Burger Motorsports JB4 Tuner – BMW B58 Gen 1 & Gen 2

OVERVIEW

The JB4 is the fastest way to wake up a B58 without ever touching the factory ECU. It piggybacks the engine's sensor network over CANbus, so the car makes real power while the DME stays stock — no flash, no VIN lock, and no conflict with an over-the-air update. Burger Motorsports quotes power gains of up to 120hp and 120tq to the wheels on a stock B58 running pump gas, with more available on a modified car. Installation takes about 20 minutes with hand tools and it comes back off just as easily.

Pick the generation that matches your engine. Gen1 covers the earlier 2016–2019 B58 and is also offered in a CARB-approved version, which is the one you want if the car has to pass a California visual inspection. Gen2 covers the 2020+ B58 with the revised fuel system.

Both the standard JB4 and the JB4PRO include the JB4PRO Bluetooth adapter and the free app, so wireless map switching, live gauges, datalogging and firmware updates from your phone are standard either way. The JB4PRO is a different board built for heavily modified cars, and it is available on Gen2 cars only. Running stock or bolt-ons, the standard JB4 is the right call; building toward E85, port injection or methanol, go PRO.

SPECS

• Power gains of up to 120hp and 120tq to the wheels on a stock B58 running pump gas
• Map 0: stock tuning — JB4 disabled
• Map 1: +3 psi over stock (91 octane)
• Map 2: +4 psi over stock (91–93 octane)
• Map 3: +6 psi over stock (93+ octane)
• Map 4: absolute target map with a peak target of 20 psi (93+ octane and/or E30)
• Map 5: absolute target map with a peak target of 22 psi (E30+ recommended)
• Map 6: custom user tuning map
• Map 7: progressive water/methanol tuning map
• Map 8: valet / low boost map
• Piggyback tuner — boost is controlled through the sensor network and CANbus, with no ECU flash
• Boost-by-gear control, so timing and boost can be pulled out of 1st and 2nd for traction
• Live gauges, datalogging, and fault code reading and clearing
• Not VIN-locked; roughly 20 minute install and fully reversible
• CARB-approved version available on the Gen1 fitment
• JB4PRO is available on Gen2 cars only
• JB4PRO board adds direct ethanol sensor control
• JB4PRO board adds port injection / CPI / WMI control via the PnP add-on harness
• JB4PRO board adds built-in fuel pressure control for advanced tuning on ethanol mixtures
• JB4PRO board adds onboard datalogging memory
• JB4PRO board adds additional high-current outputs for extra pumps, relays and solenoids
• JB4PRO board adds additional inputs for monitoring external sensors
• JB4PRO board carries Bluetooth and memory on the board itself rather than via the adapter
• JB4PRO board adds CANbus integration with flash tuning
• Free firmware updates for the life of the unit
• 5-year warranty
• Designed and assembled in the USA

PARTS INCLUDED

• JB4 tuner in a billet aluminum enclosure
• Plug and play wiring harness
• JB4PRO adapter for Bluetooth connectivity
• Free JB4PRO smartphone app (iOS and Android)

TECH RESOURCES

Additional Parts Required

• Fuel matched to the map: 91 octane minimum for map 1, 91–93 for map 2, 93+ for maps 3 and 4, and an E30 or stronger ethanol blend for map 5.
• A smartphone (iOS or Android) for the free JB4PRO app. The Bluetooth adapter is included with both the JB4 and the JB4PRO.
• The correct generation selected at checkout — Gen1 (2016–2019) and Gen2 (2020+) boards are not interchangeable, and the CARB-approved unit is a separate Gen1 option.
• On a Gen2 car running a standard JB4 on ethanol, add the JB4 Fuel Pressure Upgrade Kit for direct fuel pressure and fuel trim control. It is not needed on the JB4PRO, and it is not compatible with Gen1 B58.
• A water/methanol injection kit if you intend to run map 7; the JB4 controls the kit but does not include one.
• Port injection, CPI or WMI control on the JB4PRO requires the PnP add-on harness, sold separately.

Installation

• Burger Motorsports B38/B46/B48/B58 Gen1 & Gen2 JB4 Install Guide (PDF)

Notes

• Burger Motorsports does not publish an official part number for this tuner, so no part number is listed. Burger Motorsports lists the 545e, 745e and X5 xDrive45e plug-in hybrids as supported. Gen3 B58 cars take the Gen3 B48/B58 JB4 instead. If you would rather flash the ECU, we also carry the MHD Super License and the bootmod3 tune for the B58.

VEHICLE APPLICATIONS