Power gains of up to 100hp on a stock vehicle without the risks of flashing!
Units shipped 3/5/2021 or later include a free electronic wastegate (EWG) connector preinstalled in the JB4 harness!
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 n54tech 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+ 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.
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 X1 applications.
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. Separate JB4 Mobile app purchase 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 custom JB4 BMW 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 your vehicle should 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
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.
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
• 2019+ F40 B48 M135i
• 2019+ F40 B38 M118i
• 2015+ F20 F21 B58 M140i
• 2016+ F20 F21 B48 120i, 125i
• 2015+ F20 F21 B38 116i
• 2015+ F20 F21 B38 118i
BMW 2 Series
• 2016+ F22 F23 B58 M240i/iX
• 2017+ F22 F23 B48 230i/iX
• 2017+ F22 F23 B48 225i/iX
• 2017+ F22 F23 B46 220i/iX
• 2015+ F22 F23 B38 218i
• 2015+ F45 F46 B38 216i Active tourer and GT
• 2014+ F45 F46 B38 218i, 220i Active tourer and GT
• 2019+ F44 M235i/iX
BMW 3 Series
• 2020+ G20 G21 B58 M340i/M340iX
• 2019+ G20 G21 B46 B48 318i/320i/320Li/320e/330i/330iX/330e/320Li
• 2016-2019 F30 F31 F34 B58 340i/340iX
• 2016-2018 F30 F31 F34 B48 330i/330iX/330e
• 2016-2018 F30 F31 B48 325i/325iX
• 2016-2018 F30 F31 B46 320i/320iX
• 2016-2018 F30 F31 B46 318i/318iX
BMW 4 Series
• 2021+ G22 G23 G26 B58 440i/440iX/Gran Coupe
• 2021+ G22 G23 G26 B48 420i/430i/430iX/Gran Coupe
• 2016-2020 F32 F33 F36 B58 440i/440iX/Gran Coupe
• 2016-2020 F32 F33 F36 B48 430i/430iX/Gran Coupe
• 2016-2020 F32 F33 F36 B48 425i/425iX
• 2016-2020 F32 F33 F36 B46 420i/420iX
• 2016-2020 F32 F33 F36 B38 418i
BMW 5 Series
• 2017+ G30 G32 B58 540i/540iX
• 2017+ G30 G32 B46 B48 530i/530iX/530e
BMW 6 Series
• 2018+ G32 G33 B48/B58 630i/640i/640iX
BMW 7 Series
• 2016+ G11 G12 B58 740i/740iX
BMW 8 Series
• 2019+ G14 G15 G16 B58 840i/840iX/Gran Coupe
BMW X Series
• 2016+ B46/B48 X1
• 2018+ B46/B48 X2
• 2018+ G01 B48/B58 X3 2.0i/3.0i/M40i including xDrive and sDrive
• 2019+ G02 B48/B58 X4 2.0i/3.0i/M40i including xDrive and sDrive
• 2019+ G05 B58 X5 40i/40iX
• 2019+ G06 X6 40iX
• 2019+ G07 B58 X7 40i
• 2019+ BMW G29 B58 Z4 M40i
• 2019+ BMW G29 B46/B48 Z4 30i and Z4 20i
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.
By purchasing this item, you acknowledge that this item is ineligible for a refund, return, or exchange. Please view our Return Policy for more information.