| Weistec Horsepower | 525 |
| Weistec Torque | 630 |
| Manufacturer | Weistec |
| Street legal in all the US States | No |
| Engine Family | EA839 |
| Stock Horsepower | 490 |
| See more | |
| year | make | model | trim | engine |
|---|---|---|---|---|
| 2024 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| 2023 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| 2022 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| 2021 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| 2020 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| 2019 | Audi | RS4 | Base (B9) | Twin Turbo 2.9L V6 (EA839) |
| See more | ||||
Product Description
When Audi introduced the EA839 V6 family to replace the supercharged EA837, the 2.9-liter biturbo version they built around it became the heart of the B9-generation RS4 and RS5, and it's a genuinely clever piece of engineering. Instead of hanging the turbos out on the sides of each cylinder bank, Audi tucked them into the vee between the banks, shortening the path exhaust gas has to travel and sharpening throttle response in a way you can actually feel. It's the same "hot-vee" thinking behind Audi's larger 4.0-liter V8, scaled down beautifully, and it's exactly why this engine earned a reputation as one of the sharpest-responding turbo V6s in its class. That same architecture, badged differently, even does duty in Porsche's Cayenne S and Macan GTS, which says plenty about how well Audi got this one right.
Weistec's ECU calibration for the 2.9T takes that already-excellent hardware and pushes it further. It's a software recalibration that works within the boost, fueling, and ignition strategy Audi's own engineers validated, refined with the same rigor and testing discipline as an OEM calibration rather than a generic piggyback tune. Knock protection, thermal management, and the factory's own diagnostics all stay fully intact. The payoff is real: an additional 35 horsepower and 64 lb-ft of torque waking up from hardware that already had more to give, taking an engine that was special from the factory and putting it on another level entirely.
How Do You Get Your Audi EA839 2.9T ECU Tune Tuned?
Follow these steps — this is what your specific vehicle needs and supports.
Choose Your Tune Stage
Core Improvements
Standard with this tuneFree Add Ons
Pick Your Tuning Method

Cypher Plus
Order a Cypher Plus and tune your car yourself from your phone, entirely through the MyFlasher app. Watch how it works.

Mail It In
Remove your ECU or TCU and mail it to us for tuning. Required for some applications.

In Person
Bring your vehicle, or just your ECU/TCU, to our Anaheim, CA headquarters. Call 714-202-0005 or email sales@weistec.com to schedule.

Cypher Pro Dealer
Visit a certified Cypher Pro Dealer near you. Find one with our dealer locator.
Complete The Upgrade
An ECU tune alone won't remove all factory limits or fix how power reaches the ground. Add these to round out the upgrade with no limitations.
Read the full CPC & TCU breakdown →
What is a CPC module?
The CPC (Central Powertrain Control) is a separate control unit that manages things like the active exhaust valves, radiator fan, intercooler pumps, and speed limiter. On many newer Mercedes-Benz vehicles, it also houses torque limiters that can hold back an ECU tune from reaching its full potential.
What is a TCU tune?
A TCU (transmission control unit) tune delivers faster, firmer shifts with higher line pressure, reducing clutch slip and increasing the transmission's torque capacity. It's a worthwhile upgrade on its own, or paired with an ECU tune for a fully sorted powertrain.
Good to Know
- This is a reflash of your original module, not a stand-alone unit.
- Power gains vary by vehicle, modifications, fuel, and operating conditions (ambient temperature, altitude, etc.).
- New or upgraded spark plugs are always recommended when tuning.
- Product may not be emissions compliant. Check local laws prior to installation.
- Always use a battery charger during programming.




