Phase 3: Maximum Motorsports Front Suspension Coil-Over Kit

Phase 3: Maximum Motorsports
Front Suspension Coil-Over Kit

As expected, the Maximum Motorsports coil-over kit is well-engineered and includes excellent instructions. Due to the unique construction of Bilstein struts, the kit (p/n MMCO-1) is Bilstein-specific. A kit for Koni and Tokico struts will soon be available.

As mentioned above, the MM coil-over kit includes excellent instructions. Below, I've summarized my installation of the coil-over kit based on the provided instructions.

FIG. 1 FIG. 2 FIG. 3

Installing the Bilstein-specific coil-over kit requires mounting a split clamp collar on the strut body just above the spindle mounting brackets (FIG. 1). A threaded collar is mounted over the strut body and is seated on the split clamp collar. Unlike Koni and Tokico struts, the spindle mounting brackets on a Bilstein strut does not extend around the circumference of the strut body. As a result, the spindle mounting bracket on a Bilstein strut does not provide a suitable surface for supporting the threaded collar. The split clamp collar provides such a suitable surface.

A sheet of polymeric shim material is positioned between the strut body and threaded collar. The sheet of polymeric shim material (a yellow sheet) is shown in FIG. 2 extending from beneath the threaded collar. The sheet of polymeric shim material prevents the threaded collar from rattling on the strut body and holds the collar square with respect to the strut body such that the spring does not arch and rub on the threaded collar. With the sheet of polymeric shim material in place, the threaded collar is seated on the split clamp collar, the lower spring perch is threaded onto the threaded collar and the spring is placed onto the lower spring perch (FIG. 3).

FIG. 4 FIG. 5 FIG. 6 FIG. 7

Next, the upper spring perch assembly is assembled and mounted on the strut. A first o-ring is lubricated and placed on the strut shaft (FIG. 4) and a second o-ring is lubricated and placed in the o-ring groove in the top surface of the upper spring perch (FIG. 5). A first bearing race is then placed in the thrust bearing recess of the upper spring perch (Fig. 5), followed by a lubricated thrust bearing being placed in the thrust bearing recess (FIG. 6) on top of the first bearing race. Assembly of the upper spring perch is completed by placing a second thrust bearing race on top of the thrust bearing and then placing the thrust cone on top of the upper spring perch (FIG. 7).

FIG. 8 FIG. 9

FIG. 10

The upper spring perch assembly is then mounted on the strut shaft followed by a first spacer bushing, a thrust washer and then a second spacer bushing (FIG. 8). The strut and coil-over assembly is then mounted on the car (FIGS. 9 and 10). Before setting the ride height, it is necessary to check for adequate clearance between the upper perch assembly and the strut toweror caster-camber bottom plate. Any issues with clearance can be resolved with supplied spacer bushings of varying thickness.

After checking clearances and setting the ride height, it was time for a test drive. Even though I still need an alignment, the benefits of the coil over kit became readily apparent with a trip down my favorite roads.

Similar to switching to the Bilstein struts from the Koni struts, the ride quality is further improved. The improvement in ride quality is noticed most when traveling over discontinuities such as expansion joints and raised man-hole covers.

The biggest improvement (at least on my car) from the coil-over kit is to the handling characteristics. When entering a corner, the front end loads very uniformly. As the car settles into the corner, the front suspension provides positive and predictable feedback even over discontinuities. When exiting a corner, the suspension now unloads without the feeling of being thrown off the front spring. Rather, it rises off the spring with uniformity and control.

Prior to installing the coil-over kit, the front suspension would load and unload in a non-uniform manner. This non-uniform loading and unloading of the front suspension adversely affected handling and steering feedback. Whether these undesireable characteristics were casued by my progressive rate springs, the OEM springs location binding the front control arm bushings or both, I'm just happy that the coil-over kit took care of the problem.

Back