911 SC CIS pressure "adjusting value" vs "testing value"
 

I have the feeling that I'm going to feel stupid for asking this question ...

On the spec sheets regarding CIS system pressure, there are two number ranges given.

One is referred to as the "testing value" and the other range is referred to as the "adjusting value". Why two sets of ranges?

Is it as obvious as:

If you are testing, with your pressure gauge, the values ought to be between 4.5 and 5.2 bar (for a 81-83 SC).

And if you are actually trying to adjust the system pressure by adding/removing shims on the pressure regulator, you ought to get the system pressure into a range between 4.7 and 4.9 bar.

Basically, the operational range is fairly wide, but if you taking the time to tweak in the pressure, get it fairly centered in the operational range.

What I wrote makes sense to me, but I don't know if its true.

And if it is, maybe this post will help someone from embarrassing themselves with such an obvious question.

Thanks all!

That is the way it was explained to me by a technician and is the way that I use these specifications.

Rahl

Thanks for the confirmation,

Thurmond

My take is that Porsche is telling its dealer mechanics not to bother messing with adjustments (which carry some risk and are only stepwise adjustable since the little washers have a fixed width) if you are within the testing value. Not worth the time/cost versus what little benefit there might be.