II Stock Class Rules
This is an unofficial transcription of Section 13 of the
Solo Rules. (Copyright Sports Car Club of America
2003; all rights reserved;)
It is believed to be correct, but any questions should be referred to the
official rules as published by the SCCA. Order
your own copy here.
Changes since the
2002 Rules are shown like
Further changes from FasTrack are shown like
13. STOCK CATEGORY
Cars running in Stock Category must have been series produced with normal
road touring equipment capable of being licensed for normal road use in
the United States, and normally sold and delivered through the manufacturer's
retail sales outlets in the United States. Car
not specifically listed in
Category class must have been produced,
must have met the above requirements and must have been sold through normal
U.S. dealerships, in quantities of at least 1,000 in a 12-month
period to be entered in the Stock Category.
Except for modifications authorized below, Stock Category cars must
be run as specified by the factory with only standard
equipment as defined by these Rules. This requirement refers not just to
individual parts, but to combinations thereof which which would have been
ordered together on a specific car. Any other modifications or equipment
will place the car in Street Prepared, Prepared or Modified Categories
Option package conversions may be performed between specific vehicles
of a particular make and model, but only between configurations from within
a particular model year. Such conversions must be totally complete and
the resultant car must meet all requirements of this section.
The entrant has the burden of proving that his car conforms to these
Rules by his owner's manual, manufacturer's shop manual, manufacturer's
catalogs or other official manufacturer's documentation, which must be
in the possession of the entrant at the event
ever available to the consumer from the manufacturer. At
a minimum, the competitor must be in possession of the manufacturer's workshop
manual. All manuals, catalogs and official documentation must be for non-competition
purposes. If protested competitor possess the documentation required by
this Section, but that documentation does not include sufficient information
on the protested item, the burden shifts to the protesting competitor to
prove the item illegal. Failure to provide appropriate manufacturer's documentation
regarding vehicle specifications will result in disqualification.
(OEM = Original Equipment Manufacturer's -- ed.)
Alternate components which are normally expendable and considered replacement
parts (e.g., engine and wheel bearings, seals, gaskets, etc.) may be used
provided they are the same type and size as the standard
parts and used in the same location. This does not
include camshafts, differential covers,
or ring-and-pinion sets.
Hardware items (nuts, bolts, etc.) may be replaced by similar items
of unrestricted origin. These allowances are strictly to allow components
to be replaced from alternate sources other than the original manufacturer.
They should not be construed as an allowance to replace components with
those which could be considered a 'higher performance' alternative.
Safety wire, threadlocker compounds, and locking
available as replacements through the dealers parts department, the factory,
or any other source which do not meet standard
part specifications (e.g., hardness, size, etc.) are not legal in Stock
Category, except as specifically provided elsewhere in these rules.
Cars listed as eligible in and prepared to the current national Showroom
Stock Club Racing rules are permitted to compete in their respective Solo
II Stock Classes. This does not include Showroom
Stock cars with installations of post-factory "performance packages" otherwise
known as "trunk kits". Neither Showroom Stock nor Solo II Stock cars
are permitted to interchange preparation rules. Showroom Stock cars
may use tires which are eligible under current SS rules, even if they are
not eligible in Stock.
Specific vehicle classifications are located
in Appendix A of these rules.
13.1 Authorized Modifications
If a modification is not specifically authorized in this or previous sections
of these Rules it is not allowed. It is not permitted to use illegal parts
even if they have been set to stock specifications.
Refer to Appendix
F for past
clarifications of these rules.
Accessories, gauges, indicators, lights and other appearance, comfort and
convenience modifications which have no effect on performance and/or handling
and do not materially reduce the weight of the car are permitted. This
does not allow driver's seat substitutions or
the removal of "tow hooks", a.k.a. "tie down loops". Delayed
shutdown devices such as the "Turbo Timer", which perform no function while
the car is in motion, are permitted. This does
permit the installation of an additional mirror (e.g. a "Wink"), but does
not allow the removal of the original mirror.
Hood straps or fasteners may be added.
Any fuel tank cap may be used.
Windshields may be folded (but not removed) provided the required mechanism
is standard equipment.
Alternate steering wheels are allowed, provided
the outside diameter is not changed by more than one inch from the standard
size. Steering wheels with an integral airbag may not be changed.
Spare tires, tools and jacks may be removed.
Roll bars and roll cages may be added (see Appendix C). It is strongly
recommended that they be constructed according to Section 18 of the current
GCR. Roll bars may be welded. Roll cages must be bolted, not welded, into
the automobile and within the driver/passenger compartment. A roll cage
has more than four attachment points to the body or frame, or has bracing
both fore and aft of the main hoop.
