Ford discontinued the SVT Specific Tensioner for our beloved and high revving Focuses. The difference in the SVT version and the garden variety Zetec version is the spring tension. Cosworth Engineering specced the SVT tensioner with 2lbs of tension, double that of the ordinary Focus. We do rev an additional 700 RPM but more importantly with our VCT the intake cam can move up to 35 degrees so it's not hard to picture the havoc for belt tension. It all happens fast but I picture the cam almost stopping for a millisecond when it's time to retard the timing, allowing the belt to freewheel past until the required degrees are dialed and then it grabs some tension again to continued the ride.
Anyway, for the true DIY er here is just the spring that you can change out if you have a regular OEM Zetec tensioner or one from the OEM supplier Litens (Continental versions are marked as such). Never tested or tried or intended for use on the Gates style (they don't look the same externally and I haven't disassembled any).
I ALSO HAVE A limited number of Tensioners that I have changed the springs in already along with some complete kits - Belt, tensioner w/spring and idler pulley - check my other auctions
Matt Rowe
5 Acre Focus