So I wanted to create somthign that would let me switch between Low Boost and High Boost whenever I wanted. Someone posted about doing something with a MBC and Wastegate Boost... But honestly, wastegate was lower than what I wanted for my Low Boost setting, I wanted to be able to switch between my MBC and the Stock Boost Controller.
So here is a diagram of what I created.

The Solenoids are from a 1st Gen Legacy. You can get them from a JY, it takes on 12mm bolt to get them off, they are mounted right below the passenger side intake runner and hookup to the Charcoal Canister... I believe they are called Canister Purge Solenoids.
I had created the Diagram awhile ago, then i built it 3 days ago and have been using it around town...
ITS AMAZING!! I love it... getting about 23 mpg on Low Boost. And killing Hondas on High!
So the Low Boost Setting I'm running 8.7psi
And on the High Boost Setting it runs at 16psi
The only warning for anyone wanting to do this... If you accidently leave the switch in the middle, off position... You will have NO boost controller connected to the Wastegate.
So make sure that you dont do that and your good!
What I'm going to do is put two lights on the dash above the center vents, one Yellow/Orange for Low Boost and one Green for High Boost. That way you know if it isnt sending proper signal to the Solenoids.