The mountune m400X optimises all available headroom on the Mk3 Focus RS, to provide the most exhilarating performance available whilst retaining the OE turbocharger.
Due to the increased cylinder pressures, this calibration should not be used on vehicles that have not been upgraded with forged pistons, steel conrods and that are using a colder spark plug. 97RON+ fuel should also be used to maintain performance.
This option is for customers who already have the hardware required for m400X installed and require an mTune handset with calibration(s), or that want to upgrade their existing m375, m380 or m400 mTune to m400X firmware - please select from the drop down below.
Required m400X Hardware
Please Note: The warranty of the vehicle being updated with this upgrade may be affected. The m400X upgrade kit is not Ford-endorsed.
To maintain any warranty provision otherwise entitled to you, and to ensure correct operation and reliability, calibrations loaded via an mTune handset must be installed together with the correct mountune® hardware.
NOT COMPATIBLE with vehicles in North America. Please visit our US website for compatible Focus RS products - www.mountuneusa.com
had the 400x fitted today with all the other supporting mods on the car going from fpm375 to 400x shockingly fast even from standstill it pulls hard , mid range you have to have a firm grip on that steering wheel really impressed well done the mountune team
After a full Mountune engine rebuild last year (original engine self-destructed on track), the car has performed well on track days with the M400 map. Last month the map was upgraded to M400X which impressed straight away on the drive home, matching 2 bikes off the lights until I backed off – pretty sure it wouldn’t have done that before! The proper test is now complete following a track day at Donington. The amount and spread of torque across the rev range is incredible compared to the basic M400 map. The power delivery gives you the impression it has around 450-475BHP, in fact it is so good that I believe any more power would ruin the balance of the car. Mountune have definitely hit the sweet spot with this conversion, turning this RS into a track beast! Roll on the next track day.
Had the M400X flashed today in conjunction with 500 mile oil change post forged internals fitted last January. Steady driving for next few weeks before I can unleash the beast.