Spring rate help?

MaysEffect

Bringing this topic out of the dead based on conflicting priorities around the same time as this. For whatever reason this thread isn't stickied, but a topic about "coilovers kits" IS. CIRCA 2013-2015

I recently made a post in this thread -What to look for and WHY: Coilovers
On how people were putting way too much emphasis on damper quality and features oppose to making sure the springs were adequately matched for the potential weight of a vehicle and its subsequent loads with gravitational forces, tire traction and other variables. As i didn't include a detailed response on what and why, the information here should answer most, if not all discussions about springs that i would have attempted to make all over. IF POSSIBLE THIS THREAD SHOULD BE STICKIED.


I also read somewhere a few pages back (a few years back lol), the OP asked if he would need to change the free length of the spring if he was to go up in spring rates. I'm not entirely sure the question was answered, but in short i would say it would be dependent on the suspension travel needed to be achieved and the potential load a tire will see under g-forces.

The length of the spring is dependent on several variables.
A few of which being
- total suspension travel achievable given the space around the tire from static ride height
- length of the damper and its available stroke until bumpstop is engaged
- Weight needed to achieve optimal preload and the springs overall compression length before binding
- springs load capacity before binding (at best should be equal to or greater than the total corner weight the car can realistically achieve)

In a fictitious situation where you only want/need to achieve 2.5 inches of spring travel from static ride height > while also falling within the load capacity of the potential corner weight> And you can achieve this with a 5 inch spring. Suppose the question now is, the spring mounting length needs a minimum 7 inches or the car will bottom out, engage the bumpstop, or unseat the spring? This is where a secondary spring can help. Of course there are several instances and variables that would require the use of a helper/tender or secondary spring. But at the very least, this is what it could be used for.

Beyond this, there's a completely bigger rabbit hole to go down, i merely wanted to equate the differences between the information here about spring tension vs the argument about which coilover kit is best for "said" driving style.

Great information here.