Ford started with a ‘Mk8’ Fiesta some 71mm longer than the ‘Mk7’, whose front track width had already grown by 30mm compared with that of its predecessor. But the Ford Performance in-house tuning team went wider again on that driven axle, ending up with a whopping 48mm increase on track compared with that of the old Fiesta ST.
Attached to that front axle are several key developments for the car. One of them is the most direct steering rack to be fitted to a front-driven Ford. At 12:1, its gearing is 14% quicker than that of the old ST, though it’s a fixed-ratio system.
Another is a limited-slip differential – the first to be offered on any Fiesta hot hatchback. It is a helical unit supplied by Quaife that works across the front wheels in tandem with a brake-actuated electronic torque vectoring system. The LSD isn’t standard but rather comes as part of Ford’s £850 ST Performance Pack.
The ST adopts derivative-specific front wheel hubs at the bottom of MacPherson-style strut front suspension, with torsion beam suspension at the rear. Damping is via Tenneco RC1 frequency-selective shocks which, though they’re not ‘adaptive’, are effectively double-valved and can switch between softer and firmer settings depending on the profile of the bump being dealt with. This contributes to what Ford’s chassis engineers describe as a more supple quality to the new ST’s ride than that of the last version.