Tuning · BMW M3 CS (G80)
M3 CS (G80)
S58
The CS treatment for the G80 M3, sharper factory map, stiffer chassis setup, all-wheel-drive only. Hand-calibrated from Stage 1 to a fully bespoke big-turbo build. Same S58 hardware as the standard G80 M3, with a 550 bhp / 650 Nm factory starting point instead of 503 / 650.
BMW M3 CS (G80) tuning
The S58 in the G80 M3 CS is the same twin-scroll twin-turbo straight-six as the standard G80 M3 Competition — same block, same turbos, same MG1 DME architecture. What separates the CS is the factory calibration: BMW shipped it at 550 bhp / 650 Nm versus 503 / 650 on the standard Competition. Samuel starts with the specific car: its fuel grade, installed hardware, and that higher-than-standard factory baseline. Stage 1 revises boost, ignition timing, fuel delivery and torque limits for 650 bhp / 800 Nm from the OEM hardware, flashed in around 15 minutes via the OBD port once the ECU is unlocked. Stage 2 recalibrates around downpipes, midpipe and intakes, targeting 720 bhp / 900 Nm. Stage 3 is bespoke around the hybrid or big-turbo spec you submit.
Engine
S58
Stock
550 bhp · 650 Nm
Stage 3 ceiling
550 bhp
Configurator
Build your M3 CS (G80) 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
About this tune
The G80 M3 CS (2023–present) is the lightweight, sharper-tuned derivative of the G80 M3 Competition — same S58 hardware, more aggressive factory software, stiffer chassis setup. xDrive only, 8-speed M Steptronic only, saloon body only. The Stage 1 and Stage 2 ceilings on the M3 CS are the same as the standard G80 M3 Competition, because the hardware is identical; the CS simply starts from a higher software baseline. Samuel's M3 CS G80 calibration accounts for the CS's stiffer chassis, xDrive logic and the M-DCT gearbox calibration matched to the revised ECU output.
Compatibility
This M3 CS (G80) tune runs on Bootmod3, MHD or MG Flasher — all three flash the S58 over OBD. Compare platforms or see full S58 compatibility.
Engine guide
What the M3 CS (G80) map revision covers: S58 stages explained
The MG1 DME in the G80 M3 CS controls boost pressure, ignition timing, fuel delivery and torque limits — and despite the already-aggressive 550 bhp factory baseline, headroom remains. Stage 1 revises each of those parameters for 650 bhp / 800 Nm from the OEM hardware, flashed via OBD. Stage 2 recalibrates around the expanded airflow from downpipes, midpipe and intakes, targeting 720 bhp / 900 Nm — the same ceiling as the standard G80 M3 Competition because the hardware is shared. Add the Flex Fuel option at Stage 2 for up to 800 bhp on E50 blends. Every file is log-reviewed after the first flash before sign-off.
Stage 1
650 bhp · 800 Nm
No hardware required. The MG1 DME is flashed via the OBD port, boost pressure, ignition timing, fuel delivery and torque limiters all revised. BMW M3 CS Stage 1 unlocks 650 bhp / 800 Nm from the OEM hardware (up from 550 / 650 stock), with a substantially broader torque curve through the mid-range. Same Stage 1 ceiling as the standard G80 M3, the hardware is identical.
Every M3 CS tune Samuel produces is calibrated individually for the specific car, fuel grade and installed hardware, not a base map loaded and left. BMW M3 CS G80 tuning done correctly accounts for the CS chassis stiffness, the M-DCT calibration and UK fuel quality; the map is reviewed against your data logs after the first flash and revised before sign-off.
M3 CS (G80) specs & stage targets
BMW M3 CS (G80) tuning at a glance
- Engine
- S58
- Body styles
- G80 Saloon
- Chassis codes
- G80
- Production
- 2021–present
- Drivetrain
- M xDrive
- Gearbox
- 8-speed M Steptronic
- Stock output
- 550 bhp · 650 Nm
- Tuning ceiling
- ~1500 bhp on the right hardware
| Stage | Target |
|---|---|
| Stage 1 | 650 bhp · 800 Nm |
| Stage 2 | 720 bhp · 900 Nm |
| Stage 3, Hybrid Turbo | 800-1500 bhp depending on spec |
| Stage 3, Big Turbo Kit | 800-1500 bhp depending on spec |
FAQ
M3 CS (G80) tuning — frequently asked questions
Stage 2 on the G80 M3 CS targets 720 bhp / 900 Nm and needs downpipes + midpipe + intakes. The stock S58 turbos, properly fed with the expanded airflow from those three items, reach their real ceiling. Stage 3 requires hybrid or full big-turbo hardware submitted with your full spec.
The S58 in the G80 M3 CS reaches around 1500 bhp on the right hardware spec. Stage 1 and Stage 2 run the stock turbos; beyond that needs a hybrid or full big-turbo conversion with supporting fuelling, and every Stage 3 calibration is built bespoke per car.
The calibrated M3 CS G80 map is delivered to your BM3, MHD or MG Flasher account within 24 hours of payment confirmation. You flash it over OBD yourself in around 15 minutes. It is fully reversible — the original S58 stock file is supplied before you flash, so the car can return to factory calibration at any time.
Yes — G80 M3 CS cars ship with a locked MG1 DME from the factory. The ECU must be unlocked once before any map can be written; after that the car flashes normally over OBD. The unlock is a one-time step and does not affect the tune's reversibility.
A factory warranty can be voided if BMW attributes a specific failure to the tune — that is a personal call. Samuel's M3 CS G80 maps are calibrated to stay within the mechanical limits of the S58 hardware, and the tune is fully reversible to stock before any dealer visit. Many owners run a tuned G80 M3 CS without issue.
Keep exploring
Keep exploring M3 CS (G80) tuning
Other S58 models we tune: M2, M3, M4, M4 CS (G82), X3 M, X4 M.
Engine guide
S58 tuning
Every S58 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 M3 CS (G80), 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 moreBefore you flash
ECU unlock guide
Newer M3 CS (G80) ECUs ship locked from the factory and need unlocking before any tune. Here is how it works.
Learn more