Tuner Category Suspension - Full Rules
Tuner Category Suspension - Full Rules
1. Ride height may only be altered by suspension adjustments, the use of spacing blocks, leaf spring shackles, torsion bar levers, or change or modification of springs or coil spring perches. This does not allow the use of spacers that alter suspension geometry, such as those between the hub carrier and lower suspension arm.
2. Suspension bushings may be replaced with bushings of any materials (except metal) if they fit in the original location. Offset bushings may be used. The use of replacement bushings with an amount of metal greater than the amount found in the standard bushing for that particular application is limited to one link or arm per corner of the vehicle, with the same link or arm being chosen on both sides of an axle. On double/unequal arm (e.g., wishbone, multi-link) suspensions located on the steering axle of the vehicle, the use of replacement bushings with an amount of metal greater than the amount found in the standard bushing for that particular application is allowed only if there are no other replacement bushings on that axle that result in changes to alignment parameters, such as offset bushings. In a replacement bushing, the amount of metal in a replacement bushing may not be increased relative to the amount of metal found in a standard bushing for the particular application. Solid metal bushings are specifically prohibited unless there is a solid metal bushing as an OE part for the specific year/make/model. This does not authorize a change in type of bushing (e.g., ball and socket replacing a cylindrical bushing) or use of a bushing with an angled hole whose direction differs from that of the original bushing. If the standard bushing accommodated multi-axis motion via compliance of the component material(s), the replacement bushing may not be changed to accommodate such motion via a change in bushing type, for example to a spherical bearing or similar component involving internal moving parts. Pins or keys may be used to prevent the rotation of alternate bushings but may serve no other purpose than that of retaining the bushing in the desired position.
3. The following allowances apply to strut-type suspensions. Adjustable camber plates may be installed at the top of the strut and the original upper mounting holes may be slotted. The drilling of holes to perform the installation is permitted. The center clearance hole may not be modified. Any type of bearing or bushing may be used in the adjustable camber plate attachment to the strut. The installation may incorporate an alternate upper spring perch/seat and/or mounting block (bearing mount). Any ride height change resulting from installation of camber plates is allowed. Caster changes resulting from the use of camber plates are permitted.
4. Camber bolts may be installed providing these parts use the original, unmodified mounting points and meet the restrictions specified in Sport Category. Caster changes resulting from the use of camber bolts are permitted.
5. Camber kits (also known as camber compensators) may be installed. These kits consist of either adjustable length arms or arm mounts (including ball joints) that provide a lateral adjustment to the effective length of a control arm. Alignment outside the factory specifications is allowed. The following restrictions apply:
A. On double/unequal arm (e.g., wishbone, multi-link) suspensions, only the upper arms OR lower arms may be adjustable, but not both. Non-integral longitudinal arms that primarily control fore/aft wheel movement (e.g., trailing arm(s) or link(s) of a multi-link suspension) may not be replaced, changed, or modified.
B. On arm-and-strut (MacPherson/Chapman) suspensions, the lower arms may be adjustable OR other methods of camber adjustment as allowed by the previous sections may be used, but NOT both.
C. The non-adjusting control arms for vehicles having integral bushing/arm assemblies may be replaced subject to the following restrictions.
a. Arm length must remain the same as OE.
b. The part may not be adjustable.
c. The replacement arms must attach to the original standard mounting points. All bushings must meet the requirements of this section. Intermediate mounting points (e.g., shock/spring mounts) may not be moved or relocated on the arm. The knuckle/bearing housing/spindle assembly cannot be modified or replaced.
d. Any allowed arm must be commonly available (or have been available) at SCCA supporting partner Tire Rack, for regular retail sales and without custom order. Parts do not have to be sourced from Tire Rack, but they must be as they would have come off the shelf there, or the part must be on a specific approval list.
e. If you believe there is a commonly available retail unit which otherwise fits the intent of these Rules but is not available at Tire Rack you may write in for specific approval of that brand and model.
6. On swing or trailing arm suspensions, the main arms may not be modified or replaced, but lateral locating links/arms may be modified or replaced.
7. Front wheel drive (FWD) cars with rear beam axles may use shims between the rear axle and hubs.
8. The replacement arms or mounts must attach to the original standard mounting points. All bushings must meet the requirements of Tuner Category Rules. Intermediate mounting points (e.g., shock/spring mounts) may not be moved or relocated on the arm, except as incidental to the camber adjustment. The knuckle/bearing housing/spindle assembly cannot be modified or replaced.
9. Changes in suspension geometry are not allowed except as incidental to the effective arm length change.
Note: Many modern suspension designs known by other names, actually function as double A–arm designs. These include the rear suspensions on 1988-on Honda Civic/Integra, Chrysler/Plymouth/Dodge Neon, BMW E36, and most “multi-link” and are covered by the double/unequal arm rule.
10. On strut-equipped cars, the strut’s lower integral mounting bracket, for attachment to the upright or spindle, is unrestricted provided it attaches to the standard location. Any resulting change to the position of the strut centerline is allowed. Such brackets shall serve no other purpose. This does not allow for changes to the integral steering arm on cars that have the steering arm integrated with the strut body.
11. Changes in alignment parameters that result directly from the use of the allowed components are permitted. For example, the dimensional changes resulting from the use of a cylindrical offset bushing that meets the restrictions of Tuner Category Rules are allowed, including those resulting from a change in the pivoting action to:
A. About the mounting bolt, or
B. About the bushing itself.
12. Subframe mount bushings may be replaced but must attach in the standard location(s) without additional modification or changes. Subframe position may not be changed. The amount of metal in a replacement bushing may not be increased relative to the amount of metal found in a standard bushing for the particular application. Solid metal bushings are specifically prohibited unless there is a solid metal bushing as an OE part for the specific year/make/model on a trim level classed in Tuner Category.
