How are you going to map ignition?

with regards to fuelling though, wideband gets you to where you *think* the car wants to be, ie "I reckon 11.5:1 at 2 bar of boost is a good starting point"
Ideally though, you would then look at EGT's as well, like for example Stu was saying Focus RS need to be a lot richer than a cossie in the same circumstance, so you need to be monitoring other things to know that.