amal valve + in car switch is easy enough. nothing wrong with bleed valves except the temptation to meddle causes meltdown and there a bit crude. for x2 stage boost you need a nice toggle switch, some apt wire and connectors (x4) 2 male 2 female. cut the negative side that goe to amal and join the switch in line. the switch will operate the amal so if the switch is not active the actuator dictates boost. if the switch is active (amal on) the amal bleeds off giving more boost. you can also set up the amal to give desired boost using inserts. i used a coupling in the hose to give the reguired boost level rather than nylon inserts as i couldnt find any. its an hours work and much safer than a bleed valve.