Cars / Vans · ECU Remapping
BMW M3 4.0i V8 420 hp Tuning (2006–)
Factory specification and Stage 1 remap gains for the BMW M3 4.0i V8 420 hp (2006–). A Stage 1 calibration adds 26 BHP and 30 Nm — software only, no hardware modifications required.
| Measure | Stock | Stage 1 | Stage 2 | E85+ |
|---|---|---|---|---|
Power BHP | 420 | 446 +26 BHP · +6% | 468 +48 BHP · +11% | 446 +26 BHP · +6% |
Torque Nm | 400 | 430 +30 Nm · +8% | 452 +52 Nm · +13% | 430 +30 Nm · +8% |
+26 BHP
Stage 1 power gain
+30 Nm
Stage 1 torque gain
Rolling road
Dyno Graph
Power (BHP, solid) and torque (Nm, dashed) across engine speed (RPM). Peak figures match our database exactly.
Hover / touch the graph
Stock: 420 bhp · 400 Nm (peak)
Stage 1: 446 bhp · 430 Nm (peak)
Stage 2: 468 bhp · 452 Nm (peak)
Tuning tool compatibility
This ECU is listed in 2 of 4 manufacturer compatibility databases.
AutoTuner
Supported
ECU: Continental MSS60
Alientech KESS3
Not listed in this manufacturer's data — ask us, coverage updates frequently.
Magicmotorsport FLEX
Not listed in this manufacturer's data — ask us, coverage updates frequently.
Dimsport New Genius / New Trasdata
Supported
ECU: Siemens/Continental MSS60
Existing customers upload their ECU file via the Regal Tuning File Portal. New to Regal? Request a quote first.
About this remap
BMW M3 4.0i V8 420 hp Stage 1 — what changes
The BMW M3 4.0i V8 420 hp (2006–) leaves the factory at 420 BHP and 400 Nm of torque. Manufacturers deliberately detune this engine to separate it from more expensive variants in the range — a Regal Tuning Stage 1 calibration safely recovers that headroom through the ECU alone: no hardware changes, no dyno risk, fully reversible.
Fuelling, boost pressure, ignition and torque limiters are optimised within the safe tolerances of the 4.0i V8 420 hp powertrain (petrol). The result is 446 BHP and 430 Nm with factory smoothness, cold-start protection and emissions behaviour retained.
Why Regal Tuning
Verified on the dyno, backed by 20+ years
Every calibration is developed and verified by Regal Tuning on an in-house 4WD dynamometer and proven across a worldwide dealer network. Your file is supplied through the Regal Tuning file portal with full technical support, and the original factory file is always kept so the vehicle can be returned to stock at any time.
Figures shown are for this exact engine variant. Gains depend on vehicle health, fuel quality and conditions — we confirm the expected output for your specific vehicle in writing before work begins.
BMW M3 4.0i V8 420 hp remap FAQ
How much power does Stage 1 add?
Stage 1 takes the 4.0i V8 420 hp to 446 BHP and 430 Nm — a gain of 26 BHP and 30 Nm over stock.
Is Stage 1 safe for this engine?
Yes — software-only calibration within the safe mechanical tolerances of the engine, gearbox and drivetrain, developed and verified on our in-house 4WD dyno.
How do I get this remap?
Request a quote with your vehicle details or registration. Existing customers upload their ECU file through the Regal Tuning file portal for a fast turnaround.
20+ years of ECU calibration
Ready to unlock your BMW M3's real performance?
Tell us your vehicle and registration — we'll confirm support and the exact expected gains for your engine before any work begins.