The m365 upgrade kit starts from £689 and can be equipped to current, fourth-generation Focus ST models. Performance is boosted from 273bhp to 350bhp while peak torque is increased by 103lb ft to 413lb ft.
The upgrade is a second-stage modular update which adds on to the original m330 tuning kit. A high-flow panel air filter and bespoke 3.0in high-flow downpipe are added as per the previous upgrade, with a sports catalyst and new Sport GPF to reduce exhaust back-pressure.
The kit can be configured in one of four driving modes: m365 performance, m330 performance, stock performance and anti-theft. Customers can choose their calibration and install the kit using Mountune’s Bluetooth OBD dongle and SMARTflash app on smartphones or tablets.
“Ford has done a great job with the stock ST and what we have done with this m365 upgrade kit is to fully optimise the calibration with our newly engineered low-back pressure exhaust hardware,” said David Mountain, Mountune boss.
“This means maximum performance is available throughout the rev range and it’s now a seriously fast car, which is also great fun to drive,” he said.
A custom track setting is also included as part of the upgrade with an improved wet weather mode, along with an enhanced exhaust note and a more aggressive launch control system.
It’s the third tuning kit to be released this year by the firm, which introduced the m260 kits to give the Fiesta ST and Puma ST a performance boost to 256bhp.