People have been overdriving superchargers for years. Every supercharger or "blower" I have ever heard of over the past couple decades has been able to handle an extra 3 or 4 psi without having any issues. The same goes for turbos, it is very common for people to buy boost controllers and throw them on their turbo cars to raise boost by a few psi.
People have been doing pulley swaps on Mini Coopers, the Cobalt SS, and the TRD supercharged Scion tC with good results over the past few years.
You guys who are interested in pulleys may want to check out this link
http://www.nonstoptuning.com/pageSponsoredTC.htm
They make some killer stuff
