340i — Stage 2 ECU & TCU Tune
- 26% power increase to 213kW
- 25% torque increase to 422Nm
- Reduced intake temperatures below 40°C
- Optimized charge cooler control
- Improved transmission line pressure
- Enhanced shift quality and response
The B58 in this RWD 340i responds well to the usual Stage 2 combination: intake, downpipe, and charge cooler control, paired with a matched ECU and TCU remap on the factory platform. The result is 213 kW at the wheels, up from 169 kW, with torque lifting from 338 Nm to 422 Nm.
The transmission remap is doing more work here than most people expect. It's holding gears longer under load, firming shifts where it counts, and keeping the B58 in the meat of the torque curve during harder driving. On 98 RON the calibration stays safe for daily use while still making the car feel properly quick.
This setup balances driveability with the kind of bump you actually notice on the road. The factory ECU handles it without fuss, and the supporting mods are straightforward enough for most workshops to spec and fit.
What does the TCU tune actually change on the 340i?
It firms shift pressure, raises torque limiters to match the ECU tune, adjusts shift points, and tweaks lock-up behaviour. The gearbox holds gears longer under throttle and responds more predictably during spirited driving.
Is 98 RON enough for this Stage 2 setup?
Yes. The calibration is built around 98 RON, which is widely available and suits daily driving. The power and torque figures reflect what's safe and repeatable on that fuel grade.
Does the B58 need a tune to support the downpipe and intake?
Absolutely. Without a remap, the factory ECU will pull timing and limit boost when it sees the changed airflow and reduced backpressure. The tune brings everything back into balance.
This calibration was developed for a workshop like yours
The BMW 340i above was calibrated by Protunes for a partner workshop — they did the vehicle work and kept their customer; we did the calibration engineering on the Factory. Add professional ECU and TCU calibration to your workshop without employing a calibration engineer.
Apply for Workshop Access