18 bhp from swapping to a cotton gauze filter....if only tuning was really that easy LOL
I have been improving my engines for years, including developing an induction kit for a couple of brands and in reality you would be lucky to get 1 or 2 bhp out of it.
A paper filter will flow more than sufficient air to feed the engine and filter it better than a cotton gauze, yes the cotton gauze will feed more but the engine can't suck/use it is what is the point (other than a bit more noise). Also looking at the video the filter etc they remove do not any different to what is in the Focus ST 2.0 ecoboost chucking out 250bhp, if the filter can feed enough air got that then it surely can for the 1.6
I have spent more than I care to remember on air filters over the years but I do it in the knowledge it will in reality do little for performance I tell I do some real tuning to the car where by the standard induction does become restrictive.
Car 1 mkII focus ST (Volvo T5 lump) remapped to 285 bhp (done purely for astetics)
Developed by me using BMC CDA
Lotus Elise, stage 3 head (gas flowed with bigger valves) 4-2-1 manifold, larini exhaust
Pipercross viper (developed with lotus for the 340 R)
Moved on the the ITG Maxogen (carbon fibre..mmmmmm)
Now these systems are properly developed considering the air flow using ram pipes, veins etc to cause turbulence/accelerate etc the air flow to the engine, not just a change in fabric and making the hole bigger