The new packages sit at the pinnacle of the long-established Ford tuner’s line-up for the Focus RS, with an extensive list of modifications including the removal of the 2.3-litre Ecoboost unit’s existing turbocharger in favour of “specifically engineered” BorgWarner items.
In the lesser-powered ‘M450’ package - priced from £2950 - the new turbocharger allows an increase of 49bhp over the previous M400 package - up to 444bhp, with 428lb ft of torque. Both figures are considerably more than the recently released (and much more expensive) Mercedes-AMG A45.
As well as the new turbo, Mountune introduces a high-flow sports catalytic converter and exhaust downpipe alongside other ancillary upgrades to be fitted at Mountune’s Brentwood HQ, or available to order online soon.
But that’s just the start; the M520 package uses a more advanced BorgWarner ‘EFR 7163’ turbocharger, alongside an uprated fuel pump, camshafts and valve train. A recalibrated ECU allows this package to take the 2.3-litre engine to 513bhp and 516lb ft.
That kit commands a minimum £5975 price tag and requires substantial internal engine modifications that are said to achieve the output levels “safely and reliably”, but will invalidate the existing warranty of the car, unlike some Mountune upgrade packs.
Mountune doesn’t quote performance times for either pack, but given the latter puts out around 100bhp more than the fastest standard production hot hatchback, we can expect a 0-62mph time of well under four seconds.