Two weeks? Heck, I spent all of last summer shooting myself in the foot by making too many "improvements" to my SC10. I cringe when I think about it, but I also learned a lot in the process and took lots of notes and recorded lots of lap time data. That's another key point, and really is the first step. Record your lap times, including standard deviations if available right away. Measuring where you are before you start tuning is the only way to tell if you are improving. Sometimes a car that feels faster really isn't.