Base case specifications :

The springs will be matched with adjustable Koni sport shocks in the front. I already have Tokico rear shocks in good shape in the rear of the car. I�ll keep them. The damping of the Tokico beeing not adjustable and tuned for after market lowering spring, the spring rate must be kept in the 150-160lbs/in in the rear. The front will have to match even if the Koni can be adjusted for spring up to 300lbs/in.

Fearing too much oversteer from Case 1 and 3, Case 2 is selected.

 Selecting a spring length

 Coilover springs are available in 10 and 12in length. Calculated static deflection is 4in. but installation shows a 3.5in static deflection. Car is weigth must be overestimated or unsprung weigth under estimated.

 10in-175lb/in Afco made spring have a maximum stroke of 6.3in before coilbind. Since static deflection is 3.5in, only 2.8in of suspension travel is left before coilbind. The suspension bottom must be a rubber bumpstop. It must not be coilbind. If coils bind, spring seats may break or strut tower may rip. Shocks must not bottoms either. Thus a 10in-175lb/in spring in the front requires a least a 1in drop in ride height to prevent coilbind.

 A 12in-175lb/in springs in the front allow the car to have its normal ride height without coilbind but the maximum drop is about 1in.

 At the rear, the problem is similar. 10in-150 lbs/in springs require at least a 1in drop to prevent spring bind. 12in-150 lbs/in springs is correct the maximum drop is 1inch.

 Usual spring rate are in increment of 25lbs/in. But Afco also offer a 12in-160lbs/in spring. The final spring choice is 12in-175lb/in springs for the front and 12in-160lb/in springs at the rear.

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