Do I NEED to have a booster controller to change the boost setting, or can a tuner change it through a reflash?

 

There are a number of options to control boost. You can have a manual,electronic,a 3 port boost solenoid, an open ECU tune with the boost dialed in. You can also run one of the boost control options listed above in conjunction with a open ecu tune and get great results. It all depends on what you are looking for. I highly recommend getting your car tuned if you are turning up the boost. Also remember that as you add mods your car will gradually boost a little more here and there. Hope this helps!

 

The car isn't really capable of reaching higher boost levels as-is from the factory. You can change the restrictor pill in the vac. line going to the BCS to give you some more headroom, but your best option IMO is a 3-port solenoid like the grimmspeed which can then be controlled through the ECU.