Tuning · BMW Z4 M40i (G29)
Z4 M40i
B58 Gen 2
A roadster with the Gen 2 B58 underneath. 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 2
Stock
382 bhp · 500 Nm
Stage 3 ceiling
382 bhp
About this tune
The G29 Z4 M40i (2019-present) is the third-generation Z4 roadster with the B58 Gen 2 underneath, and the BMW half of a joint platform shared with the Toyota Supra 3.0. Stock is 382 bhp / 500 Nm, sent rear-wheel via the ZF 8HP. The G29's lower kerb weight (compared to the M340i saloon) means the Stage 1 / Stage 2 torque jump translates into very noticeable in-chassis performance, and it shares its hybrid-turbo and big-turbo aftermarket directly with the Supra.
BMW Z4 M40i tuning
The B58 Gen 2 in the G29 Z4 M40i is the same 3.0-litre single-turbo straight-six fitted to the M340i, M440i, X3 M40i and Toyota Supra 3.0 — same MG1CS003 DME, same hardware ceiling. The G29 is the lightest car in the B58 Gen 2 family, rear-wheel drive only, and shares its hybrid-turbo and big-turbo aftermarket directly with the Supra. Samuel calibrates the Z4 M40i for the G29 roadster specifically — the lower kerb weight and RWD-only drivetrain shape how the calibration is built. Stage 1 targets 440 bhp / 680 Nm from OEM hardware; Stage 2 adds downpipe (OPF delete if applicable) and intake for 480 bhp / 700 Nm. Every file hand-calibrated for the specific car — not the B58 Gen 2 family average.
The G29 Z4 M40i (2018–present) is the third-generation Z4 roadster — B58 Gen 2 straight-six, RWD, 8-speed ZF 8HP automatic, built on a shared platform with the Toyota Supra 3.0. The Z4 M40i is lighter than the M340i saloon and considerably lighter than the X3 M40i SUV; the Stage 1 torque gain of 180 Nm translates more directly into chassis movement than in any other B58 Gen 2 body. xHP gearbox calibration is available as an add-on and is recommended at Stage 2 and above on the ZF 8HP.
Configurator
Build your Z4 M40i 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
£0
Engine guide
What the Z4 M40i map revision covers: B58 Gen 2 stages explained
The G29 Z4 M40i is the most responsive B58 Gen 2 chassis — lightest body, RWD only, shared platform with the Supra. Samuel calibrates the Z4 M40i for the roadster's specific characteristics: the RWD torque delivery, the lighter chassis behaviour and the 8HP gearbox mapping. Stage 1 targets 440 bhp / 680 Nm from OEM hardware — 58 bhp / 180 Nm gained with no mechanical changes. Stage 2 adds downpipe (OPF delete if applicable) and intake for 480 bhp / 700 Nm. The TU fuel pump is factory-fitted on all B58 Gen 2 cars, so no additional pump upgrade is required. Stage 3 is bespoke around whatever hybrid or big-turbo spec is submitted. Every map is log-reviewed after the first flash before sign-off.
Stage 1
440 bhp · 680 Nm
No hardware required. The MG1CS003 DME is flashed via the OBD port. BMW Z4 M40i Stage 1 unlocks 440 bhp and 680 Nm from the OEM hardware (up from 382 / 500 stock). The BMW Z4 G29 tuning starting point, the most cost-effective change you can make to the roadster.
Every Z4 M40i tune Samuel produces is calibrated individually for the specific car, fuel grade and installed hardware, not a base map loaded and left. BMW Z4 M40i tuning done correctly accounts for the G29 roadster behaviour, 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
This Z4 M40i tune runs on Bootmod3, MHD or MG Flasher — all three flash the B58 Gen 2 over OBD. Compare platforms or see full B58 Gen 2 compatibility.
Z4 M40i specs & stage targets
BMW Z4 M40i tuning at a glance
- Engine
- B58 Gen 2
- Body styles
- G29 Roadster
- Chassis codes
- G29
- Production
- 2018–present
- Drivetrain
- RWD
- Gearbox
- 8-speed ZF automatic
- Stock output
- 382 bhp · 500 Nm
- Tuning ceiling
- ~1000 bhp on the right hardware
| Stage | Target |
|---|---|
| Stage 1 | 440 bhp · 680 Nm |
| Stage 2 | 480 bhp · 700 Nm |
| Stage 3, Hybrid Turbo | 550-1000 bhp depending on spec |
| Stage 3, Big Turbo Kit | 550-1000 bhp depending on spec |
FAQ
Z4 M40i tuning — frequently asked questions
Stage 1 on the Z4 M40i (G29) targets 440 bhp / 680 Nm from the 382 bhp / 500 Nm factory baseline — 58 bhp / 180 Nm gained from the OEM B58 Gen 2 hardware. The MG1CS003 DME is flashed via the OBD port on BM3, MHD or MG Flasher in around 15 minutes.
This page covers the G29 Z4 M40i Roadster (2018–present), RWD only, ZF 8HP automatic. The G29 shares its platform with the Toyota GR Supra 3.0 — the Supra has its own page. Every tune Samuel delivers is calibrated for the specific car, its fuel grade and installed hardware.
Stage 2 on the G29 Z4 M40i targets 480 bhp / 700 Nm and needs downpipe (OPF delete if applicable) + intake. The TU fuel pump is factory-fitted on all B58 Gen 2 cars; no additional pump upgrade is needed.
The B58 Gen 2 in the G29 Z4 M40i reaches around 1000 bhp on the right hardware spec — the same ceiling as any other B58 Gen 2 chassis, because the engine hardware is identical. Stage 1 and Stage 2 run the stock turbo; beyond that is bespoke per car.
Yes — xHP gearbox calibration is available as an add-on for the ZF 8HP automatic fitted to the Z4 M40i. It delivers firmer, faster shifts, raised torque limits and launch control logic matched to the ECU map. Recommended at Stage 2 and above where the additional torque is most pronounced in the lighter RWD roadster chassis.
Keep exploring
Keep exploring Z4 M40i tuning
Other B58 Gen 2 models we tune: M240i, M340i, M440i, X3 M40i, X4 M40i, Supra 3.0.
Engine guide
B58 Gen 2 tuning
Every B58 Gen 2 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 Z4 M40i, 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