John Kelley asked: "And WHAT associations would that be ???? "
One such association is the "National Auto Sport Assn." (NASA)
For a discussion of that ruling, check out
http://tinyurl.com/62uvxs[/
There is another racing series that is exclusively Subaru turbocharged cars that also has
mandatory telltale boost gauges, but I can't remember what that series is called. But, both
organizations require them.
Why do you ask?