BMW 340i tune: remap the engine and the gearbox yourself
The F30 340i is a sleeper with a B58 straight-six under the bonnet. Hellflash wakes it up: stage maps for the engine, a sharper ZF 8-speed, and the sound to match, all from your laptop.
What a Hellflash tune does to an 340i
Pick a stage, make it yours with a few plain choices, then flash it. Each stage tunes the engine, the gearbox and the pops together.
- Stage 1
- Stock hardware. About +50 to 70 hp on 98 RON, estimated.
- Stage 2
- Downpipe fitted. About +80 to 110 hp on 98 RON, estimated.
- Stage 3
- Downpipe and intercooler. The firmest shifts and the loudest pops.
- 95 or 98 RON
- Every stage is matched to the fuel you actually use.
Sound, your way
- Pops on upshift
- Off, Subtle, Nice or Loud, fired through the gearbox on a hard upshift.
- Quiet cold start
- Skips the loud catalyst warm-up, so early starts don’t wake the street.
- Exhaust flap
- Opens from a standstill for a louder note, or stays stock.
- Overrun burble
- Arrives as a free update.
Saloon, Touring or GT
The 340i saloon (F30), Touring (F31) and Gran Turismo (F34) all use the B58 with the MG1CS003 engine computer. The G20 M340i uses the B58 Gen 2: supported for tuning, with engine flashing arriving as a free update.
The gearbox, tuned too
34 ZF 8HP settings you can build and flash. The favourites:
- Shift speed
- Firmer, faster steps beyond stock.
- Shift points
- Upshift rpm for every gear in Drive, Sport and Manual.
- Ignition-cut upshifts
- The crack on a hard upshift.
- Throttle blips
- Rev-matched downshifts.
- Launch control
- Launch torque and how it blends in.
- Torque limit per gear
- Lets the box hold a tuned engine.
- Max rpm
- Raise the shift-up and rev limit.
- True manual
- Holds your gear, even at the limiter.
- Auto start-stop off
- For good.
- Valet mode
- Capped torque and gentle shifts for someone else.
How it works
- Plug in
- An ENET cable (about £15) from the OBD port to a Windows laptop, with a charger on the battery.
- Read your car
- Hellflash finds the engine and gearbox computers and saves a full backup. Free.
- Pick a tune
- A stage, a few plain choices, the full editor, or describe it to Hellflash AI.
- Flash and drive
- Checksums corrected, every write verified, back to stock any time.
Engine flashing works today on the B58 with the MG1CS003 engine computer (2016 to 2019 F-series and the early G-series 40i cars). The ZF 8HP gearbox flash is proven on a real car.
What it costs
£300 once, per car. It covers the engine and the gearbox, with updates for that car, and Hellflash AI free as it rolls out. No subscription and no credits.
Questions
Anything else, email support@hellflash.com
Is the BMW 340i supported?
Yes. The F30, F31 and F34 340i with the B58 (MG1CS003) is supported for engine and gearbox flashing.
Is the G20 M340i supported?
It is supported for tuning. Engine flashing on B58 Gen 2 cars arrives as a free update.
Will a tune make my 340i louder?
If you want it to. Pops on upshift and an earlier exhaust flap are your choice, and both can stay stock. A quiet cold start keeps early mornings calm.
Can I go back to stock?
Yes. Hellflash reads and saves your car's own software before the first flash, so you can put it back any time.
What do I need?
A standard ENET cable (OBD to Ethernet), a Windows laptop and a battery charger on the car while you flash. iPhone and Android apps are on the way.
How much does it cost?
£300, one time, per car. It covers the engine and the gearbox, with updates for that car. No subscription and no credits.
Start with a free read of your car.
Read your car for free first. If it fits, it’s £300 once and it’s yours.