2021–2025 Audi A4 / A5 45 TFSI Stage 2+ E85 ECU Tune (B9.5 Hybrid EA888)
Boost Dynamic Tuning • Full E85 Calibration • OBDII Remote Flash

Exclusive USA-Based Stage 2+ E85 Solution 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 sitting on huge untapped potential — and we’re the only USA-based tuner with a proven path to unlock it on ethanol. At Boost Dynamic Tuning, we don’t follow the crowd — we lead it. Our Stage 2+ E85 ECU calibration is engineered 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 developed from scratch and validated through real-world logging and dyno testing — no theoretical numbers, no resold maps, no gimmicks. You get repeatable power with clean OEM+ drivability.

Why Choose BDT?

• Exclusivity: The only USA-based Stage 2+ E85 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: Full E85 ONLY (no pump-gas blending)
• Tuning Method: Remote OBDII Flash (At-Home)
• Hardware Required: High Flow Cat, and Front Mount Intercooler.

Stage 2+ E85 Power Gains

Ethanol changes everything — cooler charge temps, higher octane, and more knock resistance. Our Stage 2+ E85 file is designed to take full advantage of that headroom for stronger midrange and top-end pull.

Unleash up to 350 WHP / 390 WTQ with Stage 2+ E85.

BDT Stage 2+ E85 Highlights

• Full E85 calibration with refined ethanol torque and boost strategy
• 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 control for ethanol fueling
• VVT recalibration
• Flashable via OBDII — no physical ECU mods required

Stage 2+ E85 Hardware Requirements

Fuel Note: This file is calibrated for full E85 only. Do not mix pump gas. Always verify ethanol content from a quality station. If your local E85 quality is inconsistent, message us before flashing.

Remote Flash from Home (OBDII)

No shop visit. No downtime. Flash your ECU at home through the OBDII port — 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 showing out at the next meet, Stage 2+ E85 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+ E85 calibration for the 2021–2025 Audi A4/A5 45 TFSI B9.5 Hybrid.

Dyno Session Live

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 EA888 cars. If you can’t afford the maintenance, please don’t tune the car. This is how you keep it reliable.

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:

1. Assume all risk and responsibility for compliance with applicable emissions laws.
2. Waive all claims, liabilities, and legal actions against Boost Dynamic Tuning, LLC and affiliates arising from unlawful use.
3. 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.

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