The Yenko Stinger Vega and Stinger Turbo is an interesting story and was ahead of it's time in some ways but the design problems of the Vega engine resulted in a failed attempt by Yenko to complete his plans.
From what I remember......
He tried to build a SCCA Competition Vega and a Turbo Vega street car.
He did build them both but had problems with both and had hi po Vega parts in his catalog
The Rajay turbo was only used on the prototype
It proved to be too expensive because it required a special carburetor
Yenko changed to a Schwitzer Turbo that used the stock carb and came in a kit package
Yenko built a SCCA Vega race car and brought it to Daytona but it failed to qualify due to engine problems
Yenko built some Turbo Stingers and tried to get them EPA certified but they failed.
Some were tested by car magazines and the turbo kit was offered in the Yenko parts catolog
If you search around here, there is some info on this site that has been posted over the years
also some info here
http://copo.com/yenko-stinger-vegas.html