JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
  • Load image into Gallery viewer, JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
  • Load image into Gallery viewer, JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
  • Load image into Gallery viewer, JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
  • Load image into Gallery viewer, JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)
  • Load image into Gallery viewer, JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)

JB4 Plug-and-Play Piggyback ECU Tuning Box for BMW X3M F97 & X4M F98 2020+ S58 (including Competition)

£1,038.70
£1,038.70
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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 S58-powered BMW with the JB4 plug-and-play tuner for 2020 onward F97 X3M and F98 X4M. This advanced piggyback tuning module delivers quoted gains of 80whp/100wtq on pump fuel and up to 150whp/175wtq on higher octane or E85 blends, all while keeping factory safety systems intact. Both versions now include the free JB4PRO app for iOS and Android.

  • Gains: 80whp/100wtq on pump fuel and up to 150whp/175wtq on higher octane or E85 mixtures.
  • S58-specific tuning: up to 8 preloaded maps for different fuels and modification levels, including ethanol/E85 support.
  • JB4PRO app included: switch maps, view live gauges, log up to 20 parameters, and apply free firmware updates from your smartphone.
  • Launch-friendly control: boost by gear for 1st, 2nd and 3rd, electronic wastegate control, and deep CANbus OBDII integration.
  • Diagnostics and safety: read and clear fault codes while retaining factory safeguards.
  • Easy, reversible fit: true plug-and-play with no cutting, not VIN-locked, smooth OEM-like drivability in all modes, fuel economy unchanged in normal driving, minimum 91 octane recommended, designed and assembled in the USA, 5 year warranty.

JB4PRO board option
Step up to the optional JB4PRO board for built-in Bluetooth, fuel pressure control for more advanced ethanol tuning, onboard data logging memory, and integrated flex fuel, port injection and WMI control via plug-and-play add-on harnesses. Additional features can be unlocked with free firmware updates.

Optional accessories
Flex Fuel and Port Injection harness for direct ethanol sensor input and multi-stage injector control, plus an extension harness that simplifies access to the lower MAP sensor during installation. Available separately.

Vehicle compatibility
- BMW X3M F97 2020+ including Competition
- BMW X4M F98 2020+ including Competition

Order your JB4 tuner from Nforcd, the UK specialist for performance car parts. We know this product well and it has been a popular upgrade for X3M and X4M owners seeking a fast, reversible tuning solution without unlocking or flashing the ECU. Professional fitting is available at Nforcd in Warwickshire. To request a fitting quote, email Sales@nforcd.com.