do i have up-grade to bigger brake calipers(front) when i swap to my 17's or is all that optional? i would like to keep my factory brake calipers just in case i have to sawp back to 14's one day.
Since the rolling mass of a 17" wheel and tire is likely greater than a 14" wheel and tire, I would say yes, you should upgrade your brakes, but I'm sure lots of people have done it without upgrading.
i didnt upgrade the fronts when i went to 17s and my car stops like it did before... however i only went to 17s to make room for cobra brakes later