Driver restraints as outlined in Section 3.3.1 are allowed. Seats may not
be cut to allow for the installation of alternate seat belts or harnesses.
Passive restraint systems may not be removed. A horizontal "harness bar"
may be used as part of the installation hardware for allowed driver restraints.
It may serve no other purpose (e.g., structural enhancement).
Cars may add one rear trailer hitch. The resulting weight addition is allowed.
The hitch may serve no other purpose. Factory tie downs may be removed
to facilitate hitch installation.
Tow bar brackets may be installed but may serve no other purpose.
Any item that can not be held permanently in place by factory installed
fasteners may be removed.
Any tire which is O.E.M. on a car eligible
for Stock Category may be used. Non-O.E.M.
tires must meet the following requirements to be eligible for use in Stock
The tire must not appear on the following list, which may be altered at
any time by the SEB upon notification of membership.
No tire models are currently listed.
No tire models will be approved for competition during the rest of the
year after April 30 of each calendar year. Each eligible tire model must
meet all requirements of section 13.3 by April 30,
and must continue to meet them thereafter. A tire model will normally be
determined by the designation in the Tire Guide. However, any of the following
changes or similar changes (as determined by the SEB) will also be considered
to represent a new model for eligibility purposes, even if the designation
does not change: Change of tread pattern at either full or partial tread
depth; characterization by the manufacturer or distributor of a tire as
"new" after April 30.
Discontinued model tires already produced will
continue to be eligible for Solo II competition in Stock and Street Prepared
categories. This follows years of precedence on eligibility for discontinued
If a manufacturer reintroduces a tire model which
was previously discontinued, that tire will be considered a new model.
Therefore, it will have to meet the rules specified in SIIR Section
13.3 including the April 30 introduction date.|
The model of tire must be listed in a current or previous two years of
the Tire Guide and Tread Design Guide, or otherwise be approved by the
SEB. The tire model must have Department of Transportation approval.
Within each tire model, the sizes which are available must be equally available
to all competitors. Tire model variations differing from standard
specification, delivered only on a limited basis, or only to selected competitors,
may not be used.
No racing tire or recap (on any casing) may be used.
Each tire model must be sold in at least four diameters,
with a total of at least six sizes.
Tire must fit the allowable wheels and fender wells without modification.
Each tire must have non-zero measurable
tread depth (i.e., points where it is possible to obtain positive measurement
values) as described in Section 3.3.D.
Tires may not have cord visible at any time during competition.
Any type wheel may be used provided it complies with the following: it
is the same width and diameter as standard,
and as installed (including wheel spacers if applicable) it does not have
an offset more than +/- 0.25 inch from a standard
wheel for the car. The resultant change in track dimensions is allowed.
Vehicles originally equipped only with 12 inch diameter wheels, may use
13 inch diameter wheels of the same width as standard
and offset within +/- 0.25 inch of standard.
Wheel spacers are permitted, provided the resultant combination complies
with the offset requirements of this section. Wheel studs lug
nuts, and/or bolt length may be changed.
Vehicles equipped with rims having metric specifications may use alternate
rims as determined by using the following procedure.
Diameter: converting the metric measurement to inches and using
the nearest smaller inch diameter rim.
Width: converting the metric measurement to inches and using the nearest
smaller 1/2-inch width rim. Offset and track must still comply with the
requirements of this section.
13.5 Shock Absorbers
The make of shock absorber may be substituted providing that the number,
type, (e.g., tube, lever, etc.) system of attachment and attachment points
The interchange of gas and hydraulic shock absorbers
- Electronically controlled shocks may not be used on
vehicles not originally equipped with such units. Vehicles originally equipped
with electronically controlled shocks may use
shocks subject to all requirements of 13.5.
Non standard electronically controlled
active shocks are not allowed.
The mounting hardware shall be
the original type.
The use of any shock absorber bushing material, including
metal, is permitted.
This does not permit the use of an offset shock
The bushing attaching the end of the strut to the body or frame on a strut
type suspension is a suspension bushing, not a shock absorber bushing.
Suspension bushings, including but not limited to those which carry the
weight of the car and determine ride height, may not be replaced with bushings
of a different material or dimension.
To facilitate the installation of commonly available aftermarket shock
absorbers, struts, or strut inserts whose shaft is larger than the center
hole of an upper mount assembly, that hole may be enlarged by the minimum
amount necessary to accommodate the shock shaft size, provided the following
restrictions are met:
- the enlarged hole must remain concentric
with that of the original configuration;
- the enlargement of the hole does not require
modification of a bearing (as opposed to a washer, plate, or sleeve);
- neither the hole enlargement nor the location
of the shock shaft changes any alignment parameter.
