Corvair.
My original turbo car, back in 1979-80 used a modified Corvair turbo. I tried using the distributer vacuum advance hooked up to manifold vacuum, and adjusted the curve accordingly. It wasn't very good. Wound up using a MSD "ping control". Better, but not as good as a "boost timing master" (which wasn't on the market then). Also did not have AFM meters back then. Tuning was a *****. None of the turbo companies would give out any info either. Propriety info, don't you know? Broke some parts but kept learning and improving. Was able to drive to the track put on the slicks and run lower 13's at about 104 mph. 170 engine, about 2800-2900 lbs
PS: Still have that car and engine. Engine is out for freshening up.