Mark RS,

Thanks very much for the reply.
I see what you mean

So once the actuator alone is set to say 12psi (standard 4x4) and the Amal Valve reconnected the boost will drop, then its a case of reducing the Amal Valve jet (is this the one to the airbox???) until the boost pressure is back upto 12psi...???
Is that right?

Cheers