Hello all . I may have posted this is the wrong bit, i wasnt too sure where to post it.

Well a while back i was looking at getting an escort RS Turbo. After having a look around ive got my eye on an st170 or a focus RS ( older shape )

Theres something like 50 bhp between them both and any where from around 4k plus price tag.

Now my question is could i get an ST170 then basically tune it or put one of these ST170 race engines thats ive seen and then supercharge / turbo charge it and it would be even quicker than the RS?

http://www.cncheads.co.uk/ford_st170.html - cylinder head for st170

and then could get the rest built up as ive seen a " race engine ".

OR

should i buy the RS then if i need more power just get it remapped or if im realy fussy a bigger turbo

I am looking around the 5 second mark without use of any nitrous is it too much to ask ?

Anyways what ya all think ? sorry for the silly question