i'm, only talking cossie yb here.

the chip has nothing to do with how much boost you run really, except for the function of the amal valve.

the boost is basically a function of the spring setting in the actuator, and the pre load on it. for example, a -31 actuator has a stronger spring than a std one, so it takes more boost pressure before the actuator rod starts moving. by shortening the actuator rod, you are compressing the spring inside and making more pre-load on it, again needing more boost pressure to move it.

the amal valve doesn't really do anything, except allow the ecu to cut the boost (ignoring the jets for a minute) in certain situations.

got to go now, top gear is on. maybe more to come tomorrow.