Unlock serious performance from your 2016 onward Ford Focus RS or Focus ST with the JB4 plug and play tuning box. Working alongside the factory ECU, the JB4 finely adjusts boost, timing and fuelling to sharpen response, cut turbo lag and deliver proven gains of up to 50whp and 60wtq on a stock car. A superb ECU remap alternative, it installs discretely and can be removed without trace. Available from Nforcd.
- Plug and play piggyback tuner that connects to easily accessed engine bay sensors
- High speed 64 MHz processor samples sensors up to 800 times per second via dedicated 10-bit converters for smooth, consistent power delivery
- Full CANbus integration factors in pedal position, throttle, gear, RPM, air/fuel ratio, fuel trims, ignition advance, knock and more for intelligent mapping
- Built-in safety strategies limit boost until oil and coolant are at temperature and automatically drop to a low boost map if the engine overheats, runs lean, knocks or overboosts
- Preloaded with multiple maps including stock and valet; default Map 1 targets around 4 psi over stock peak
- Map switching, data logging, and fault code read/clear via optional diagnostics cable or JB4 Bluetooth app connection
- Ethanol compatible tuning options, including maps for 91 and 93 fuel grades as well as E85 mixtures
- Boost by gear control in 1st, 2nd and 3rd through the app for cleaner launches and traction
- View and record up to 40 live engine parameters within the JB4 app
- Improves 0 to 60 and quarter mile times while maintaining factory-like drivability
- Compatible with all driving modes and typically unchanged fuel economy during normal use
- Not VIN locked so it can be moved to another compatible vehicle or resold later
- Durable billet aluminium enclosure, made in the USA, with a 5 year warranty
Vehicle fitment
- 2016+ Ford Focus RS
- 2016+ Ford Focus ST
Nforcd knows the JB4 platform inside out and it has been a popular upgrade with our customers seeking a fast, reversible performance boost for their Focus RS or ST. Order yours today from Nforcd. Professional fitting is available at Nforcd in Warwickshire. To request a fitting quote, email Sales@nforcd.com.