BMW B38/B46/B48/B58 JB4 Tuner (2024)

The JB4 is the most advanced and highly featured tuning system available for your B58 and B48 vehicle. Power gains are up to 80hp to the wheels (100hp crank) on a completely stock car on pump gas for a B58, and up to 40hp to the wheels (55hp crank) for a B48, gains with bolt-on parts, higher octane, E85 mixtures, and larger turbos are even higher.

The JB4 features a simple plug& play installation harness for easy installation & removal and includes many features not found with any other tune. Including on the fly in-dash map switching between factory and various performance maps, optional in-dash gauge displays for boost, boost limiting by gear for improved traction in lower gears, progressive water/methanol support, built-in data logging, built-in code reading, optional direct EWG control to prevent throttle closure with exhaust modifications, exhaust flapper control, and much more. Other more expensive tuners may claim to equal the JB4's technology but upon closer examination lack most if not all of the JB4's features.

Remember the JB4 does not require any additional modifications or previous stages. Simply install the JB4 as your first and only modification and enjoy an entirely new fast and smooth racing experience. The JB4 also does not require any user setup or customization, but for those who are interested in logging, adding new features as we post them, etc, we suggest the BMS DATA cable or REV3 mobile phone adapter. The JB4 automatically detects between the B46, B48, and B58 models at boot up making installation and setup a snap.

JB4 Map Guide:

Map0: Stock tuning, fully disable JB4
Map1: 3psi over stock added (91 octane)
Map2: 4psi over stock added (91-93 octane)
Map3: 6psi over stock added (93+ octane)
Map4: Absolute target map with peak target of 20psi (93+ and/or 30% E85, EWG connector suggested)
Map5: Absolute target map with peak target of 22psi (30% E85+ fuel, EWG connector suggested)
Map6: Custom tuning map -- see details on JB4tech.com B58 JB4 page
Map7: Progressive WMI map with tuning a function of meth flow and user-defined boost additive.
Map8: VALET / Low Boost Map

Note for 2018-present G chassis vehicles with the digital dash layout we have not yet added in the JB4 commands to allow in-dash control but will provide those via a free firmware update once developed. Until then a JB4 mobile adapter or BMS data cable is required for any map and setting changes.

This B58 JB4 model is compatible with all GEN1 and GEN2 B58 motors. For the newest B58TU2 GEN3 motorrefer to this product page.

JB4_B58 is CARB Approved Under Executive Order (EO) No.D-744-4 for all 2016-2018 BMW 230i, 330i, 430i, 530i, 340i, 440i, 740i, M240i, and X1applications.

Wirelessly connect the JB4 to your Bluetooth 4.0 compatible iOS and Android device via the JB4 Mobile connect kit or to your Windows laptop with the BMS data cable. Both options allow you to record and analyze vehicle and tuning data, change JB4 performance maps, and update JB4 firmware as we release free newer versions with updates, more powerful maps, and new features under development. A separate JB4 Mobile app purchase is also required.

JB4 Power Gains, Features, & Benefits

• Power gains of up to 100hp to the wheels on a stock vehicle
• Improves 0-60 times and 1/4 mile times
•Preloaded with customJB4BMW tuning software and up to 8 maps for various fuel and modification levels
• Ethanol (E85) compatible tuning maps
• Able to read/delete fault codes
•View and record up to 40 different gauges/engine parameters in real time with the JB4 app.
• Boost by gear in 1st, 2nd, and 3rd can be controlled via the JB4 app for a perfect launch
•Exhaust flap operation can be controlled in most JB4 applications
• Compatible with JB4 Mobile for smartphone logging, tuning changes, and adjustment
•The JB4 offers a lot more performance, functionality, and safety than your average performance chip
• Quick Plug & Play Installation
• CANbus OBDII integration offering unrivaled tuning features and performance
• Improved performance over non-integrated chip tunes
• Runs as smoothly as stock, this is how yourvehicleshould have come from the factory
• Compatible with all driving modes
• Fuel economy unchanged during normal driving
• 91 octane fuel or better required for performance gains
• Not VIN locked and can be removed without a trace and resold down the road
•Includes the rugged JB4 billet aluminum enclosure for protection
• Made in the USA
• Free USA Shipping
• 5-year warranty

Vehicle Fitment

Note: If your BMW has a B38/B46/B48/B58 engine and you don't see your exact model on the list below please email us.

