Originally Posted by
Skiddins
Trouble is spring rates are not constant, they are rated as such for ease of use but it is easier to move a spring the first 5mm of travel than it is the last 5mm. As the spring is compressed the tension builds.
You are mistaken. You are confusing the total amount of force exerted on a spring with the amount of force required to compress a spring a given amount.
Regardless of the preload on a spring, if I wish to compress it an additional 5mm it will always require the same amount of additional force to do that.
The only exceptions to this is where the spring is so compressed that coils are starting to touch, or where the loads on the spring are so far in excess of the capabilities of the spring material that the spring is failing.
I suggest you do some reading on Hooke's law, the spring constant and coil spring behaviour in general.
I always make sure my car is manually tweaked before running. If it is not it is easy to tell. Using corner scales is another way of acheiving the same result.