also the escos one is not an amal vlave, it works completely different to the sierra ones.

the sierra ones just open at a level that the ecu says when the boost is too high.

the escos lectron valves use pulses from teh ecu to acyually control the boot level ( closed loop boost control) , this is normally only avaliable on P8 ecus, however i have noticed that teh RP labs L8 software now offers this