Why are they so popular and really improve a car’s handling? In theory, when you lower your car, you also lower your center of gravity, therefore reducing body roll and improving your handling. However, the car’s handling characteristics are not only determined by the center of gravity. You should also take into account the damping system, the elasticity index, the road condition, the sidewalls of the tires, the unsprung weight, the grip of the tires, the geometry of the suspension, etc.
Right now we are only interested in the popular coilover setup. There are many aftermarket manufacturers that come with different brands and types of coilovers. Coilovers are popular with runners because of their adjustability. You can set the correct height and in some cases you can also adjust the damping to produce excellent handling.
There are two types of coilovers. They are true coilovers and manga type coilovers. True coilovers are a configuration in which the shocks have a threaded body, when, like the other, they use a ‘sleeve type’ thread. One of the oldest and best known manufacturers of coilovers is H&R. Now, there are different companies like Tein, Intrax, etc. They also make coilovers. However, Ground Control pioneered sleeve designed coilovers. We have no doubts about the benefits of true coilovers. But what about the type of manga? Works? In theory, it works the same as true coilovers. In real life, it doesn’t even come close to coilover-less spring and shock setups.
Ground Control, the pioneer in sleeve design technology, uses aluminum sleeves with Eibach race springs. The spring base is supported by a single turntable with an Allen screw locking device. What’s wrong with this design, you ask? Like all ‘sleeve type’ coilovers, there is a good chance that the sleeve will rotate and therefore cause the spring to slide. This can happen to enthusiastic drivers who like to push their car to the limit. The other thing that concerns me is the Allen screw locking device. Such a small screw takes care of maintaining the tension and spin that the car generates when driven by an enthusiast.
Weapon-R Tuner 2 coilover conversion. This is basically the same with Ground Control, except it added the extra lock plate (with the same allen screw that locks it in place) supposedly for added security.
Skunkworks and Arospeed. These two companies use true coilover locking devices. Double interlocking plates. This is by far the best configuration so far. But how about the sleeve? Something must be done to secure the cover.
These disadvantages can not only create a metallic noise, but they can also be very dangerous. Imagine this – you’re cornering really fast, relying on that great suspension to do its job, when the lock / sleeve plates moved creating a sudden jolt to your suspension (like when you’re driving across a rough road surface), and, therefore, he lifted his tire off the ground thus losing traction ……….
So why is it so popular? Because it’s cheap ($ 249- $ 399US) compared to true coilovers ($ 1,200US and up). It looks great, it’s adjustable, and again it makes your car look great …
Beware of drivers
The correct way to adjust a threaded coil suspension involves the use of a set of scales. The idea of this type of suspension tuning is to equalize the loads on the tires (or deflect them for the circular track) for cornering ability. The fact that you can lower the car with them is just an added benefit, but it is NOT their main function. You should be aware that you can hurt your car’s performance if you don’t adjust them at least reasonably close. At best, the car may not turn as well as it used to.
At worst, it can change your driving to the point of being dangerous. This sounds like overkill, but with a threaded setup you could load the front right and rear left tires and create a car that turns left just fine, but doesn’t turn right. Possibly even spinning. All this with the car perfectly level. You have the suspension, now take the time to set it up correctly. Find a tire store with some corner scales and work with them to adjust tire load and ride height. The goal is to equalize the cross weights (diagonal weights). It is not so important to match the other weights. It’s the crossweights that will sneak up on you.