Not very many

The st170 engine is based on the US SVT zetec engine, and isnt a duratec no matter what it says on the engine! (dont let that rocker cover fool you!). Its the same as the Focus RS engine, which is based on the UK zetec lump with a few mods.

It would be pushing a lot more brake if it was a duratec engine (standard at 145bhp, zetec is 120bhp area)