Audi A4 / A5 / Q5 40 TFSI ECU Tune
Real Numbers. Real Pulls.
Tap a stage — power, fuel, and required mods at a glance. Stock and Stage 1+ wheel numbers come straight off our Mainline DynoLog sheets — the chart draws Stage 1 and Stage 1+ against stock, and the full before/after session is on video below. Stage 1+ E85, Stage 2 and Stage 2+ E85 hit the rollers next.
If your tuner doesn't show before & after dyno videos, you're being lied to.
A dynamometer is a before-and-after measuring tool — not an absolute output number. What can't be faked is the delta: same car, same dyno, same 93-octane pump gas, stock vs Stage 1+ — on camera, in the video below.
How It Works — Flash From Your Phone
No shop visit. No laptop. Flash your 40 TFSI straight from your phone with the BDT flasher app and our Bluetooth OBDII dongle — then data-log and refine from the same phone.
Get Access — after purchase you're set up with the BDT flasher app and your calibration files.
Plug In — pop the BDT Bluetooth OBDII dongle into the port, pair your phone, battery healthy, key on.
Flash It Yourself — pick your stage in the app and flash it over Bluetooth in minutes. Switch stages or return to stock any time.
Data-Log From Your Phone — record live engine data right in the app and send it to BDT so we can dial your car in.
What's Included
Safety
Crackles are only fun if the car is still healthy next year. Our crackle logic is temperature-gated: when the engine runs past our heat threshold it switches the pops off by itself, then brings them back once things cool down. No guesswork, no melted parts — watch it happen.
Crackles Shut Off When It's Too Hot
Why It Matters
Overrun crackles are made by burning fuel late, after you lift. Do that on a car that is already heat-soaked and the exhaust side takes the punishment. That is why ours are not always-on: the calibration watches temperature and disables the crackle strategy automatically when it gets too hot, then re-enables it when the engine is back in its normal range.
Full sound when the car is at normal operating temperature. Automatic shut-off when it is not. You keep the pops and the engine keeps its margin.
Watch The Proof
Stock vs Stage 1+, back to back on our AWD hub dyno — 93 octane straight from the Shell pump, no additives, live data — plus a Stage 2 customer in his own words. Sound on.
Dyno Session — Stock vs Stage 1+
Less Boost. More Power.
This A4 rolled in running 25 psi from the factory. We didn't pile more on top — we pulled it back to 22–23 psi, added ignition timing and re-phased the cam timing. Result: +49 WHP and +57.5 WTQ on the same 93-octane pump gas, with the turbo working less. That's what a real calibration does.
Stock: 174.1 WHP / 202.9 WTQ
Stage 1+: 223.1 WHP / 260.4 WTQ
Boost: 25 psi factory → 22–23 psi tuned
Fuel: 93 octane, Shell pump, no additives
Customer Review — Stage 2
What Your Car Needs, Per Stage
If it is not listed as required, the tune runs without it.
| Part / Upgrade | S1 | S1+ | S1+ E85 | S2 | S2+ E85 |
|---|---|---|---|---|---|
| High-Flow Exhaust CTS B9.5 A4/A5/Q5 2.0T options: test pipe • high-flow cat • install video | — | — | — | REQ | REQ |
| Intercooler Highly recommended from Stage 1+ E85 up | REC | REC | REC | REC | REQ |
| Air Intake | REC | REC | REC | REC | REC |
| Drivetrain Inserts | — | — | REC | REC | REC |
TCU tune is not available on this platform. Final output varies with fuel quality, altitude, temperature, and vehicle health.
Maintenance
| Maintenance Item | Interval |
|---|---|
| SPARK PLUGS NGK 4905 R7438-8 Racing Plug • how-to video below | 15-20K mi |
| OIL CHANGE 5W-40 Liqui Moly • OEM FILTER ONLY • how-to video below | 5K mi |
| DSG / MANUAL TRANS FLUSH & FILTER OEM only | 30K mi |
| CENTER DIFF FLUID CHANGE quattro center differential • OEM fluid only • step-by-step video below | See video |
| MAP SENSORS OEM only • intake / before throttle body | 80K mi |
| PCV ASSEMBLY | 80K mi |
| INJECTORS + CARBON CLEANING Do them on time to avoid misfires, lean conditions, and long-term damage | 85K mi |
Do It Yourself — Step-By-Step Videos
Filmed in the BDT shop on the B9.5 2.0T platform. Every job in the table above that we get asked about, on camera. Sound on.
Center Diff Fluid Change — B9.5 quattro
Oil Change — B9.5 2.0T
Spark Plug Change — B9.5 2.0T
High-Flow Cat Install — CTS Turbo
Your ECU Is Safe
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-adopting 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 local, state, and federal laws and regulations.
- Waive all claims, liabilities, and legal actions against Boost Dynamic Tuning, LLC, its officers, directors, employees, and affiliates arising from the purchase, installation, or use of this product in violation of any applicable law.
- Release Boost Dynamic Tuning, LLC from any and all damages, injuries, or penalties resulting from improper or unlawful 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 inconsistent with this disclaimer, misrepresentation of vehicle use, or violation of any emissions laws or regulations.
Final Notice
This product is sold "as is" and "with all faults", with no warranties, expressed or implied, regarding legality for public highway use or emissions compliance. It is the sole responsibility of the end-user to determine legality 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.
HIGH-FLOW EXHAUST 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, WHETHER IN THE USA OR OTHERWISE, THE PRODUCT IS NOT DESIGNED TO BE C.A.R.B. COMPLIANT, AND THAT THE PRODUCT IS NOT FOR SALE OR USE IN CALIFORNIA, USA NOR ANY OTHER JURISDICTION WHERE THE SALE OR USE IS PROHIBITED BY LAW. BOOST DYNAMIC TUNING, LLC MAKES NO REPRESENTATIONS, WARRANTIES, OR CLAIMS THAT THIS PRODUCT COMPLIES WITH ANY APPLICABLE EMISSIONS LAWS AND EXPRESSLY DISCLAIMS ANY AND ALL SUCH REPRESENTATIONS, WARRANTIES, AND CLAIMS, WHETHER EXPRESS OR IMPLIED. BY PURCHASING THIS PRODUCT, YOU REPRESENT, WARRANT, AND AGREE THAT IT IS YOUR RESPONSIBILITY TO INFORM YOURSELF OF ANY LAWS OR REGULATIONS THAT MAY APPLY TO YOUR PURCHASE AND/OR USE OF THE PRODUCT.
Reviews
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Ecu Tune
no one else is doing it like boost dynamic tuning this tune wakes the car up its not sluggish no more i got stage 1+ and im loving it