Why are they so popular and do they really improve a car’s handling? In theory, when you lower your car, you also lower its center of gravity, therefore reducing body roll and improving your handling. However, the handling characteristics of the car are not only determined by the center of gravity. You also need to consider the shock system, damping rate, road condition, tire sidewalls, unsprung weight, tire grip, suspension geometry, etc.
Right now, we’re only interested in the ever-so-popular coilover setup. There are many aftermarket manufacturers that come up with different brands and types of shocks. Coilovers are popular with racers due to their adjustability. You can set the height just right, and in some cases you can also adjust the damping to produce excellent handling.
There are two types of coils. They are true coilovers and sleeve type coilovers. True coilovers are one setup where one shock has one threaded body, while the other uses 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 coils. However, Ground Control was the pioneer of sleeved designed coilovers. We have no doubts about the benefits of true coilovers. But what about the manga guy? Works? In theory, it works just like true coilovers. In real life, it’s not even close to uncoiled spring-and-shock setups.
Ground Control, the pioneer in sleeve design technology, uses aluminum body sleeves with Eibach race springs. The spring base is supported by a single swivel plate with an Allen screw locking device. What’s wrong with this design you ask for? Like all ‘sleeve type’ coilovers, there is a good chance that the sleeve will rotate and therefore cause the spring to slip. This can happen to enthusiast drivers who like to push the car to the limit. The other thing I’m concerned about is the allen screw locking device. Such a small screw has the function 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 added the extra locking plate (with the same Allen screw that locks it in place) supposedly for added security.
Skunkworks and Aerospeed. These two companies use true coilover type locking devices. Double plates intertwined with each other. This is by far the best setup yet. But how about the sleeve? Something must be done to secure the sleeve.
These disadvantages can not only create metallic noises, but can also be very dangerous. Picture this: You’re cornering really fast, relying on that big suspension to do its job, when the lock plates/sleeve moved creating a sudden jolt in your suspension (like when you’re driving across an uneven surface) and therefore lifted his tire off the ground thus losing traction……….
So why is it so popular? Because it’s cheap ($249-$399 US) compared to true coilovers ($1,200 US and up). It looks great, it’s adjustable, and again, it makes your car look great…
beware drivers
The proper way to adjust a threaded coil suspension involves the use of a set of scales. The general idea of this type of suspension adjustability is to equalize the loads on the tires (or bias them for circular track) for cornering ability. The fact that you can lower the car with them is just an added benefit, but NOT their primary function. You should be aware that you may damage your car’s performance if you don’t fit them at least reasonably close. At best, the car may not corner as well as it used to.
At worst, it can change the handling to the point of being dangerous. This sounds like overkill, but with a threaded setup you could load up the front right and rear left tires and create a car that turns left very well, but doesn’t turn right. Even possibly hanging around. All this with the car perfectly level. You’ve got the suspension, now take the time to set it up correctly. Find a tire shop with a few corner scales and work with them to adjust tire load and ride height. The goal is to equalize the cross weights (diagonal weights). It’s not that important to match the other weights. It’s the cross weights that will sneak up on you.