At what point should you start upgrading your fuel system, i.e. high flow injectors and fuel rail? Should you do basic upgrades like intake/header/exhaust first, or do you even need high fuel flow until you get into the advanced stages of a build?

 

Yeah, I wouldn't bother with the fuel system unless you do something serious like big ol' turbo with some serious boost or bore and stroke you engine significantly. Otherwise you are just wasting money and your car could actually run worse. The stock system is perfectly capable to deliver what you need if you only have bolt ons.