Stage 2
Stage 2 · Petrol · 320si 173hp
BMW E30 325i Stage 2 file Bosch HW 0261200173 · SW 355705
BMW E30 325i Petrol 125.8 kW (171 HP) Stage 2Petrol, 125.8 kW (171 hp)
173 → 196 HP +23 HP +31 Nm 13% more power
Calibrated ECU file for 0261200173 (SW 355705). Checksum-corrected, ready to flash. Delivered instantly via secure download after payment.
Performance projection
Matched engine: 320si 173hp, N45B20A, 2L, Petrol. Engine #852 in our gains database.
- Power
- 196 HP+23 HP from 173
- Torque
- 231 Nm+31 Nm from 200
- 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
-
Read your ECU
With KESS, KTAG, AutoTuner or Flex. Keep the read: it is your way back.
-
Match the numbers
Your read must show hardware 0261200173 and software 355705.
-
Pay and download
Card, Apple Pay or Google Pay. The file is in your account straight away.
-
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 2, Petrol.
Hardware
- Sport / decat downpipe (or sports-cat)
- High-flow air intake
- Optional: front-mount intercooler upgrade for sustained boost
Software / calibration
- Cat-warm-up & secondary lambda re-mapped for decat hardware
- Boost target raised in line with cooling capacity
- Knock / ignition advance re-trimmed
- Idle and load-transition tables refined
Stage 2 keeps the factory turbo and internals. Final figures vary slightly with the exact hardware fitted.
Vehicle & ECU specifications
Exact vehicle, engine and ECU identifiers this calibration file is written for. Cross-check against your ECU before flashing.
| Vehicle make | BMW |
|---|---|
| Vehicle model | E30 325i |
| Fuel / Induction | Petrol |
| Factory power | 125.8 kW (171 HP) |
| ECU manufacturer | Bosch |
| ECU hardware | 0261200173 |
| ECU software | 355705 |
| Calibration stage | Stage 2 |
| OEM engine code | N45B20A |
| 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 | 173 HP | 200 Nm | — | — |
| Stage 1 | 185 HP | 220 Nm | +12 (6.9%) | +20 |
| Stage 2 | 196 HP | 231 Nm | +23 (13.3%) | +31 |
| Stage 3 | 285 HP | 310 Nm | +112 (64.7%) | +110 |
| Stage 4 | 337 HP | 370 Nm | +164 (94.8%) | +170 |
About this calibration file
The Stage 2 calibration for the BMW E30 325i Petrol is written for vehicles with supporting bolt-ons: a higher-flow downpipe or sports catalyst, upgraded intercooler and upgraded intake are recommended. Boost targets, fuel-rail pressure, injector duration and VGT positioning are pushed further than a Stage 1 map while keeping exhaust-gas temperatures inside safe bands.
This file matches a Bosch ECU with hardware number 0261200173 and software version 355705. 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: 196 HP and 231 Nm at the crank — a gain of +23 HP (13%) and +31 Nm over the factory 173 HP / 200 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
0261200173 (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 Stage2 tuning file for BMW E30 325i Benzin 125.8KW with Bosch 0261200173 (Bosch software number 355705 ( 1037355705 )). The base stock vehicle for this calibration has a factory output of around 125.8 kW (~171 HP). Stage 2 is intended for cars with supporting modifications (exhaust, intake, intercooler) and delivers a stronger performance gain.
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 0261200173, 355705 (1037 + SW code). Use this file for diagnostics, cloning, recovery or as a base for custom remapping.
01F8186B 5940D88F BB5FB793 47436B26 48615571 4755B545 A9512F6E 9971BA4D