The make of shock absorbers, struts and strut housings may be substituted providing that the number, type (e.g., tube, lever, etc.), system of attachment, material, design and attachment points are not altered, except as noted below. The interchange of gas and hydraulic shocks absorbers is permitted.

1. The shock may be OE or OE equivalent from other vehicles of the same model, not including vehicles on the exclusion list.

2. The shocks/struts may be from the manufacturer’s accessory catalog.

3. The shock must be on the "Alternate Approved Shock" list in these rules.

4. Any other allowed shock must be commonly available (or have been available) at SCCA supporting partner Tire Rack, for regular retail sales and without custom order and may not be height-adjustable. (E.g., no threaded body coil-overs or coil-over conversions.) Parts do not have to be sourced from the Tire Rack, but they must be as they would have come off the shelf from there (e.g., no revalving), or the shock must be on a specific approval list.

If you believe there is a commonly available retail unit which otherwise fits the intent of these Rules but is not on the "Alternate Approved Shock" list, or is not available at The Tire Rack you may write in for specific approval of that brand and model.

5. The following restrictions apply to any and all allowed shocks:

A. Only one shock damping adjustment control is allowed.

B. Suspension geometry and alignment capability, not including ride height, may not be altered by the substitution of alternate shock absorbers. Aftermarket strut housings are allowed provided that they meet the category shock requirements defined herein (i.e., that no suspension geometry changes result). This includes the position of the steering arm attachment point in the case of struts with integrated steering arms.

C. The mounting hardware shall be of the original type. The use of any shock absorber bushing material, including metal, is permitted. Pressed or bonded bushings may be removed from standard parts to facilitate the use of alternate bushings which fit in the original location without alterations to the part. This does not permit the use of an offset shock bushing. A shock absorber bushing may be implemented as a spherical bearing. The bushing attaching the end of a strut to the body or frame on a strut type suspension is a suspension bushing, not a shock bushing. For cars with a bayonet/shaft-type upper shock mount, this allowance permits the removal of the shock bushing from the upper mounting plate (e.g., drilling, cutting, burning out the bushing) and replacing it with another bushing. This also includes shock bushings located in control arms, etc. This does not allow other modifications to the plate itself or use of an alternate plate.

D. To facilitate the installation of commonly available aftermarket shock absorbers, struts, or strut inserts whose shaft size is larger than the center hole of an upper shock mount assembly, that hole may be enlarged by the minimum necessary to accommodate the shock shaft size, provided the following restrictions are met:

1. The enlarged hole must remain concentric with the original configuration.

2. The enlargement of the hole does not require modification of a bearing (as opposed to a washer, sleeve, or plate).

3. Neither the hole enlargement nor the location of the shock shaft changes any alignment parameter. Provided these constraints are met, this permits enlarging of the center hole in an upper shock mount with an integrated rubber bushing, where the bushing is integral to the mount and bonded to the plate and the mount is provided by the OE as an assembly. This includes drilling out and/or removal of the metal sleeve.

6. Bump stops may be substituted or modified, provided they are in the same location as stock. (Shocks/struts with an internal bump stop on the shock shaft meet this requirement.)

7. A hole may be added to interior body panels, the engine compartment, the trunk and/or a strut bar to provide access to the adjustment mechanism on a shock absorber. The hole may serve no other purpose and may not be added through the exterior body panels.

There are no models listed at this time.