Finally an upgrade kit that adds a high fuel pressure connection to the JB4 for B58 Gen2 and S58 platforms allowing direct control of fuel pressure and fuel trims. Most useful for manual transmission vehicles or those running heavy E85 mixtures on a locked ECU.
It's easy to install and includes a replacement JB4 board and a fuel pressure connector harness that attaches to your existing JB4 harness.
Note this kit is not compatible with Gen1 B58 motors.
Customers who purchased their JB4 new from BMS or an authorized reseller can receive a $75 core refund for their original JB4 board. To take advantage of this core refund ship your original board along with copies of the original JB4 purchase receipt and your JB4 upgrade kit order number to the address on our website. Cores must be received 45 days after upgrade kit receipt to qualify.
For installation directions and additional information click here.
Vehicle Fitment
BMW 2 Series
• 2022+ B58 G42 BMW M240i, M240i xDrive, and M240xi
• 2023+ S58 G87 BMW M2
BMW 3 Series
• 2019+ B58 G20 G21 BMW M340i, M340i xDrive, and M340xi
• 2021+ S58 G80 BMW M3
• 2021+ S58 G80 BMW M3 Competition
BMW 4 Series
• 2021+ B58 G22 G23 G26 BMW M440i, M440i xDrive, and M440xi including Gran Coupe
• 2021+ S58 G82 BMW M4
• 2021+ S58 G82 BMW M4 Competition
• 2022+ S58 G83 BMW M4 Convertible
Toyota Supra
• 2020-2025 GR Supra Mk5 B58 3.0L 6 cyl.
