Tuning · BMW 330i (G20 / G21)
330i
B48
The B48 in everyday saloon form. Hand-calibrated from Stage 1 through to a hybrid-turbo build. The B48 is sharper than its reputation when calibrated correctly.
Engine
B48
Stock
255 bhp · 420 Nm
Stage 3 ceiling
255 bhp
BMW 330i tuning
Most buyers who want a properly quick G20 without six-cylinder money end up in a 330i, which makes it the volume performance pick of the current 3 Series — and one of the cars Samuel maps most often. It is brisk from the showroom, but the B48 in this state of tune still carries plenty of software headroom, and owners tune it to close the gap to the six-cylinder cars without changing cars.
Stock, the 330i makes 255 bhp and 420 Nm. Samuel's Stage 1 recalibration takes the same hardware to 310 bhp and 520 Nm, keeping the factory smoothness while filling in the mid-range where the standard map tails off. Add a downpipe and intake and Stage 2 lifts the target again to 340 bhp and 550 Nm, still on the original turbo.
Past Stage 2, hybrid and full-frame turbo builds carry the 330i to roughly 500 bhp with supporting fuelling, each one calibrated around the owner's exact parts list. The whole process happens wherever the car is parked: Samuel writes the file, it lands in your BM3, MHD or MG Flasher account inside 24 hours, and you keep the saved stock map for a full return to standard.
Configurator
Build your 330i 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
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Engine guide
BMW 330i tuning, stages, hardware and what to expect from the G20 B48
The G20 330i runs the higher-output B48, same block, head and turbo as the 320i, with BMW's standard 255 bhp / 420 Nm software calibration and the full injector spec. BMW 330i tuning with Samuel targets the stock turbo's real capability, which sits comfortably above the factory figure. The hardware ceiling is identical between the 330i, 430i and 530i, only the chassis weight and gearbox calibration vary slightly. BMW 330i G20 tuning (saloon) and BMW 330i G21 Touring tuning use the same map.
Stage 1
310 bhp · 520 Nm
No hardware required. The MG1CS003 / MEVD17 DME is flashed via the OBD port, boost pressure, ignition timing, fuel delivery and torque limiters all revised. BMW 330i Stage 1 unlocks 310 bhp / 520 Nm from the OEM hardware (up from 255 / 420 stock), with a noticeably broader torque curve and sharper throttle response. The BMW 330i chip tuning starting point for almost every owner.
Every 330i tune Samuel produces is calibrated individually for the specific car, fuel grade and installed hardware, not a base map loaded and left. BMW 330i tuning done correctly accounts for the G20 chassis 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
Platform and hardware compatibility
Bootmod3 (BM3)
Full B48 support across every chassis in the family (320i, 330i, 420i, 430i, 530i, Z4 sDrive20i). OBD-port flashing on the MEVD17 (early) and MG1CS003 (later) DMEs. Realtime monitoring via the BM3 app, the most widely used platform for B48 tuning.
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MHD
Full B48 support. Suitable for Stage 1 and Stage 2 across the family. Strong data-logging toolset for verifying lambda, ignition correction and intake temperatures after each flash.
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MG Flasher
Full B48 support. Clean interface and reliable flash process on the MG1CS003 DME, a common choice for owners who prefer the MG ecosystem.
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xHP Flashtool
Compatible with the ZF 8HP gearbox fitted to every modern B48 chassis (G20 / G22 / G30 / G29). Available as an add-on, strongly recommended at Stage 2 where torque jumps significantly for a 2.0-litre four. Manual-gearbox cars do not need xHP.
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ECU: MEVD17 / MG1CS003 DME across B48 production. Accessible via the OBD port, no bench flash required for Stage 1 or Stage 2.
330i specs & stage targets
BMW 330i tuning at a glance
- Engine
- B48 · 2.0L turbocharged inline-four
- Body styles
- G20 Saloon · G21 Touring
- Chassis codes
- G20 / G21
- Production
- 2019–present
- Drivetrain
- Rear-wheel drive
- Gearbox
- 8-speed ZF automatic
- Stock output
- 255 bhp · 420 Nm
- Tuning ceiling
- ~500 bhp on the right hardware
| Stage | Target |
|---|---|
| Stage 1 | 310 bhp · 520 Nm |
| Stage 2 | 340 bhp · 550 Nm |
| Stage 3, Hybrid Turbo | Up to 500 bhp depending on spec |
| Stage 3, Big Turbo Kit | Up to 500 bhp depending on spec |
FAQ
330i tuning — frequently asked questions
Stage 1 moves the 330i from its factory 255 bhp and 420 Nm to 310 bhp and 520 Nm without touching the hardware. The extra 100 Nm arrives through the mid-range, which is where the standard calibration feels most restrained, so the everyday difference is larger than the headline numbers suggest.
At Stage 2 the 330i runs 340 bhp and 550 Nm, which puts it firmly into six-cylinder territory in real-world driving, in a lighter and cheaper-to-run four-cylinder package. The B58 cars still hold the outright ceiling advantage, but for most owners a mapped 330i delivers the pace they were shopping the M340i for.
Only a downpipe and an intake. With those two parts breathing for it, the standard turbo supports Samuel's Stage 2 calibration of 340 bhp and 550 Nm on the 330i. Nothing else on the engine needs changing at this level, which keeps Stage 2 one of the best value-per-pound steps on the platform.
BMW can decline a warranty claim on a failure it can attribute to a tune, so treat it as a judgement call. Two things work in your favour: Samuel calibrates the 330i within the known limits of the B48's standard components, and the map can be flashed back to the saved stock file before a dealer visit. Plenty of G20 owners run mapped daily cars on that basis.
Because the file is built for your car either way — remote just removes the travelling. You supply the build details, Samuel hand-calibrates the map, and you flash it yourself through the OBD port with BM3, MHD or MG Flasher. Datalogs can be reviewed afterwards and the calibration refined, so the tune is dialled in on the roads you actually drive.
Keep exploring
Keep exploring 330i tuning
Other B48 models we tune: G20 320i, 330e, G22 420i, 430i, 530e, 530i.
Engine guide
B48 tuning
Every B48 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 330i, 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