Audi RS4 4.2 FSI V8 420hp Remap

The Audi RS4 4.2 FSI V8 420hp is a 4.2L naturally aspirated petrol engine producing 420 BHP and 430 Nm from the factory. With a typical Stage 1 remap, output increases to approximately 440 BHP and 455 Nm — a gain of around 20 BHP (5%) and 25 Nm (6%).

This engine has limited remap suitability, though the available headroom is limited, so gains are modest compared to higher-output variants. The tuning headroom is classified as limited, based on the percentage gain available from the factory output.

From a technical perspective, the ECU is typically a Bosch MED9/MED17 (varies), and the transmission is manual and dsg/s tronic automatics are common depending on model/engine. some dsg/dual-clutch gearboxes have torque management; calibration may be torque-limited. at this torque level, transmission and driveline servicing history becomes especially important..

Considerations: Naturally aspirated engine: gains are usually limited; results vary widely.. High tuned torque: check transmission torque capacity and service history.

All figures shown are typical estimates based on aggregated Stage 1 data for this engine variant. Actual results depend on vehicle condition, mileage, and the chosen tuning method. We recommend discussing your specific vehicle with a qualified remap professional.