Progressive Lowering Springs | Cobra suspension

Progressive Springs

Cobra Suspension uses the manufacturer's original design as our reference design. In most cases, the original springs of a modern car already have a progressive effect. We optimize this design even further when lowering a car. In some cases, we choose to give a spring two spring rates, a so-called 'dual-rate'. These are actually two linear springs with different spring rates in one spring, which, in addition to the original progressive effect of the original spring, work separately from each other.

What is progressive?

With a fully progressive spring, the spring rate increases with further compression. So for every next millimeter of compression you have to apply more force than for the previous millimeter. With coil springs, this can be done by making the spring non-linear. Non-linear coil springs are made by varying the pitch (the space between the coils) of the coils or by applying spring steel in a varying thickness. At Cobra Suspension we produce both progressive and linear springs. The two left springs in the picture have a variable pitch (progressive). The two right springs have a linear pitch (non-progressive).

Dual Rate Springs

Cobra Suspension lowering springs apply, if required, a dual rate design, combined with the progressive character of the OE spring. The graph shows the force versus the length of a spring. With these graphs we can also determine the spring rate of a spring. There you can see that at a spring length of 195 millimeters the springs switches to a higher spring rate, the graph becomes more steep. Up to 195mm the spring has a lower spring rate. After 195mm, the spring rate becomes higher. This point varies per spring and per application.

Minimum Length

Lowering a vehicle can be done in several ways. This can be done by using a shorter spring, a lower spring rate, or by applying a dual rate spring. Making a spring shorter sounds logical, but the spring doesn't always have to be shorter than original. A spring can't be infinitely short either. A minimum spring length is needed to give enough pre-load between the shock absorbers bottom and top spring seat in unloaded condition. That is the distance between the top and the bottom of the shock absorber or chassis. The spring must not move between the spring seats and must therefore provide enough pre-load.

Lowering with Dual Rate

When lowering with a dual rate spring, the lower spring rate causes a number of coils to fully compress under load. This part no longer participates in absorbing bumps, while the second part of the spring becomes the part that is actually absorbing the bumps. When designing the spring, we take a close look at the original character of the car and consider all components that influences the design. The length is important because the spring should not be too short. Also, the spring should not be too soft, because this causes an annoying driving behaviour. The combination of these two design aspects means that in some cases we opt for a dual rate spring. This allows us to lower the car nicely, but also to apply a higher spring rate. The coils with a smaller pitch ensure that there is sufficient pre-load. The coils with a higher pitch provides an appropriate spring rate that makes the car drive well.

In summary

Cobra Suspension lowering springs are therefore always optimized for the right application and we always make a well-considered choice when designing the springs. A dual rate spring may look strange underneath the car, but the design of the spring has been designed by our team to give you the best of both worlds. This allows you to greatly improve the looks of your car without compromising on driving qualities.

So that's why!

• Lowering without using spring rates that are too soft
• Lowering without compromising on pretension
• Lowering without compromising on safety
• Lowering without shortening the spring too much
• Better handling characteristics
• OE-like comfort characteristics