When a performance enthusiast first sets out to customize his or her vehicle, the factory springs are usually the first to go. It's almost a universal truth that a lowered car equates to a sportier car, and most people seem to agree with this line of thinking. However, people can't seem to agree upon the best method to achieve the aggressive look.
Some people opt for the high-dollar cost of adjustable-perch shocks, some for the low-buck method of basic lowering springs and others for the no-buck method of cutting coils (which is very dangerous and should never be done).
While adjustable-perch shocks allow for a small range of adjustment, the cost can be prohibitive; they often need to be paired with a set of lowering springs to realize maximum performance potential. Lowering springs are a less costly affair, but don't provide the driver with any range of adjustment other than the spring manufacturer's preset ride height. This is where a coilover system comes to the rescue. By providing a range of height adjustment with a performance-rated suspension spring, one can have the best of both worlds. However, a full threaded-body coilover kit can run well into the $1,000 territory--an investment that the first-time enthusiast oftentimes can't readily afford.
Weapon R recognized this problem and attacked it head-on. Instead of building a complete shock assembly with an adjustable perch, it created a threaded sleeve that slides around the existing shock. This design allows for an almost infinite range of height adjustment without the high price of a full coilover system. By pairing the sleeve with a set of rate-specific performance springs, Weapon R produced the ultimate convergence of affordability and function--Circuit Pro coilovers.
Weapon R's Circuit Pro kit comes with a cold-forged polished aluminum collar that is threaded to allow the perch to be adjusted to the desired ride height. There are two sets of springs included: the main springs and the keeper springs. Both sets are cold wound from high-tensile, chrome silicon steel to ensure maximum rate consistency and are powdercoated for durability. The main springs are used for the bulk of the suspension duties, while the keeper springs add the extra progressive-rate quality for spirited driving conditions. The kits include the necessary spacers and washers to ensure proper shock alignment and a pair of spanner wrenches to allow instant changes of ride-height.
To illustrate how easy it is to properly upgrade your suspension to its full potential, we acquired a set of Circuit Pro coilovers for the ever-popular Honda Accord and forwarded them to Jeff "Jeffro" Olekosow at Pann Auto Performance in San Diego, Calif., a veteran installer of these threaded sleeve coilover systems. Bust out your tools; we've got the how-to to get it done.
After putting the car on jack stands, remove the wheels and the strut tower brace. | 
Loosen the 14mm nuts that hold the top perch, but don't completely remove them yet. This allows you to remove the bottom bolts easily without having the entire spring and shock assembly fall on you. | 
Disconnect the brake line bracket and the 14mm nut that clamps the bottom of the shock. After removing the bottom of the shock from the fork, remove the loosened 14mm nuts on top and take out the entire assembly. |
Using a spring compressor, remove the factory upper spring perch, dust sleeve, bump stop and all the washers. Then slide the plastic alignment sleeves and the threaded aluminum sleeve onto the shock. Trim any excess plastic from the alignment sleeve. | 
Tighten the threaded sleeve with the lock nuts, making sure the sleeve sits evenly spaced around the shock body. | 
Slide the main spring on the coilover assembly. Make sure you use the correct main spring (the springs are marked front and rear). Add the middle spring alignment perch and the keeper spring. The keeper spring helps to ensure contact at full extension of the shock and also adds a progressive rate quality to the ride under full compression of the shock. |
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Replace the factory bump stop washer followed by the included billet spring perch. Because the springs are of a slightly smaller diameter, the perch is used in conjunction with the factory perch to keep the spring centered under the constant compression and rebound motions. | 
Tighten the factory upper spring perch. Be sure to use the original factory bushings (or replace them if necessary) and torque the assembly to specs |
Re-install the complete coilover assembly on the car. Now would be a good time to note the height of the spring perch (by counting exposed threads). This will make it easier to fine-tune the car once it is lowered on the ground. Repeat for the other corners of the car. |  |  |
As you can see, the Circuit Pro springs are shorter than the OEM springs. This allows for a greater range of height adjustability over a kit with only threaded perches or a shock with adjustable perch height. | 
After installing all four corners and putting the car back on the ground, measure the distance from the center of the wheel to the point of the wheel well directly above it. Be sure to release the parking brake before taking any measurements. Using the supplied spanner wrenches, adjust the larger spring perch until you reach the desired ride height. Then, lock the perch in place by tightening the smaller perch against it. Remember to check for proper camber and caster to get the proper tire-to-road contact. | |