The newly revealed overboost function is a feature of the Focus ST’s turbocharged 2.0-litre four-cylinder EcoBoost powerplant. The function does not affect the engine’s peak outputs of 188kW of power (252hp) and 366Nm of torque (270lb-ft) – rather, it raises torque by as much as 7.4 per cent between 3000-4500rpm, lifting it closer to the engine’s peak level across a broader band of the rev range.
Ford Focus ST US marketing manager Lisa Schoder said the hot-hatch’s engine was supported by a robust cooling system to handle the added performance.
“The turbo itself is specified for sustained, high-output performance, but [our engineers have] programmed the car’s computer to dial in more boost past 3000rpm to give it that extra something,” Schoder explained.
“We limit peak turbo boost to maintain a wide margin of safety and durability over the life of the car. But overboost is cool in that it tweaks more acceleration through the turbo for brief periods for performance-hungry drivers.”
Although Ford says the engine’s overboost function is “just like hitting the turbo-boost button in a video racing game”, the system actually responds to accelerator pedal inputs rather than the press of a big red button or the flick of a switch.
The Ford Focus ST hatch will go on sale in Australia in the final quarter of this year, going head to head with the Mazda3 MPS, Renault Megane RS250 and Volkswagen Golf GTI with an estimated price of $40,000.