Is this a 1 bar spring ?
 

I have a spring for my wastegate for a 1979 930.

size:
19,5 cm = 7,6 inch long
0.5 cm = 0.2 inch coil thickness

no paint markings

Is this a 1 bar spring ?

nobody got a 1 bar spring laying around who can measure it for me ?

924ttturbo, check out this thread of mine about 1bar springs...

http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/396307-boost-springs.html

Springs in from the wild are real black magic to try and figure out what they are.
My advice, just buy a new one so you can be sure!

924ttturbo, I'm sorry that I can help you directly, as I'm working from a different part of the country from where my car's located.. But the 0.8Bar spring is about bronze colour and about the size of a pack of McVities Digestive biscuits; the 1.0Bar spring is silver coloured and about 2/3 the size.

From the dimensions alone, the spring (if it's from a 930 or 964 turbo) sounds to be 0.8Bar.