I fitted the complete Spyder supplied Sierra brake system (and wheels ) with Willwood 4 pot calipers to my non-Zetec Plus 2S a few years ago. I still have the standard +2 servo (3:1) and a 3/4" master cylinder.
I still need to be fairly hard on the pedal for maximum brake effect.
(I don't know what servo (if any ) Spyder fit to the Zetec, does anyone have details ? )
I have considered fitting a dual brake system, I understand there is a Triumph dual M/C, but I fear two servos might be required.
I put the car up on blocks last evening to do a thorough brake bleed, as the pedal feels a bit soft