When I started I just compared and tried to duplicate the yellow springs for a starting point ...

Resulting with getting as close as I could with the somebody's elses springs laying around in his pit box .

Then I drove & raced ..

refining the set-up now by judging how the car performs.

Not by how the car lands or feels on a table ....

Not saying your way is no good craig , just saying how I'm tuning ..

With Brown watching me try ...

BTW the red in question I believe is softer then the green , we had both around.
Was judging by feel & other's guessing as well ...