Tuning · BMW 340i (F30 / F31)
340i
B58 Gen 1
The executive saloon that nobody sees coming. Hand-calibrated from Stage 1 to a fully bespoke big-turbo build. Choose your package, send your build to Samuel, and get a tune that fits the way you actually drive.
Engine
B58 Gen 1
Stock
326 bhp · 450 Nm
Stage 3 ceiling
326 bhp
About this tune
The F30 / F31 340i (2015-2019) is the executive saloon and Touring variant of the B58 Gen 1, same engine block, turbo and 8HP gearbox as the M140i and M240i, with a more conservative factory calibration (326 bhp / 450 Nm vs 335 / 500 on the M-Performance cars). The detune is purely software, which is why Stage 1 on the 340i targets the same 420 bhp / 600 Nm figure as the rest of the B58 Gen 1 family. Available as the F30 saloon and F31 Touring.
BMW 340i tuning
Nothing about a 340i warns other traffic what it is. The F30 saloon and F31 Touring look like every other 3 Series in the car park, which is exactly the appeal — a discreet executive car, or a full-sized family estate, sitting on the same engine and gearbox as the M-badged 1 and 2 Series. Owners tune the 340i precisely because the factory left so much of that potential switched off.
BMW calibrated the 340i conservatively at 326 bhp and 450 Nm, softer than the 335 bhp M-Performance cars despite identical hardware — the gap is purely software. That makes Stage 1 unusually rewarding here: the same £400 file takes a 340i to 420 bhp and 600 Nm, a jump of 94 bhp and 150 Nm with nothing changed under the bonnet. Stage 2, with downpipe and intake fitted, targets 450 bhp and 650 Nm.
For owners who keep going, the B58 Gen 1 in the 340i will support hybrid and big-turbo builds up to around 1,000 bhp, each calibrated as a one-off. There is no rolling-road booking in the process — Samuel writes the map for your specific car and delivers it to BM3, MHD or MG Flasher within a day, and because your original file is preserved, the saloon or Touring can be returned to factory software at any time.
Configurator
Build your 340i tune
Choose your stage — Stage 1, Stage 2 or Stage 3 — add the options that fit your car, and send the full build to Samuel for a custom remote remap. He'll quote, schedule, and personally calibrate within 24 hours of confirmation.
Add a stage or add-on
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Engine guide
BMW 340i tuning, stages, hardware and what to expect from the F30 B58 Gen 1
The 340i runs the B58 Gen 1 in F30 saloon and F31 Touring form, the same engine block and turbo as the M140i, M240i and 440i. BMW set the F30 340i's factory calibration at 326 bhp / 450 Nm, a more conservative software limiter than the M140i and M240i. The hardware is identical, which is why BMW 340i tuning with Samuel targets the same Stage 1 figure as the rest of the family. BMW 340i F30 tuning and BMW 340i F31 tuning use the same map; only the build sheet differs slightly for the Touring exhaust geometry.
Stage 1
420 bhp · 600 Nm
No hardware required. The MG1CS003 / MEVD17 DME is flashed via the OBD port, boost, ignition timing, fuel delivery and torque limiters all revised. BMW 340i Stage 1 unlocks 420 bhp / 600 Nm from the OEM hardware (up from 326 / 450 stock), making it one of the largest stock-hardware Stage 1 gains in the BMW range because BMW's factory limiter on the 340i is so conservative. The BMW 340i chip tuning starting point for almost every owner.
Every 340i tune Samuel produces is calibrated individually for the specific car, fuel grade and installed hardware, not a base map loaded and left. BMW 340i tuning done correctly accounts for the F30 chassis weight, the 8HP gearbox calibration and UK fuel quality; the map is reviewed against your data logs after the first flash and revised before sign-off.
Compatibility
Platform and hardware compatibility
Bootmod3 (BM3)
Full B58 Gen 1 support across the MEVD17 (early) and MG1CS003 (later) DMEs. OBD-port flashing, realtime monitoring via the BM3 app. The most widely used platform for B58 Gen 1 tuning.
