The simplest way to find out if you have vacuum or mechanical secondarys is to get a mate to put his foot flat on the throttle ( with out the engine running) and look down the throats in the carby if both butterflys are open you have mechanical and if only one butterfly is open you have vacuum secondarys.

the fuel set up I am running is set up to have a set pressure of 5 psi and when manifold pressure goes above 5 psi the fuel pressure goes straight up to 14 psi.I set it up like this because I was on a budget but it works for the best because on boost it floods the carby (sort of) which works out well.
On the drag strip you can see just a faint puff of black smoke of the start line. Mind you the poor thing is leaves the line at 5000 revs. The motor I am running is totally standard and cops a floggin, It has done 22 runs down the quarter mile in two meets, and Ive only poped one head gasket and one standard diff, and Im gettin 15.2. I even beat a GTR skyline up to 60ft mark. then it mowed me

The box has a thread on the side of it and a bolt is screwed into this thread which hooks up to the butterfly inside the box and then the linkage is hooked up to the bolt on the out side. Ive got a pic of it but it is not real clear I will put it in the forum under "turbo carby" but tomorow Ill get a better one

I ran a BOV woth my set up but It gave me the s hits and proved nothing much so I took it out and the turbo's are still alive now

and a nother way to keep the turbo on boost between changes is not to take your hoof of the exagerator. just flat change it.
Its a bit harsh but its fun