Unlock responsive, repeatable performance from your BMW with the JB4 Tuner for B38, B46 and B48 engines. This proven plug and play tuning box from Burger Motorsports delivers serious gains without ECU flashing, works with locked ECUs, and now includes the JB4 PRO Bluetooth adapter and free smartphone app as standard. Ideal as an easy first upgrade or to complement other bolt-ons, the JB4 offers on-the-fly map switching, powerful safety features and OEM-like drivability.
- Plug and play piggyback tuner for BMW B38, B46 and B48 engines
- Gains of up to around 40 whp on a stock B48, with potential for more on higher octane fuel, ethanol blends and cars with supporting modifications
- No ECU flash required and compatible with locked ECUs
- Includes JB4 PRO Bluetooth adapter and free iOS/Android app for map control, logging and firmware updates
- On-the-fly in-dash map switching between stock and performance maps
- Boost by gear for improved traction in lower gears
- Built-in data logging and fault code read and clear
- Direct electronic wastegate control helps prevent throttle closure on cars with freer-flowing exhausts
- Exhaust flap control on most models
- Progressive water/methanol injection support
- Advanced CANbus OBDII integration for smooth, safe power delivery
- Ethanol E85 compatible maps available
- Not VIN-locked, easily removed and resold later
- Rugged billet aluminium enclosure, designed and assembled in the USA
- Runs smoothly like stock and works with all driving modes
- Fuel economy unchanged during normal driving
- 5-year warranty
Map overview: Map 0 stock bypass, Maps 1 to 3 for pump fuel increases, Maps 4 to 5 for higher target boost on high-octane or ethanol blends, Map 6 custom tuning, Map 7 progressive WMI, Map 8 valet/low boost. The JB4 auto-detects B38, B46 or B48 at start-up for a simple set-up experience.
Vehicle compatibility
For BMW models equipped with B38, B46 or B48 engines, including (xDrive where applicable):
- 1 Series: F40 M135i, F40 128ti, F40 118i, F20/F21 116i, 118i, 120i, 125i
- 2 Series: G42 220i, 230i; F22/F23 218i, 220i, 225i, 230i; F44 M235i Gran Coupé
- 2 Series Active Tourer/Gran Tourer: F45/F46 216i, 218i, 220i
- 3 Series: G20/G21 318i, 320i, 320e, 330i, 330e; F30 318i, 320i, 325i, 330i, 330e
- 4 Series: G22/G23/G26 420i, 430i; F32/F33/F36 418i, 420i, 425i, 430i
- 5 Series: G30 530i, 530e
- 6 Series: G32/G33 630i
- 7 Series: G11/G12 730i
- X Series: F48 X1 28i; F47 X2 28i; G01 X3 2.0i; G02 X4 2.0i; G05 X5 30i
- Z4: G29 Z4 20i, Z4 30i
If your BMW has a B38, B46 or B48 engine and you do not see your exact model listed, contact Nforcd for guidance.
What sets JB4 apart
Unlike basic tuning chips, JB4 integrates with multiple sensors and CANbus to safely adjust boost, timing, fuel and trims in real time. You get significant, smooth power gains while retaining factory safety systems, plus full app control and ongoing free firmware updates. It is a favourite at Nforcd for its flexibility, reliability and ease of installation.
Nforcd stocks and supports the JB4 for BMW B38/B46/B48. Order today for fast UK delivery. Professional fitting is available at Nforcd in Warwickshire; request a quote at Sales@nforcd.com.