My Fiesta ST

[subxero]

Hmm let me think of Fords other ST 2.0 litre lump.

Oh yeah the ST170 in the Focus made before the ST150. So they did detune it, probably for product range reasons and then no doubt the normal emissions rubbish.

Dont even know if its a similar engine etc but seems inverse Nova maths is getting pretty prominent on forums.

Nope, different engine. The ST 2.0 out of the Mk1 Focus was a VVT engine, whereas the Fiesta ST engine is basically a rebadged Mondeo engine (Duratec ST) that has been slightly tuned to add an extra 10 - 15 bhp iirc