Since we're talking about turbo boost gauges, etc. and what happens when the vacuum hose is not doing it's job, are the stock gauges that Saab puts into the instrument clusters actually calibrated in a way that makes sense?
it's fine to say 'dont take it into the red' but that means nothing to most people. 8-) When I've had the engine running in the 1983 8V turbo car I'm repairing, it's a bit confusing with the way the needle changes position depending on how much throttle the engine is given, etc. Once I get it roadworthy again (still needs tie-rod ends, ball joints and inner CV boots to be replaced first), I'll take it for a proper drive on the local road at a quiet time of the day to figure out what the turbo does (or doesn't do).
I guess it's one reason people fit boost gauges with properly calibrated scales.
Craig.