Originally Posted by
Sp3no
The dampening rates on the rear dampers may be different so fit your rear shocks in place of the ST170 ones till you get a set. The rear springs will be 15mm lower than yours also. Get the eibach springs for definate, i have them fitted to my ST170.
Not quite........
The dampers on the ST170 are EXACTLY the same as the Zetec 'sports' ones (approx 15-20% stiffer than the CL/LX/Ghia ones) so - as you have a 3 door you must have a Zetec trim level - meaning the dampers will be exactly the same as you already have.
ST170 springs are 20mm lower than the rest of the range and marginally stiffer as a result, up to you if you go for Eibachs or not all round the car, a common criticism is that the back end of a Focus sits too high compared to the front anyway so you may well fit them and find it gives a better, more level stance!
See how you get on, you're certainly not going to do any damage or fuck anything up by doing a straight swap and upgrading/changing bits as you see fit. Your standard handbrake cable and brake lines will just about fit as well though the brake lines will be a slight stretch to the new calipers. I did a drum -> 2.0 litre disc conversion on my 1.8 so changed brake lines and handbrake cable to do this and then later upgraded to ST170 discs without having to change anything else.