|
A twin spring setup can be designed as a main spring plus tender spring, a main spring plus a light spring, or two main springs.
The first example has a very light tender spring (which is fully collapsed at normal ride height) which just stops the main spring from coming off its perch (and not returning correctly) when the car is jacked up.
The second example has two different rate springs where the lighter spring is not fully collapsed at normal ride height but can be tuned to collapse with a small compression and brings the second (heavy rate) spring fully into play.
The third option uses two different rate springs (neither fully collapse) which can give a variable spring rate (usually progressive).
You can get a single spring which has a variable rate. These have one spring rate at one position (ie 200 lb to compress 1 inch) and another rate at a different more compressed position (ie 300 lb to compress 1 inch).
A single linear rate spring has the same rate right through its range (from fully extended to fully compressed.
A variable spring rate (whether 2 springs or one) allows you to have a 'soft' spring for traction out of corners and a 'heavy' spring to handle bumps. A linear spring does not allow this compromise which affects lap time and/or tyre life.
I hope that explains the difference and how it impacts.
|