Hello friends, I own a focus mk1 1.6 gasoline from 2003, has made the following improvements: exhaust manifold 4-1 stainless, exhaust line, MSD coil, MSD cables, spark plugs, and pipercross filter. I turn to your wisdom to know what I can do more, to gain power (accelerator body, intake manifold etc etc). many thanks.

 

Have a look at a firm called Shawspeed.

You are looking at the standard route of throttle bodies, stand alone management, cams and head work along with a few supporting mods like rod bolts and a proper exhaust.

You are wasting your time with the mods you have described.

No replacement for displacement, get a bigger engine ie st170.