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Looking to remap your BMW 335d N57? This tuning guide explains safe ECU remapping, expected power gains, torque limits, emissions considerations, and supporting mods.
Primary Keywords:
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Secondary Keywords:
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🔧 Introduction: The N57 Twin-Turbo Diesel Powerhouse
The BMW 335d F30/F31 (2013–2019) is powered by the formidable N57D30T0 engine — a 3.0L inline-six twin-turbo diesel delivering strong performance out of the box and huge potential through ECU tuning.
Notable for:
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Sequential twin-turbo setup
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ZF 8HP automatic gearbox
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EDC17CP45 ECU (tuneable via OBD or bench)
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xDrive AWD platform (in most markets)
Whether you’re chasing refined daily performance, serious torque, or economy gains, the N57 remaps safely with the right approach.
📘 N57 Engine Overview – Factory Specs
| Feature | Spec |
|---|---|
| Engine Code | N57D30T0 |
| Displacement | 3.0L inline-6 |
| Power (Factory) | 313 PS (309 hp) |
| Torque (Factory) | 630 Nm |
| Turbo System | Twin-turbo sequential |
| Transmission | ZF 8HP auto |
| ECU Type | Bosch EDC17CP45 |
| Emissions Systems | DPF, EGR, AdBlue (SCR), MAF |
| Fuel Injection | Common rail (2,000+ bar) |
Stock dyno figures often show 320–330 hp, making the N57 an under-rated base for tuning.
📈 Safe ECU Tuning Stages for the 335d N57
🔹 Stage 1 Remap (Stock Hardware, Full Emissions Retained)
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✅ Safe for DPF, EGR, SCR (AdBlue), and stock drivetrain
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✅ Smooth torque delivery matched to gearbox limits
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✅ Maintains MOT and insurance compliance if declared
Expected Gains:
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+50–65 hp
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+100–130 Nm
-
Total Output: ~360–380 hp / ~730–760 Nm
Ideal For: Daily driving, towing, economy + performance blend
🔹 Stage 2 Remap (With Supporting Mods)
Required Upgrades:
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❗ Downpipe (catless or high-flow — off-road use only unless compliant)
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✅ Uprated intercooler
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✅ Optional EGR/DPF/SCR delete (if used off-road or in motorsport)
Expected Gains:
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+80–100 hp
-
+140–180 Nm
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Total Output: ~400–420 hp / ~780–820 Nm
Ideal For: Enthusiasts, track day users, or those seeking brutal torque gains
🧠 What Makes the N57 Different from the M57?
| Feature | N57 (F3X) | M57 (E9X) |
|---|---|---|
| ECU | EDC17 | EDC16 |
| Gearbox | 8HP ZF | 6HP ZF |
| Emissions | DPF + SCR + AdBlue | DPF only (later models) |
| Boost System | More advanced sequential twin-turbo | Simpler twin-turbo |
| Tuning Potential | Higher stock efficiency | Higher mod tolerance |
The ZF 8HP gearbox handles torque extremely well with appropriate torque limiter tuning.
🛠️ Pre-Tune Checks for N57 Safety
Before tuning, verify:
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✅ No fault codes (especially EGT, DPF, boost control)
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✅ Clean EGR valve and functional DPF
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✅ MAP & MAF sensor readings correct
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✅ AdBlue system intact (if retained)
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✅ Transmission adaptation values good (ZF scan)
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✅ Turbo actuator behaviour smooth
Live Data Tips:
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Boost request vs actual should match under WOT
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Fuel rail pressure > 2,000 bar under load
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EGT max temp: ~850–900°C during heavy load
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DPF pressure <15 mbar at idle = healthy
📉 Torque Management – Critical on N57
Tuning the 335d N57 requires attention to torque control layers:
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ECU software includes multiple torque limiters
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ZF 8HP has a torque capacity threshold of ~850 Nm (stock tuning range)
-
Too much low-end torque = gearbox wear or clutch pack stress
A well-built Stage 1 map delivers smooth torque progressively, preserving drivetrain integrity.
🧾 Emissions Considerations
| System | Can Be Retained? | Notes |
|---|---|---|
| DPF | ✅ Yes | Safe tuning available |
| EGR | ✅ Optional | Can be closed via software |
| SCR/AdBlue | ✅ Optional | May be retained or disabled (off-road) |
| MOT | ❗ Tampering illegal for road use | DPF and cat must be present and working |
Precision Remaps always provides emissions-legal options unless explicitly requested for off-road vehicles.
🔍 Common N57 Tuning Issues to Avoid
| Fault | Cause | Fix |
|---|---|---|
| Torque limp mode | Exceeded TCU limit | Tune gearbox map |
| EGR-related smoke | Open EGR under load | Close or recalibrate |
| DPF regen failure | Bad mapping or sensor error | Recalibrate soot triggers |
| Gearbox shudder | Over-torque in low RPM | Smooth out torque delivery |
| Overboost code | Bad actuator control | Log and revise spool curve |
WinOLS-built remaps allow for deeper correction of load and torque tables vs generic maps.
🔩 Recommended Supporting Mods
| Part | Reason |
|---|---|
| Intercooler | Cooler intake = safer EGTs, better density |
| Turbo-back exhaust | Less backpressure, faster spool (off-road use) |
| ZF8HP gearbox map | Removes torque limits, faster shifts |
| Intake upgrade | Improves throttle response (minor gains) |
| Oil catch can | Prevents intake carbon build-up |
📍 BMW 335d N57 Tuning at Precision Remaps
At Precision Remaps, we offer:
✅ Custom-built maps using WinOLS
✅ Road-tested Stage 1 and Stage 2 N57 remaps
✅ ZF 8HP torque tuning and gearbox map upgrades
✅ Diagnostics before and after remap
✅ Emissions-compliant tuning options for road users
✅ Support for AdBlue/EGR/DPF-safe setups
📍 61 Rolleston Road, Burton on Trent
🌐 https://precisionremapsuk.com
📧 car-remapping@outlook.com
✅ Quick Summary
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The N57 335d is one of the most powerful and tuneable BMW diesels ever made
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Stage 1 tuning with full emissions intact provides +50–60 hp safely
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Stage 2 adds supporting mods for 400+ hp, but requires careful calibration
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Torque management is essential to protect the gearbox and engine
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Always tune with proper diagnostics, live logging, and WinOLS-built files