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MHD
Full B58 Gen 1 support. Suitable for Stage 1, Stage 2 and Stage 2+. Strong data-logging toolset and active community support.
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MG Flasher
Full B58 Gen 1 support. Clean interface and reliable flash process. Common alternative to BM3 for owners who prefer the MG ecosystem.
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xHP Flashtool
Compatible with the ZF 8HP gearbox fitted to every B58 Gen 1 chassis. Gearbox calibration matched to the ECU map, strongly recommended once torque jumps at Stage 2 and above. Available as an add-on.
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ECU: MEVD17 DME on early production cars; MG1CS003 DME on later production. Both accessible via OBD for Stage 1, Stage 2 and Stage 2+; bench-flash only required for some Stage 3 hybrid setups.
340i specs & stage targets
BMW 340i tuning at a glance
- Engine
- B58 Gen 1
- Body styles
- F30 Saloon · F31 Touring
- Chassis codes
- F30 / F31
- Production
- 2012–2019
- Drivetrain
- Rear-wheel drive
- Gearbox
- 8-speed ZF automatic
- Stock output
- 326 bhp · 450 Nm
- Tuning ceiling
- ~1000 bhp on the right hardware
| Stage | Target |
|---|---|
| Stage 1 | 420 bhp · 600 Nm |
| Stage 2 | 450 bhp · 650 Nm |
| Stage 2+ | 480 bhp · 680 Nm |
| Stage 3, Hybrid Turbo | 550-1000 bhp depending on spec |
| Stage 3, Big Turbo Kit | 550-1000 bhp depending on spec |
FAQ
340i tuning — frequently asked questions
Market positioning. The B58 Gen 1 in the 340i is the same block, turbo and fuel system as the M-Performance cars; BMW simply mapped it to 326 bhp and 450 Nm instead of 335 and 500. Because the difference is calibration rather than hardware, a Stage 1 340i reaches exactly the same 420 bhp and 600 Nm as its siblings.
The largest in the B58 Gen 1 range — 94 bhp and 150 Nm over stock, taking the car from 326 bhp and 450 Nm to 420 bhp and 600 Nm with no hardware required. The conservative factory map means the 340i has further to travel than the M-badged cars, so the transformation feels bigger from the driver's seat.
No — the estate carries the identical drivetrain, so all stages and figures apply to both bodies. What does differ is each individual car: fuel grade, mileage, fitted hardware. Samuel calibrates every 340i file against those specifics, which is why a Touring used for family duties and a stripped-out saloon don't receive the same map.
Yes, and it is built into the file. Samuel asks what you actually run before calibrating, because higher-octane super unleaded allows more ignition advance and more consistent power than standard 95 RON. If you switch fuels later, say so — the map should always match what goes in the tank rather than assume a best case.
The engine can, with the right supporting build. Getting there means a full-frame turbo, an uprated fuel pump, port injection on high-output setups and a calibration developed around that exact combination — outputs land between 550 and 1,000 bhp depending on spec. Send Samuel the complete parts list and the file is built bespoke to it.
Keep exploring
Keep exploring 340i tuning
Other B58 Gen 1 models we tune: M140i, M240i, 440i.
Engine guide
B58 Gen 1 tuning
Every B58 Gen 1 BMW we calibrate, with the full Stage 1, 2 and 3 breakdown for the engine.
Learn moreStages
Stage 1 & Stage 2 explained
What separates Stage 1 from Stage 2 on the 340i, the real-world gains and the hardware each one needs.
Learn morePricing
How tuning is priced
How the licence, off-the-shelf maps and custom calibration are priced. We quote your exact spec, never a fixed menu.
Learn moreGuide
What is bootmod3?
New to remote flashing? A plain-English explainer on the platform and how a custom map reaches your car.
Learn more