I just did this nifty little mod on the weekend in my R33 GTS25t. Sweeeeeet.
Used the wire through the plug method as in post 231 page 12 and 571 page 29...
except I put a switch in my centre console where the snow/power switch was.
(Used to be Auto but was converted to manual in Japan).
I just use it for that ocassional extra kick in the pants.
Being pretty new to Skyline ownership, I find the extra little bit of boost is just fine for the moment.
I did read on another forum someone suggested using 2 stock boost solenoids might up the boost by an extra 2 psi. Would this work?