What are Coilovers?
Coilovers are a more versatile adaptation of the basic car suspension. They feature a more durable design with the ability to adjust different parameters. Height and adjustment of load absorption/transfer are the two most desired features. Since these options are not usually found on factory produced vehicles, the aftermarket industry has filled the void with many choices. The Coilover-Store is here to help you make an educated decision as to which brand and which model will most likely meet your needs.
Getting to Know Coilovers and its Parts
Pillow ball shock top mounts are solid metal top mounts that take the place of the soft rubber insulated top mounts of your stock suspension. Car manufacturers use rubber top mounts in order to dampen road feedback from variable driving surfaces for a smooth feel. By replacing the OEM top mounts with pillow ball top mounts you are delivered a more precise, solid feedback of the road. More street friendly coilover setups such as KW Suspension V1, V2, and V3 options normally do not come with pillow ball top mounts and instead use the OEM top hats. This design is for street use with occasional track use, and are suppose to retain the comfort of a street suspension with the ability to adjust ride height, and shock dampening. Most coilovers and all racing coilovers come complete with pillow ball mounts for increased rigidity that will increase maximum road feedback and reliability.
Depending on vehicle application, some top mounts contain camber adjustment plates for camber adjustment offered by many brands including Tein coilovers, Ksport, and STANCE USA. Loosening the hex key bolts and sliding the camber plates for positive or negative camber can adjust these camber plates to your desired degree of camber. Positive camber will wear the outer edge of the tire quickly, and negative camber will wear the inside of the tire prematurely as well, so make sure you have a professional alignment every time you adjust your coilover suspension.
Depending on what type of coilover you are using there can be a variable number of damper adjustment dials for dampening/compression and rebound, usually ranging from 1 to 3 dials. The shock stiffness can be adjusted by turning the shock damper adjustment dial clock wise to increase the damper stiffness, and counter-clockwise to decrease the damper stiffness. Adjustment for driving/racing should be done with small increments and at a good starting point like full soft or full stiff. Then increase or decrease the setting according to behaviors of the vehicle. More details can be found here Compression and Rebound Adjustment
Coilover shocks can come in a variety of levels of adjustment on the dial, including 15-way adjustable with STANCE coilovers,30-way adjustable BC Racing coilovers, and infinitely adjustable KONI systems. For 15-way adjustment, you have 15 “clicks” to play with for stiffness settings. With the infinite KONI system, this means is that there are no clicks, and that you would simply twist the knobs to set the damper properly to your needs, or on certain applications, the shock itself. All this means is that you may still have the same level of full stiff or full soft as other systems like BC Racing 30-way adjustable coilovers, but adjustment is not limited to clicks. In most cases two full revolutions clock wise will yield the full stiff setting on the damper or maximum compression and rebound settings. Whereas going two full revolutions counter clock wise will bring the shock to its soft, minimum compression and rebound setting.
Spring rates define the weight rating or strength of the spring compression rate. There are typically two types of springs found in the automotive industry, progressive or linear. Factory springs are usually progressive springs, and very soft in comparison to linear springs. They are coupled with softer shocks to deliver a more street civil ride quality while still being able to deliver decent performance once they are compressed during spirited driving. Linear springs are just that, linear. They are more predictable, and deliver more direct feedback of the road while driving by eliminating the progression of soft to hard. Once you swap your vehicle’s OEM suspension to coilovers with linear springs, the spring rates are normally increased to deliver higher response during cornering, braking, and acceleration.
Picking the proper rate of spring is important. A light weight car such as a Mazda Miata will not require a very high spring rate as higher rated springs will not compress properly resulting in a lack of body roll during cornering, or braking. For heavier car like a Mustang, higher springs rates are required to control the heavier weight and achieve proper body roll.
Despite popular belief, body roll is not always bad for car handling, especially with a street tire. Too much reduction in body roll will decrease a car’s ability to maintain proper tire grip during spirited driving. But too much body roll will overload the tires and have a negative effect as well. Determining your cars appropriate spring rate will use the maximum ability of the tire and deliver a better driving experience allowing you to have complete control of your vehicle during all acts of spirited driving.
Coilover shocks are the muscle of the suspension system. They control how much your suspension compresses, and rebounds. They do this by allowing the hydraulic fluid or gas to pass through small orifices within the shock to slow shock travel, and decrease suspension oscillation. Higher shock opening pressure will result in a firmer shock, lower shock opening pressure will deliver a softer ride. Most race shocks provide more resistance during rebound, compression for increased grip during turning, braking, and or accelerating.
You typically see two types of shock design, twin tube or mono tube. Both the mono, and twin tube shocks have their own pros, and cons. We have listed some of these to make it easier for you to determine which shock design is better suited for your application, and needs.
Mono tube vs. Twin tube
Mono tube shocks provide more control, bigger pistons, more oil resulting in a fade free performance for a longer period of time. The normal cons of a mono tube shock is excessive rod force, meaning when the shock is compressed the rod will push back during a bump under compression, and the susceptibility to developing dents in the shock body.
Twin tube shocks pros are no rod force characteristics, and they do not dent. The cons of the twin tube design are they are more likely to experience shock fade due to excessive heat build up,. The also have an inferior gas bag design creating uneven pressure possibly causing them to eventually leak more over time.
Spring Preload or “Preloading” is when there is compression load applied to the spring with the upper perch ring to compress/stiffen the spring prior to the load of your vehicle weight being applied to the spring. This gains you a stiffer, more responsive ride, along with the ability to lower your vehicles ride height without bottoming out your suspensions shocks as easily as you would with out pre loading your suspensions springs. This requires a skilled individual that is familiar with pre-loading suspension springs, as well as corner balancing scales to ensure each corner of the car has been preloaded evenly and properly as to not upset the vehicles balance. Your cars ride height should never be lowered by the adjustable perch rings, or “sagging” your springs, doing so will result in prematurely blown shocks. The upper adjustable perch rings should always be hand tightened snug to the bottom of the spring prior to adjusting ride height at the bottom of the coilover to ensure proper shock compression, and travel. This is a required rule regardless if you’re preloading your springs or not.
Adjusting your cars ride height with most coilovers allows you to lower your center of gravity without preloading your springs, or shortening shock piston travel. This is a huge benefit of using coilovers to for lowering your vehicles ride height. The adjustable lower cup, or mount spins freely of the threaded shock body to lower, or raise your cars ride height independently. Simply loosen the collar that secures to the lower cup, or mount then screw the lower mount in, or out to your desired setting. Then securely rotate the retaining collar back to the lower mount, and reattach the mounting bolts to your cars suspension mounting points.
Excessive camber, caster, and toe can, and will prematurely wear your tires. A proper alignment is required to gain the largest benefit from your coilover system, and is also very important for safety.
You do not want to over lower your vehicle’s ride height without the addition of surrounding suspension components i.e. adjustable camber arms, toe arms, etc, as it will create suspension binding, and or decrease your cars suspension geometry. This will cause your cars suspension to bottom out, and or not articulate correctly resulting in a dangerous suspension setup.