First, boost is boost, it doesn't matter what engine, or what compression it is. Lower compression is a good idea for either turbo or SC, but that's a whole nother can of works.
I can't speak for other engines, but when it comes to the Zetec a supercharger just can't compete with a turbo, period.
Let's look at a few charts.
Here's a Vortech on a regular Zetec at 9psi with several mods:
Here's my TQ chart, 211wtq at 9psi, stock block and full 3" exhaust(the blue line is with a 35shot)
Here's a stock Zetec with Turbo Tom's kit at 8psi:
Here's a SVT with Tom's kit at most 8-9psi, not sure which.
Here's a custom SVT turbo kit at 6&10psi
Here's Jackson Racing's kit at, I belive, 6psi:
Here's a Vortech SVT chart at 9psi:
That's a mustang dyno and the guy says it's lower than it'd be on a dyno jet. He posed anotehr chart where he reved to 7600rpms(stock redline is 7250) here:
http://www.dfwstangs.com/hosting/Saleen09/resized_dyno_1103.jpg You may have to cut and paste the link, cause it doesn't let you view the image inline. That's actually fairly respectible, but I don't like the fact that he's reving past the stock redline. For ease of engine internals, you shouldn't rev past the stock redline on boost on the stock block.
Now the SVT will respond better to boost since it has a better flowing head and intake, but the higher compression means you won't make much more HP than a totally stock Zetec since you'll have to pull more timing on the SVT. You will never convince me that a SC is better than a Turbo on the Zetec, but if you have to go SC, go with the Vortech. It will give you more HP and TQ than the JR, though it's a more involved install than the JR.
I am currently beating every Supercharger kit for any Zetec,except the SVT Vortech kit at HP and TQ. I am beating the SVT Vortech kit at TQ, but again, the SVT head and intake flows better and has a higher redline, so it will make more HP. Tom's turbo kit at
www.focus-power.com, is the only proven turbo kit for either regular or SVT Zetecs, and it beats both stock JR or Vortech numbers, expecially TQ, though it makes no more HP than the stock Zetec turbo kit.
Let me just state this one more time for the cheap seats. Buying a brand new SVT engine to do a swap then to supercharge or turbo it is a WASTE of MONEY since you can't squease out more HP on the SVT with FI than on a regular Zetec since the higher compression on the SVT limits the boost and timing you can run. Your best bet is to add forged internals to the stock Zetec then do a Vortech or Turbo Tom turbo install. Tom also sells the Vortech at a good price and his tuning is second to none.
IF, you could get a slightly used SVT engine and wiring harness and ECU for around $1000, then I think it could be doable. But if you're buying brand new, it's not worth it.
