composite rear springs

[raybies]

Any suggestions on the correct rear spring rate ?
These composite replacements come in a widely varying array of spring rates from like 340 lbs to 400 lbs \ in.
What would be the best for my 1980? I don't race it but I do drive it seriously meaning I want it firm flat and stuck to the road in corners.
Right now it has a tendancy to break out and when it does it breaks out hard.
All the components other than the Bilstein shocks are stock at the moment.
Any suggestions I would be grateful for.
Thanks

 

[JohnZ]

I want it firm flat and stuck to the road in corners.
Right now it has a tendancy to break out and when it does it breaks out hard.
Thanks

If by "breaks out" you mean it oversteers (breaks loose at the rear), increased rear roll stiffness will just make that worse. Stick with the lower load rate for the rear spring. You MUST have rear shocks valved specifically for the composite spring application (higher rebound damping), or the "bouncy-bouncy" syndrome will drive you nuts; composite springs have no interleaf friction like steel springs do, so increased rebound damping is essential.

 

[6880 Mike]

Any suggestions on the correct rear spring rate ?...
What would be the best for my 1980?...

You could consider the stock fiberglass springs installed under the 81 and 82 automatic cars. Genuine GM.

I'm looking for a pair myself.