Spring rate for rear coilovers

[evilC]

The helper springs are there essentially to retain the main spring against the spring seat particularly where the main spring is stiff and has limited travel. Also the helper spring adds an element of dual rate and on the road softens the initial take up for both comfort and to get the damper moving so as not to rely on its high frequency/short stroke characteristics that seem to go off so quickly on all dampers.
The smallest common helper spring is 50lb/in that on the rates quoted above would be significant (~ 50% main rate) on the front and noticeable on the rear (16%-40% main rate). For the front I would consider them as an initial comfort setting, whereas on the rear the helper spring will lock up more quickly to handling advantage. Also, because of the light weight they will allow greater suspension travel before lock-up making the front seem initially too soft and uncontrollable on a comp car. In summary I thing helpers would be worthwhile front and rear on a daily driver/occasional comp car but only on the rear for a more focused comp car.

Thats my sixpenny worth and I would be keen to hear further thoughts.

Clive