You do not need a full build to make your Focus RS feel faster. Small changes add real gains. The trick is to pick parts that give power now and let you step up later. Here are the best Focus RS upgrades that complement the hot-hatch’s rally-bred roots.
Start with ECU Tuning and Ethanol
An ECU tune is the single biggest bang for your buck. A professional tune or a proven off-the-shelf handheld tuner will adjust timing, adjust boost, and optimize your RS’s performance. If you run E30 or E85, the gains jump higher and the motor runs cooler under boost.
Wastegate Actuator and Boost Control
Swapping the wastegate actuator or fitting an adjustable unit gives more boost at lower RPM. That helps midrange torque where the RS feels lazy. It sits just behind tuning and ethanol as a top power item among Focus RS enthusiasts. Paired with a tune, an upgraded actuator is cheap and highly effective.
Exhaust Upgrades, Downpipe and Cat
A high-flow downpipe and a less restrictive midpipe reduce back pressure. That lets the turbo spool easier. Real-world driver reviews put the downpipe as one of the next-best power items after tune, actuator ,and ethanol. Combine this with a cat-back, and you will see a smoother spool and more top-end power.
Intercooler and Air Intake
The Focus RS runs hot when pushed. A larger front-mount intercooler (FMIC) keeps air charge temps down. That preserves power over repeated runs or long climbs. People in warm climates saw the biggest gains from an upgraded intercooler and an upgraded intake to reduce intake air temperatures.
Methanol Injection and Fueling
Methanol injection helps control detonation and helps lower intake temps. It is useful if you push boost or use E85. Methanol is a solid mid-tier upgrade for consistent power at higher boost levels. Remember, fueling and a proper tune must match any methanol system.
Bracing, Motor Mounts and Driveline Feel
The RS delivers big torque to the wheels. Even though it uses a sophisticated Torque-Vectoring All-Wheel-Drive system, the driveline feel can be improved with simple mods. The stock rear motor mounts are soft for the power levels. Upgrading rear motor mounts improves shift feel and reduces wheel hop. This is not a power mod, but it makes the car feel quicker, and more planted. It turns engine torque into forward motion more effectively.
How Much Power to Expect?
An ECU tune, intake and downpipe give roughly 40 to 60 wheel horsepower, depending on fueling and supporting mods. Add E30 or E85 with proper fueling and you can push into the 70 plus wheel horsepower range over stock on a conservative build. Going past 400 wheel horsepower needs a larger turbo, upgraded fuel system and more upgraded internals.
FN Tuned Throttle Response Controller for Focus RS
The Focus RS comes from the factory with conservative throttle mapping and a dull throttle response, despite being an almost-exotic hot hatch. Ford does this for emissions, drivability, and protection. The result is a slight delay between your pedal input and the engine’s reaction.
The FN Tuned Throttle Response Controller is the fix for that. It connects directly to the accelerator pedal sensor and adjusts the drive-by-wire signal before it reaches the ECU. Nothing inside the ECU is changed. Power output stays the same. What changes is how quickly the engine responds to your input.
FN Tuned gives you four driving modes, each with nine adjustment levels. That adds up to 36 different throttle maps. You can run a softer setting for efficient daily driving, then switch to a sharper response for spirited driving.
Installation is simple and takes about 15 minutes. It is fully plug-and-play, with no cutting or permanent changes. The module stays tucked away in the footwell and is controlled through your phone. It also includes a subscription-based Anti-Theft feature that locks the throttle pedal through the app when you want extra security.
Click HERE to order your FN Tuned throttle response controller!
FN Tuned does not add horsepower. But it makes the car feel more dynamic and connected. It is fully compatible with other Focus RS upgrades and helps you get more out of future power mods by improving throttle response and control.
Pro Tips and Priorities
Start with a proven tune. Run an upgraded wastegate actuator next. Move to cooling and airflow parts, like an intercooler and a high-flow intake. Add a quality downpipe and match the tune. Use meth or switch to ethanol when you want the next step. Upgrade engine mounts and brakes to keep the car usable.
Images: Ford Newsroom