jonathan, I've seen the English language marred pretty badly, but man, that's really pushing it. haha
Your car is getting 13.8-14.4V, and chances are you can't change it because the voltage regulator is inside your alt. Why would you want 17V? Some amps and headunits won't even power up with that many volts.
Simply put...don't worry about it, you're only going to mess things up lol
the only time u want 17 volts is if u are into comps (which by your questio i dont think you should cause u dont know anything lol) but ya like running a dd z1 for ex they run on 17 volts to make them run cleaner but then again that is basically for comps