B58 Gen 1 · 3.0 single-turbo inline-six

BMW B58 Gen 1 tuning

The B58 is a 3.0-litre inline-six built around a closed-deck block and a single twin-scroll turbo. The closed-deck structure handles cylinder pressure better than the open-deck N55 it replaced. The turbo has headroom BMW leaves unused. The factory calibration is set to pass emissions testing across every market the car sells in, not to hit the engine's limit. A custom remap adjusts both the boost and the fuelling to actually use what the architecture offers.

See the B58 Gen 1 chassis

B58 Gen 1 vehicles

BMW B58 Gen 1 tuning, by model

SamuelTuned covers B58 Gen 1 tuning and remapping across the BMW M140i (F20 / F21), BMW M240i (F22 / F23), BMW 340i (F30 / F31) and BMW 440i (F32 / F33 / F36). Each one gets a custom, individually-calibrated remote ECU remap — Stage 1, Stage 2 and Stage 3. Open the configurator on your car to choose your stage, add the options that fit, and send the full build to Samuel.

F20 / F21

M140i

335 bhp stock

M140i Configure Tuning

F22 / F23

M240i

335 bhp stock

M240i Configure Tuning

F30 / F31

340i

326 bhp stock

340i Configure Tuning

F32 / F33 / F36

440i

326 bhp stock

440i Configure Tuning

Engine guide

BMW B58 Gen 1 tuning explained

The B58 Gen 1 engine

BMW introduced the B58 in 2015 to replace the N55. The headline change was the block. The N55 had an open-deck design, where the cylinder bores are not enclosed at the top of the block. The B58 came with a closed-deck block, which closes that structure and handles higher cylinder pressure without deforming. That is the foundation the power figures sit on. It landed first in the M140i and M240i, then in the 340i and 440i. All of them come from the factory with a clear gap between what the engine runs and what it can hold.

Why custom calibration

These cars have been around since 2015. Mileage, fuel quality and any modifications all affect how the engine responds to a map. A generic off-the-shelf file applies the same boost and timing to every car regardless. Samuel works from your datalogs, setting the calibration to your specific car, your fuel and your condition. That is how you get the full gain safely, and it matters more as the build goes further, especially on E85 where the fuel reading and the timing window have to be right.

Stages and hardware

Stage 1 needs no hardware at all. It is a software-only remap on the stock turbo. Stage 2 brings in a downpipe, with an OPF delete on cars fitted with a particulate filter, and an intake. E85 flex is the highest-value step on stock internals: a flex-fuel kit and an ethanol map push the build well past what pump fuel allows. The stock turbo will cap the build eventually. A hybrid turbo opens up 500+ bhp territory with the right fuel and a bespoke calibration built for the specific setup.

Tune stages

B58 Gen 1 tuning stages: Stage 1, Stage 2 & Stage 3

Stage 1

~400–430 bhp

Software only on the stock turbo. Transforms the car.

Stage 2

~460–490 bhp

Downpipe + intake. Bigger, sustained delivery.

E85 flex

500+ bhp

Flex-fuel kit + ethanol map, the best value gain on the B58.

Hybrid turbo

Quoted per build

Upgraded turbo + supporting fuel. Bespoke calibration.

Figures are indicative and depend on the exact model, fuel and supporting hardware. Every tune is calibrated individually — open the configurator for your car for the precise build and price.

FAQ

B58 Gen 1 tuning, common questions

A custom Stage 1 on the B58 Gen 1 on quality pump fuel typically lands around 400–430 bhp. That is 65–95 bhp over the standard M140i or M240i with no hardware at all. Stage 2 with a downpipe sits around 460–490 bhp. E85 takes the build beyond 500 bhp. Open the configurator for your car for the specific build and price.

No. Stage 1 is software only on stock hardware. No downpipe, no intake, nothing to source or fit before you flash. Hardware comes in at Stage 2.

Bootmod3 and MHD both fully support the B58 Gen 1. Both deliver the map remotely to the app, which you flash at home. No rolling road, no dealer visit. Samuel recommends the right platform for your goals and setup.

Stage 1 is a custom remap on stock hardware, software only. Stage 2 adds a downpipe and typically an intake, which lets the engine push past the ceiling the stock exhaust side puts on a Stage 1 build. The hardware is not mandatory, but it is the right next step once Stage 1 is not enough.

Keep exploring

Keep exploring B58 Gen 1 tuning

Platform

Bootmod3 (bm3)

Our primary flash platform for B58 Gen 1 builds: app-driven, OTA custom map delivery.

Learn more

Platform

MHD Tuning

The established mobile-app flasher, strong across B58 Gen 1 and turbo BMW builds.

Learn more

By engine

Bootmod3 by engine

Browse bootmod3 stage maps and platform support by engine code, from N55 to S58.

Learn more

By engine

MHD by engine & model

Which BMW engines and models MHD covers, and what each one gets.

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Guide

What is bootmod3?

New to remote flashing? A plain-English explainer on how a custom map reaches your car.

Learn more