Originally Posted by bluescoobywagon
Taking this one step further, if the internal wastegate is controlled by an interupt as per your diagram, couldn't you set the max duty at 100 with a target boost that was really high at 100% throttle? That should create the following scenario:
Target boost at 18psi and WGDC normal in 85% throttle column.
Target boost at 21 psi and WGDC at 100% in 86% throttle and up column.
MBC at 19psi.
Boost below 19 psi would be controlled by the internal wastegate only.
At above 85% throttle, the target boost will jump up and drive the WGDC to 100% closing the internal gate. Boost is now controlled by the external gate only.
I haven't tested this as I don't have an external gate yet, but the theory seems sound. You could set the crossover point for whatever boost and throttle % you want. Personally I would change the 100% throttle column to a value close to the crossover (like 86% above.) That way you would have a clear switchover point and then adjust it as needed for a smooth transition.
You just explained how this already works!