Basically you take a part and make it stronger. It does not necessarily mean that the part in the world now is not good. For example you can say stock rods from any car work very well until someone like me wants 3x the horsepower. So rods are machined to be stronger and lighter. Now anyone can do the rod thing so I'm looking for something else that might be more fun.
Some other examples are:
Shift forks re-design on my civic (they break alot with high horsepower)
Lower Control Arm design, strengthen and lighten
Here is a link to one someone else did a few semesters ago...
New Page 2 New Page 2 New Page 2 FINAL REPORT
Some of those aren't making things "better" but I would like to learn something from this. Maybe make a part that someone might want to use. That and I want something cool to prototype.