An upgraded ECU and high-flow induction kit should do the trick.
The Ford Focus RS comes from the factory with all-wheel drive, a turbocharged engine, and as much as 350 horsepower (260 kilowatts)… but you already knew that. Even with all that speed straight from the factory, one tuner thinks that the hot hatch needs even more fire power. Mountune out of the U.K. has introduced an M400 upgrade for the Focus RS.
Last August, fresh off the debut of the Focus RS, the company introduced a similar upgrade that brought power from 350 hp (260 kW) and 350 pound-feet (474 Newton meters) of torque to 375 hp (276 kW) and 376 lb-ft (510 Nm). A custom air filter, a new air re-circulation valve, and an upgraded ECU were in part to thank. This new upgrade is similar, but manages to pull an extra 25 horses (18 kW) out of the 2.3-liter EcoBoost engine.
Using a selection of custom software, Mountune's Ford Focus RS is able to achieve 400 hp (298 kW) and 413 lb-ft (560 Nm) of torque at the crank. Features like a high-flow induction kit, an upgraded turbo re-circulation valve, a high-flow hard pipe, and a high-performance alloy intercooler bring the power up, as well as an upgraded ECU.
With the new go-fast package equipped, Mountune says that the Focus RS will be improved on 0-60 times, quarter-miles times, as well as overall straight line speed, though the company doesn’t give any specific figures. With the previously mentioned M375 upgrade equipped, the Focus RS was able to shed 0.2 seconds off its 0-60 time en route to the same 165 mph (266 kmh) top speed.
The Mountune M375 kit for the Focus RS asks £899 ($1,170) and is available in the U.K and select European markets. The latest M400 upgrade will set you back a bit more with an asking price of around £3,000 ($3,905) for buyers in the U.K. and Europe.