By keeping the wastegate in a closed position more often, a boost controller causes more of the exhaust gas to be routed through the turbocharger, thus reducing [[Turbocharger#Turbocharger_lag|turbo lag]] and lowering the [[Boost (automotive engineering)#Boost threshold|boost threshold]].{{citation needed}} A boost controller also reduces the need for a stiffer spring to be used in the wastegate.{{citation needed|reason=References are needed to show what benefits this results in.}}
Since less positive pressure can be present at the wastegate actuator as desired boost is approached the wastegate remains closer to a completely closed state. This keeps exhaust gas routed through the turbine and increases energy transferred to the wheels of the turbocharger. Once desired boost is reached, closed loop based systems react by allowing more air pressure to reach the wastegate actuator to stop the further increase in air pressure so desired boost levels are maintained. This reduces turbocharger lag and lowers [[Boost (automotive engineering)#Boost threshold|boost threshold]]. Boost pressure builds faster when the throttle is depressed quickly and allows boost pressure to build at lower engine RPM than without such a system.
This also allows the use of a much softer spring in the actuator. For instance, a {{convert|7|psi|bar|abbr=on}} spring together with a boost controller may still be able to achieve a maximum boost level of well over {{convert|15|psi|bar|abbr=on}}. The [[electronic control unit]] can be programmed to control {{convert|7|psi|bar|abbr=on}} psi at half throttle, {{convert|12|psi|bar|abbr=on}} at 3/4 throttle, and {{convert|15|psi|bar|abbr=on}} at full throttle, or whatever levels the programmer or designer of the control unit intends. This partial throttle control greatly increases driver control over the engine and vehicle.
