they do not make a chip for the S2.........yet - so, no help there - sorry
i did a bit of quick digging however, and autothority (probably the biggest chip maker and has been around forever) makes one that they claim 17hp and 16ft/lb with - their claims are probably accurate too, based on the fact that they claimed 11hp and 10ft/lb on their 968 chip, and that is EXACTLY what we saw on the dyno in multiple tests - it wasn't the best chip for the 968, but certainly seems to be decent for the 944 series
i found a link to their site:
http://www.autothority.com/products/ECU-Upgrades.html