Stage 1
Stage 1 · Petrol · 4.2 V8 40v Quattro 310hp
Audi A8 4.2 L Stage 1 file Bosch HW 0261203610 · 4D0907557E · SW 355809
Audi A8 4.2 L Petrol 219.9 kW (299 HP) Stage 11998, Petrol, 219.9 kW (299 hp)
310 → 435 HP +125 HP +95 Nm 40% more power
Calibrated ECU file for 0261203610 (SW 355809). Checksum-corrected, ready to flash. Delivered instantly via secure download after payment.
Performance projection
Matched engine: 4.2 V8 40v Quattro 310hp, AQF, 4.2L, Petrol. Engine #10782 in our gains database.
- Power
- 435 HP+125 HP from 310
- Torque
- 535 Nm+95 Nm from 440
- Fuel economy
- −8 %−12% full load
Real data from Gains API. Dyno curve = typical ECU-family projection. Final gains depend on fuel, altitude, wear.
How it works
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Read your ECU
With KESS, KTAG, AutoTuner or Flex. Keep the read: it is your way back.
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Match the numbers
Your read must show hardware 0261203610 and software 355809.
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Pay and download
Card, Apple Pay or Google Pay. The file is in your account straight away.
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Write it and drive
Write it back the way you read it. Not right for your car? We correct it free.
What the car needs
Required modifications: Stage 1, Petrol.
Hardware
- No hardware changes required: runs on completely stock hardware
Software / calibration
- Boost / load targets optimised within factory hardware limits
- Ignition advance refined for the running fuel grade
- Throttle response and torque request remapped
- Factory safeties (knock, lambda, EGT) preserved
Stage 1 is a software-only calibration. Compatible with stock turbo, injectors, intercooler, exhaust and clutch.
Vehicle & ECU specifications
Exact vehicle, engine and ECU identifiers this calibration file is written for. Cross-check against your ECU before flashing.
| Vehicle make | Audi |
|---|---|
| Vehicle model | A8 |
| Model year | 1998 |
| Displacement | 4.2 L |
| Fuel / Induction | Petrol |
| Factory power | 219.9 kW (299 HP) |
| ECU manufacturer | Bosch |
| ECU ID | 4D0907557E |
| ECU hardware | 0261203610 |
| ECU software | 355809 |
| Calibration stage | Stage 1 |
| OEM engine code | AQF |
| File format | BIN / ORI |
| Checksum | Pre-corrected (ready to flash) |
| Delivery | Instant download after payment |
Engine performance matrix
Power, torque and fuel-economy figures for every tuning stage on this engine, sourced from the tuning-database Gains API. Values are healthy-engine crank numbers; real on-road gains vary with fuel, altitude and mechanical condition.
| Stage | Power | Torque | Δ HP | Δ Nm |
|---|---|---|---|---|
| Original / Factory | 310 HP | 440 Nm | — | — |
| Stage 1 | 435 HP | 535 Nm | +125 (40.3%) | +95 |
| Stage 2 | 461 HP | 562 Nm | +151 (48.7%) | +122 |
| Stage 3 | 512 HP | 682 Nm | +202 (65.2%) | +242 |
| Stage 4 | 605 HP | 814 Nm | +295 (95.2%) | +374 |
About this calibration file
The Stage 1 calibration for the 1998 Audi A8 4.2L Petrol is a drop-in remap that works on completely stock hardware — no turbo, injector, intercooler or fuel-system upgrades required. Injection timing, boost targets, rail-pressure limits and torque maps are rebalanced to extract the safe headroom the OEM leaves untouched for fleet-fuel tolerance, altitude margin and warranty buffer.
This file matches a Bosch ECU with hardware number 0261203610 and software version 355809. Verify both identifiers in your flashing tool before writing — an ID mismatch is the most common cause of a bricked ECU. If you are unsure, upload a read of your original file via the file-request wizard and our engineers will confirm compatibility before you flash.
Projected output on a healthy, stock-hardware example of this engine: 435 HP and 535 Nm at the crank — a gain of +125 HP (40%) and +95 Nm over the factory 310 HP / 440 Nm baseline. These numbers are sourced from our Vehicle Performance Database, which aggregates dyno results across this engine family. Real-world gains depend on fuel grade, ambient temperature, mechanical condition and intake/exhaust state.
The file is delivered as a ready-to-flash BIN (and ORI backup where applicable) compatible with all major tools — KESS V2/V3, KTAG, AutoTuner, CMDFlash, Dimsport New Genius, MPPS, Flex, BFlash, PCMFlash, MMFlash — via OBD, bench or boot-mode as supported by your ECU family. Checksums are pre-computed and verified; no additional checksum tool is required. All files include a free revision if post-flash logs reveal a fuelling, boost or EGT issue.
Frequently asked questions
0261203610 (Bosch) listed in the specifications. Read your ECU with any supported tool (KESS, KTAG, AutoTuner, CMD, etc.) and compare the hardware + software numbers against the ones on this page. If they match exactly, the file is a direct fit. If you're not 100% sure, upload your original read via the file-request wizard and our engineers will confirm within minutes — no cost, no obligation.Product details
This product contains a calibrated Stage1 tuning file for Audi A8 4.2 L 1998 Benzin 219.9KW with Bosch 0261203610 and software ID 4D0907557E (Bosch software number 355809 ( 1037355809 )). The base stock vehicle for this calibration has a factory output of around 219.9 kW (~299 HP). This Stage 1 calibration is designed for stock hardware, offering a safe and reliable increase in power and torque for daily use.
All ECU tuning files from TUNING-DATABASE are prepared for professional use. They are useful whenever you search by ECU ID, hardware or software number such as 0261203610, 4D0907557E, 355809 (1037 + SW code). Use this file for diagnostics, cloning, recovery or as a base for custom remapping.
17861B74 2B226601 E2FD18EE F14CB7D1 7F37410D 36445A22 7FE5C1AB 41CA02B2