The best way to Set Correct Spring Pre Load on Coilovers

So you have bought a set of coilover shocks to your automotive with spring pre load (or “spring rigidity”) adjustment, however are you aware learn how to correctly set it? Possibly your coilover system doesn’t have impartial journey top adjustability, you set it to yield a desired journey top, and are actually simply hoping the set pre load is inside correct vary. Or perhaps your coilovers do have spring pre load adjustability impartial of journey top adjustability, however you’re not sure of how this impacts efficiency. On this article we are going to describe the results of spring pre load and learn how to correctly set it.

Having an excessive amount of or too little spring rigidity will negatively have an effect on suspension efficiency, however in numerous methods. An excessive amount of spring rigidity could make your suspension really feel like it’s topping out. This occurs as a result of now the shock extends to its most size too abruptly, and this will unload your wheels from the street floor. Not sufficient spring rigidity could make your suspension backside out excessively. Realizing these results might help make the right changes.

Let’s outline a number of phrases to assist perceive spring pre load results. The quantity of stroke the spring consumes at static journey top from the load of the automobile is known as “droop.” And the quantity of stroke left over at static journey top is known as “compression stroke.” The full shock stroke is droop and compression stroke mixed.


Whole Shock Stroke = Droop + Compression Stroke

It is very important perceive that spring rigidity doesn’t have an effect on the spring charge of a linear spring (most coilover methods include linear springs). For instance, growing spring pre load WILL NOT enhance the firmness of your linear spring. Nevertheless, this WILL enhance the quantity of compression stroke you could have which will increase bottoming resistance.

Springs on most coilover methods need to be pre loaded in an effort to retain a fascinating quantity of compression stroke at static journey top. For instance; when you’ve got a coilover with a 200 lbs/in spring charge carrying 800 lbs of weight, with none pre set spring pre load, the coilover will compress four” simply from the static 800 lbs of weight appearing on it. If this coilover has a complete of 5″ of stroke, this solely leaves you with 1″ of compression stroke left over! On this state of affairs you will need to pre load the spring to insure you could have greater than 1″ of compression stroke. There’s manner an excessive amount of droop on this state of affairs.

So we now know that spring rigidity impacts droop. However what’s the correct quantity of droop to have? This varies relying on how a lot complete stroke your coilovers have, so we deal with the specified droop as a ratio of complete shock stroke. With a view to have an applicable quantity of droop, we advocate setting droop to be 30-40% of the full shock stroke (see equation beneath). Now you realize that it’s a must to modify the spring rigidity in your coilovers to yield 30-40% droop!


Desired Droop = Whole Shock Stroke x.35

The best way to set spring pre load:

You have to first measure the full shock stroke of your coilover (together with the bump cease size). Then measure how a lot the coilover compresses when the automobile is at static journey top. Subtract the compression stroke at static journey top from the full shock stroke to search out the droop quantity. Alter spring pre load till suspension droop is between 30-40% of complete shock stroke.


Droop = Whole Shock Stroke – Compression Stroke

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