Per the manufacturer, the K&N 69-3539TB Typhoon is a mandrel-bent aluminum intake that replaces the factory filter, intake tube, and air box on the 2.3L EcoBoost in the Ford Focus RS. Under the hood, the 2.3L is an all-aluminum four-cylinder with dual overhead cams and Ti-VCT, and its boost comes from a Honeywell twin-scroll turbo. The kit ships with a washable, reusable high-flow filter and a heat shield, and the tube has a Candy Blue powder coat. Its main purchase case is measurable airflow: the manufacturer's chassis dyno comparison reported an estimated gain from 224.46 to 258.47 wheel horsepower, with the intake as the only change. Owners on user forums are more skeptical, and one thread argues that the factory setup already flows well, so the real-world case rests on the measured gain, throttle response, and a filter the manufacturer rates for up to 100,000 miles.
Fitment and legality deserve a close look before you buy. The manufacturer's product page lists the kit for 2016-2018 Focus RS models, while its install blog refers to 2016 and 2017 cars, so confirm your model year. The product page also lists CARB EO D-269-70 and says the kit is legal in all 50 states. However, the manufacturer's general legal notice warns that some K&N intake systems with 69- prefixes are not street legal in some states that have adopted CARB emission standards. Check the EO against your year and state. Searchers looking for a 2016 2017 Focus RS 2.3 EcoBoost cold air intake, a Candy Blue Typhoon intake, or a K&N 69-3539TB upgrade will find those specifics in the spec list below.
The manufacturer lists CARB EO D-269-70 for this kit, but its general notice says some 69-prefix K&N intakes are not legal in CARB-adopting states. Confirm the EO covers your exact model year and state before purchase.
Per the manufacturer, the kit replaces the factory air filter, intake tube, and air filter housing, and step-by-step photo instructions come in the box.
The manufacturer's dyno comparison shows an estimated gain of about 33 hp at the wheels. Owners on user forums question how much of that is noticeable on the street, so treat the figure as the manufacturer's test result rather than a guarantee.
The manufacturer describes installation as straightforward and usually completed in about 90 minutes or less, using the factory mounting points and common hand tools. The heat shield is designed to use the factory mount locations, so the job is mostly a bolt-on process. One gotcha raised on Focus forums: an early K&N unit had its heat-shield MAF opening punched off-center, leaving the sensor housing not centered in the hole. Dry-fit the heat shield and sensor before final tightening, and check whether your kit has the revised hole placement.
