Just to clarify. I think Porsche numbers are for springs compressed to 191mm, not free lenght minus 191mm. Nm's on that 191mm absolute lenght should be what WSM say. Spring free lenght do not matter. 340mm is just FYI to help identify ok springs without compressing them to 191mm. I can be wrong but which ever is correct makes difference in calculations.

 

Errka,

I agree with your conclusion, that is how I interpret it as well. Unfortunately the WSM is less than clear on the subject.

Cheers!
Carl

 

Oh, that is interesting. I never read the WSM that way. It refers to length L1, but I never saw a diagram to indicate if L1 was the compressed length of the spring, or the length that the spring was compressed. If you are correct the OEM one-dot brown springs are more in the 245 to 250 lb per inch range according to the specs.

 

I have been looking for this information also and I have decided to try and measure the spring rate.
I have an old set laying around that may be for the rear. They have two yellow marks and the stamping number looks like H00 928 531 12 they are 418mm free length.

Are all the springs basically interchangable or to put it another way will they all fit on the same strut?
the reason I ask is, if i make up a jig will it be able to do other springs as long as the leangth can be adjusted?

Brian.

 

Okay I have determined that the spec L1 in the WSM is the compressed length of the spring.
I have measured my used rear springs an at the required compressed length of 253.5mm they are 4670 N which is low. If I try to compress them a distance of 253.5 they are way over the WSM spec of 4811 to 4910 N.