2 Highlights
- Optimized boost and torque delivery for smoother, harder pulls
- Intake Air Temp Safety alert (dash warning when pushing too hard)
- Speed limiter removed
- Torque limiters raised
- Raised rev limiter (Neutral/Park)
- Load limits raised
- Auto Start/Stop defaults OFF (still functional)
- Crackle/Overrun in Dynamic mode only
- Calibrated stock boost gauge for higher readings
- Sharper throttle response & reduced turbo lag
- Increased LPFP & HPFP pressure
- VVT recalibration
- Flashable via OBDII — no shop visit required
ECU Tune Modification Requirements
| PART / UPGRADE | REQUIRED | RECOMMENDED |
| TCU Tune | — | Not Available |
| Air Intake | — | X |
| Intercooler | — | Highly Recommended |
| Drivetrain Inserts | — | X |
| High Flow Exhaust | X |
Remote Flash from Home (OBDII)
No shop visit. No downtime. Flash your ECU at home through the OBDII port — and BDT provides guided remote support every step of the way.
Remote Tuning How-To
Built for the Streets. Proven on the Dyno.
Whether you're carving through backroads or making a statement at your next meet, Stage 2 gives your Audi the edge — with the refinement you expect from a luxury performance build.
Stop leaving power on the table. Elevate your driving experience with BDT’s Stage 2 calibration for the 2021–2025 Audi A4/A5 45 TFSI B9.5 Hybrid.
Dyno Session Live
Stage 2 vs JB4 Stage 2
Crackle Pops / Overrun (Dynamic Mode Only)
Bring your Audi to life with our overrun/crackle calibration — a crowd-favorite feature that adds drama and personality to every drive.
When decelerating from higher RPMs or free-revving in Neutral/Park, you’ll hear sharp, exhilarating pops and crackles. It’s a controlled and safe enhancement designed to deliver an aggressive sound profile that turns heads — especially when paired with an aftermarket exhaust.
Note: Effect may be more subtle on stock exhaust systems. Safety logic reduces crackles if exhaust temperatures rise excessively.
⚡ Boost Control Optimization
From the factory, the stock ECU delivers a rough and inconsistent boost curve — often resulting in delayed throttle response and a lack of urgency under high load.
With BDT’s Stage 2 ECU Calibration, we completely refine the boost control strategy to deliver:
- Smoother, more linear boost delivery
- Sharper throttle response
- Consistent power across the entire powerband
The result is immediate, predictable power that keeps you planted and fully engaged.
Customer Reviews + Live Phone Chat
Maintenance Schedule (Required for Tuned Vehicles)
IF YOU WANT YOUR CAR TO SURVIVE, THESE MUST BE DONE!
I want your car to survive multiple years with my tune. This isn’t a “nice to have” list — it’s what I’ve seen work over years of tuning MQB/EA888 cars. If you can’t afford the maintenance, please don’t tune the car. This is how you keep it reliable.
| MAINTENANCE ITEM | MILES |
| SPARK PLUGS NGK R7438-8 Racing Plug |
Every 15–20K |
| OIL CHANGE 5W-40 Liqui Moly Oil Filter = OEM Only |
Every 5K |
| DSG / MANUAL TRANSMISSION FLUSH & FILTER OEM Only |
30K |
| MAP SENSORS (OEM Only) Intake / Before Throttle Body |
50K |
| PCV ASSEMBLY | 50K |
| INJECTORS + CARBON CLEANING | 65K |
EMISSIONS COMPLIANCE NOTICE & LEGAL DISCLAIMER
FOR COMPETITION USE ONLY — NOT FOR STREET USE
This product is sold and intended solely for vehicles used in closed-course racing, off-road competition, or organized motorsport events. It is not legal for use on any pollution-controlled vehicle operated on public roads or highways, as defined under the Clean Air Act (42 U.S.C. § 7522) and applicable state emissions laws.
By purchasing, installing, or using this product, you explicitly acknowledge and agree to the following terms:
Federal and State Emissions Compliance
- This product may modify, bypass, defeat, or render inoperative one or more emissions control devices, including but not limited to: catalytic converters, oxygen sensors, EGR systems, or OBD monitoring systems.
- The installation or use of this product on any vehicle subject to emissions regulations is strictly prohibited by federal law and may result in civil or criminal penalties, including fines up to $45,000 per vehicle under the Clean Air Act.
- This product is not certified by the EPA or CARB, and is therefore not legal for sale or use in California or any CARB-aligned state.
Assumption of Risk and Waiver of Liability
By purchasing and/or installing this product, you agree to:
- Assume all risk and responsibility for compliance with applicable emissions laws.
- Waive all claims, liabilities, and legal actions against Boost Dynamic Tuning, LLC and affiliates arising from unlawful use.
- Release Boost Dynamic Tuning, LLC from any damages or penalties resulting from improper or illegal use.
⚖️ Indemnification Clause
You further agree to indemnify, defend, and hold harmless Boost Dynamic Tuning, LLC from any fines, penalties, damages, losses, or legal fees resulting from:
- Use of this product in a manner inconsistent with this disclaimer
- Misrepresentation of vehicle use
- Violation of emissions laws or regulations
Final Notice
This product is sold “as is” and “with all faults”, with no warranties regarding legality for highway use or emissions compliance.
It is the sole responsibility of the end-user to determine the legality of this product for the intended application. Boost Dynamic Tuning, LLC does not condone or recommend illegal street use or emissions equipment tampering.
By completing your purchase, you acknowledge that you have read, understood, and agreed to this disclaimer in full.
DOWNPIPE NOTICE: BY PURCHASING A MOTORSPORT/RACING PRODUCT ("PRODUCT"), YOU REPRESENT THAT YOU UNDERSTAND AND AGREE THAT: THE PRODUCT IS NOT DESIGNED TO MEET ANY APPLICABLE EMISSIONS STANDARDS, THE PRODUCT IS NOT C.A.R.B. COMPLIANT, AND IS NOT FOR SALE OR USE IN CALIFORNIA OR ANY JURISDICTION WHERE PROHIBITED BY LAW. BOOST DYNAMIC TUNING, LLC DISCLAIMS ANY CLAIMS OF EMISSIONS COMPLIANCE. BY PURCHASING, YOU AGREE IT IS YOUR RESPONSIBILITY TO INFORM YOURSELF OF ALL APPLICABLE LAWS.