I just installed my T78 w/ the orange (low boost) spring and I conencted the side port of the wastegate to the manifold pressure and left the top one open. It runs about 10psi w/ the low spring. I think you can tighten the screw on top to increase the boost off the wastegate. The car feels pretty damn slow at 10psi though
that should be the lowest possible boost you can achieve with that spring....I ordered my spring about a month ago...Greddy is supposedly back ordered on this part! Hopefully it will be in today...cant wait to make a full pull at a whopping 1.1 bar!