you can change the gizzmos from closed to open...at least mine you can.
you can't change them, the newer gizzmo controller is close loop (i think),
the older one open. actually you can probably change a closed loop one to
open, but not the other way around. closed loop means there's a feedback
loop which the controller uses to make adjustments to the wastegate duty cycle...
in the case of the original gizzmo device and the greddy profec b, there is no
feedback loop. The person doing the tuning is the feedback loop in effect, and
once the parameters are set, there's no logic within the device to make further
adjustments.
A good controller IMO would be one where you just plug it in, and tell it how
much boost you want, and it just does it, and it maximizes boost throughout
the rev range and in every gear... no telling it how much to open the
wastegate, or any other crap, it just figures it out. At a guess this would make tuning
difficult, because the boost controller might be constantly adjusting things.