BMW 1 Series
• 2020-Present F40 B48BMW128ti
• 2019-Present F40 B48 BMWM135i
• 2019-2019F40 B38 BMW118i
• 2015-2019 F20/F21 B58 BMWM140i
• 2016-2019 F20/F21 B48 BMW120i, 125i
• 2015-2019 F20/F21 B38 BMW116i,118i

BMW 2 Series
• 2022-Present G42 B58 BMWM240i including xDrive
• 2022-Present G42 B48 BMW220i, 230i
• 2016-2021 F22 F23 B58BMWM240i including xDrive
• 2017-2021 F22 F23 B48 BMW230iincluding xDrive
• 2017-2021 F22 F23 B48 BMW225iincluding xDrive
• 2017-2021 F22 F23 B46 BMW220iincluding xDrive
• 2015-2021F22 F23 B38 BMW218i
• 2015-2021 F45 F46 B38 BMW216i Active tourer and GT
• 2014-2020 F45 F46 B38 BMW218i, 220iActive tourer andGT
• 2019-Present F44 B48 BMWM235iGran Coupéincluding xDrive

BMW 3 Series
• 2020-Present G20 G21 B58BMWM340iincluding xDrive
• 2019-PresentG20 G21 B46 B48 BMW318i, 320i, 320Li, 320e, 330i, 330e, 320Liincluding xDrive
• 2016-2018 F30 B58 BMW340iincluding xDrive
• 2016-2018 F30 B48 BMW330i, 330eincluding xDrive
• 2016-2018F30 B48 BMW325iincluding xDrive
• 2016-2018 F30 B46 BMW320iincluding xDrive
• 2016-2018F30 B46 BMW318iincluding xDrive BMW 4 Series
• 2021-Present G22 G23 G26 B58 BMWM440iincludingGran Coupe and xDrive
• 2021-Present G22 G23 G26 B48 BMW420i, 430iincludingGran Coupe and xDrive
• 2016-2020 F32 F33 F36 B58 BMW440iincludingGran Coupe and xDrive
• 2016-2020 F32 F33 F36 B48 BMW430iincludingGran Coupe and xDrive
• 2016-2020 F32 F33 F36 B48 BMW425iincludingxDrive
• 2016-2020 F32 F33 F36 B46 BMW420iincludingxDrive
• 2016-2020F32 F33 F36 B38 BMW418i

BMW 5 Series
• 2017-Present G30 B58 BMW540iincludingxDrive
• 2017-Present G30 B46 BMWB48 530i 530eincludingxDrive
• 2021-PresentG30 BMW545e

BMW6 Series
• 2018-Present G32 G33B48 B58 BMW630i 640iincludingxDrive

BMW7 Series
• 2016-2022 G11 G12 B58 BMW 740i includingxDrive
• 2016-2022G11 G12 B48BMW730iincludingxDrive

BMW8 Series
• 2020-Present G15 G14 G16 B58 BMW840iincludingGran Coupe and xDrive

BMW X Series
• 2016-2022 F48 B46 B48BMWX1 28i including xDrive
• 2018-Present F47 B46 B48 BMWX228iincluding xDrive
• 2018-Present G01 B48 B58 BMWX3 2.0i,X3 3.0i,X3 M40iincludingxDrive
• 2019-PresentG02 B48 B58 BMWX4 2.0i,X43.0i,X4M40iincludingxDrive
• 2019-2022G05 B58 BMWX540iincludingxDrive
• 2021-2022 G05 B48BMWX5 45eincludingxDrive
• 2020-Present G06 B58 X6 40i xDrive
• 2019-2022 G07 B58 BMWX7 40iincludingxDrive

What is a JB4?

The JB4 is a plug & play tune available for turbocharged vehicles. The JB4 tuner installs between your car's sensors and the DME/ECU (computer) and manipulates vehicle performance through these connections making your vehicle much faster. While it's not the only tuning system that operates this way the JB4 separates itself from the competition with much more advanced connection points and processing including CANbus, fuel & spark control, Bluetooth to your smartphone, and a variety of innovative and advanced features not possible with any other system. BMS regularly publishes free mapping and firmware updates adding performance and features as ongoing development allows. In addition, the JB4 system is not VIN-locked to your vehicle and can quickly be removed and swapped between cars or resold at a later time. Often imitated but never duplicated the JB4 has been the gold standard in plug and play turbocharged performance tuning for over a decade.