The only things i have done to my Z is flowmaster exhaust moroso cold air induction underdrive pulleys and ported maf sensor. Well and a set of 18 inch wheels. It runs pretty strong and I have big plans and money to do it also. About the zx-7r this bike is certainly one of the worst performing bikes out there right now and yeah the katana is right beside it. I have a 900rr and that was my first bike about 3 years ago. I took it to the track several times and flat out smoked zx-7s and i was running high 10s well 10.60s to be exact. If this is your first bike it might be cool but youll wish it were bigger after a few months you can bet on that.I would seriously rethink that decision.