Well, the vacuum advance is the last thing you need. With a turbo you'll need the exact opposite. You have to retard the timing as boost inclines. That's why Im going to find a programmable ignition system
Here's some information, maybe you can use some of it, but maybe not... it may not be applicable for your system:
My turbocharged 225 engine has a distributor with no vacuum advance diaphragm and a locked plate (NO centrifugal mechanism; it's out of a Lean Burn motor.)
No advance of any kind.
I set the advance at 18 degrees.
It starts with no kickback and drives out beautifully; no problems. No run-on when I turn it off.
BUT, it gets UNBELIVEABLY BAD gas mileage on the street... I am amazed that you can actually PUT that much gas through a 650 Holley. Believe it!!!!
It NEEDS a vacuum advance unit, for gas mileage.
Since this is a race-only application; no street driving, it will never get one, but the actual drivability is good and it idles nicely at 500 rpm. No "curve" required...