Hi i was wondering how does a boost controller work and does it increase Hp?? thanks

 

A search on this would have probably gotten you some results, but if your impatient the answer follows below.

 

There are several forms, but they all work by reducing the boost pressure sent to the wastegate actuator. This fools the actuator into thinking the engine is producing less boost, so it holds the wastegate closed longer. If the wastegate opens later, more boost is pruduced. More boost means more power.
Electronic boost controllers do this with an electronically controlled solenoid valve, so they're more accurate and consistant.