JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
  • Load image into Gallery viewer, JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
  • Load image into Gallery viewer, JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
  • Load image into Gallery viewer, JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
  • Load image into Gallery viewer, JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines
  • Load image into Gallery viewer, JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines

JB4 Plug and Play Piggyback ECU Tuning Box Performance Tuner for BMW Gen 3 B48 & B58 SENT Engines

£908.70
£908.70
Sold out
Tax included. Shipping calculated at checkout.

Heads-up on cancellations & returns: if you cancel an order or return an item, you won't get back 100% of what you paid. We apply a 10% restocking fee, the outbound shipping is non-refundable, and we have to pass on Shopify / PayPal payment processing fees; these aren't returned to us when we refund you. International orders also lose on exchange-rate spread in both directions. If the original packaging is damaged or missing, a reboxing charge applies. For international orders specifically, if you refuse to pay our shipping invoice or supply a prepaid label after placing the order, the same deductions apply. We're upfront about this — please be sure of your purchase before ordering.

Unlock serious performance from your BMW Gen 3 B48 or B58 engine with the JB4 plug and play tuning box. Designed for the latest SENT-equipped Gen 3 platforms, the JB4 delivers rapid, real-time control without the risks of ECU flashing. Expect gains of up to 130whp on a stock vehicle with the right fuel, with smooth factory-like drivability and the flexibility to tailor power using preloaded maps.

  • Up to 130whp gains on a stock car, with further potential when using compatible ethanol blends
  • True plug and play harness for quick install and removal, not VIN locked and removable without trace
  • Processes ultra-fast SENT digital signals and integrates via CANbus OBDII for precise, zero-latency control
  • On-the-fly map switching, boost by gear for improved traction, and progressive water/methanol support
  • Built-in data logging and fault code read/clear, with the optional JB4 PRO Bluetooth app to monitor up to 40 parameters
  • Rugged billet aluminium enclosure, designed and assembled in the USA, with a 5-year warranty

Preloaded with custom maps for various fuel qualities and modification levels, the JB4 runs as smoothly as stock, works with all driving modes, and typically leaves fuel economy unchanged during normal driving. For performance gains, 91 octane fuel or better is required. Firmware updates and new features are released regularly via the JB4 PRO app, keeping your tune current.

Vehicle fitment: Gen 3 B48/B58 only
This JB4 is specifically for the latest Gen 3 B48 and B58 engines that use updated connectors and SENT sensors. It does not plug into earlier B48/B58 engines.

Supported models
BMW 2 Series: 2023+ F44 228i xDrive Gran Coupe
BMW 3 Series: 2025+ G20/G21 B58 M340i including xDrive; 2025+ G20/G21 B48 330i, 330e, 320i including xDrive
BMW 4 Series: 2025+ G22/G23/G26 B58 M440i including Gran Coupe and xDrive; 2025+ G22/G23/G26 B48 420i, 430i including Gran Coupe and xDrive
BMW 5 Series: 2024+ G60/G61 B58 540i including xDrive; 2024+ G60/G61 B48 530i, 530e including xDrive
BMW 7 Series: 2023+ G70 B58 740i
BMW X Series: 2023+ U11/U12 B48 X1 28i and xDrive28i; 2025+ G45 B58 X3 M50 xDrive; 2024+ G05 B58 X5 M40i and xDrive40i; 2024+ G06 B58 X6 xDrive40i; 2022+ G07 B58 X7 xDrive40i

Nforcd knows the JB4 platform inside out and it has proven popular with our BMW customers seeking a powerful, reversible upgrade. Order online today, or book professional installation with Nforcd in Warwickshire. Fitting is available on request; email Sales@nforcd.com for a quote.