[ubrben]

Originally Posted by phoenix

There are a couple of things about your proposed setup that would worry me.

For the helper spring to become coilbound after a total of 1" compression, the total clearance between the working coils of the 1000lb spring at static ride height would need to be 4.23mm. This is a very small gap spread amongst however many working coils you would have, and I would be concerned that
getting such precision in the spring manufacture might be difficult if not impossible. The left and right hand springs would need to be identical, and not just millimetre perfect but maybe 0.1mm perfect, because if the left and right hand springs were different you might get odd handling under braking, for example.

The increase in stiffness in your setup would be like a switch - one moment 167lbs and an instant later 200lb. I wouldn't think the 20% increase would be a problem in itself, but if the setup between the front and the rear of the car is different - as it will almost certainly be - then the end that suddenly gets stiffer first will immediately carry more load. If this happens at the front, then you may get sudden understeer; if it happens at the rear, then you could get instant oversteer.

I would imagine it would be very difficult to get the transition points for the front and rear springs perfectly matched for all significant circumstances - i.e. turning into a corner, mid corner and accelerating out of a corner. One end is almost certain to get stiffer before the other.

Anti-roll bars do at least offer a more progressive solution than dual rate springs.

Why not just use bump rubbers and packers?

Ben