dont want to be a kill joy but the intercooler from radtec for the focus ST is even bigger than this one, anysize intercooler will not give you 1bhp extra, just help keep temps down, in not so sunny england a 3inch downpipe will give a real power gain forget a catback (sounds better) but does nothing or a 100cell sportcat which keeps your dashboard iluminated. ED30 ecu upgrade 3" turbo downpipe is the way to go.