Interesting discussion here.
On topic: Unichip - meh. As others have said look at a Power FC instead. I don't like the idea of 'tricking' the stock
ecu into thinking its doing something its not. Regardless of how good the tune is, it just doesn't seem right. But thats just me.
Now for the open/closed loop discussion...
My brief understanding:
Open loop system: No feedback is involved. Pre-programmed maps are run without checking any meaured variables.
Closed loop system: Feedback is put back into the controller from measured variables.
Easiest analogy (had to use a word with 'anal' in it) is an airconditioning system. If you just turn it on, cold air comes out. No check to see if the air is too cold, if the room is too cold or you are frozen. Open loop system.
A climate control air conditioning system gets feedback from different variables to hold the temperature of the room at a specified temperature. Closed loop system.
Now as for the
ECU's... From my brief understanding the
ECU has a target map for boost, which it tries to achieve. Now to achieve this it has to be reading variables so it can correct the boost to arrive at its target. To me this sounds like a closed loop PID controller.