I am going to say it......squeezing any kind of insane power out of Contour will be pointless.
Say you do make 500 hp on you Zetec. Which will require around 30 psi. Engine right away, even built up, is going to liability. The car doesn't hook up, so you have to put slicks or drag radials. You start breaking driveshafts. It would go on and on...
Unless you have ALOT of disposable income doing all of this....
With all that being said....I would love to see someone do this. Not 500 HP but a 300-350 HP turbo Zetec.
It would be reliable, wouldn't have to run too much boost, and more than likely would be faster than a Duratec Contour with the same power.