A suspension bump stop is considered
to be performing the function of a spring. Therefore,
although the bump stop
may be shortened for the purpose of installing
may be substituted for the purpose of installing
The make and material of brake linings may be changed.
Substitution of clutch and brake hydraulic lines with solid metal or braided
metal is allowed on all cars manufactured before model year 1992.
Alternate brake bleeder fittings such as "Speedbleeders"
are permitted They may serve no other purpose.
13.7 Anti Roll (Sway) Bars
Front anti-roll (sway) bars:
Substitution, addition or removal of any front anti-roll bars is permitted.
Substitution, addition or removal of anti-roll bars may serve no other
purpose than that of an anti-roll bar.
The use of any bushing material is permitted.
No modification to the body, frame or other components to accommodate anti-roll
bar addition or substitution is allowed, except for the drilling of holes
for mounting bolts. Non-standard lateral members
which connect between the brackets for the bar are not permitted.
Rear anti-roll (sway) bars:
May not be removed, replaced, or modified in any way.
Standard, as defined herein, suspension
springs must be used. They may not be cut, shortened or collapsed. Cars
with swing axle suspension may be lowered sufficiently to achieve no more
than two degrees of negative camber at rest, and may use a camber compensator.
Both the front and rear suspension may be adjusted through their designed
range of adjustment by use of factory adjustment arrangements or by taking
advantage of inherent manufacturing tolerances. However, no suspension
part may be modified for the purpose of adjustment unless such modification
is specifically authorized by the factory shop manual for non-competition
Replacement control arms for vehicles having
integral bushing/arm assemblies must be standard
factory parts as per Sections 12.4 and
This encompasses both alignment and ride height
parameters, if such adjustments are provided by the stock components and
specified by the factory as normal methods of adjustment.
If authorized by the manufacturer, the use of shims, special bolts,
removal of material to enlarge mounting holes, and similar methods are
allowed and the resulting alignment settings are permitted even if outside
the normal specification or range of specifications recommended by the
manufacturer. If enlarging mounting holes is specifically authorized but
no material removal limits are specified, material removal is restricted
to the amount necessary to achieve the maximum factory alignment specification.
13.9 Electrical System
The make of spark plugs, points, ignition coil and high tension wires is
unrestricted including spark plug wires having an in-line capacitor .
On cars made prior to January 1, 1968, any ignition system using a standard
distributor without modification may be used.
Ignition settings may not be adjusted outside factory specifications.
No changes are permitted to electronic engine management
systems or their programming.
13.10 Engine and Drive Train
The engine air filter element may be removed or replaced. A replacement
element which is taller than standard
may not be used to hold the air cleaner cover open. No other components
of the air induction system may be removed, replaced or modified.
Engines may be rebored to the manufacturer's first standard
overbore, not to exceed 0.020". Sleeving is allowed to repair to the standard
bore. Only OEM-type standard
or first overbore pistons of the same configuration and of the same or
greater weights are permitted. No interchange between cast and forged pistons
Rotating and reciprocating parts may not be balanced.
Port matching is not allowed.
Any part of the exhaust system beyond (downstream from) the header/manifold
or catalytic converter, if so equipped, may be substituted provided the
system meets the requirements of 3.5. Stainless steel heat exchangers are
permitted only if the physical dimensions and configuration remain unchanged.
Modifications of any type, including additions to or removal of, the catalytic
converters, thermal reactors, or any other pollution control devices in
the exhaust system are not allowed and the system must be operable. Replacement
catalytic converters must be OEM if the vehicle
has not exceeded the 5-year/50,000 mile warranty period as mandated by
the EPA. Converters must be of the same type and size and used in the same
location as the original equipment converter(s). This does not allow for
a high performance unit. If the vehicle has exceeded the 5 year/50,000
mile warranty period, replacement catalytic converters must be OEM-type
as per Section 13.
Any oil filter may be added if not originally equipped. Canister-type oil
filters may be replaced with a spin-on type filter using a minimum amount
of hardware and connecting lines.
The installation of water expansion tanks is allowed. The installation
of oil catch tanks is allowed provided the PCV system is not altered.
A scattershield may be added. This does not
permit bell housing substitutions.
Thermostats may be added or substituted. A thermostat is a device which
controls the passage of water.
Silicone replacement hoses are permitted as
alternate components, provided they meet the requirements of section
13.0 with regard to size, shape, location, and performance equivalence.
A device for locking out reverse gear may be used.
Limited-slip differential, transmission and differential ratios, clutch
mechanisms, and carburetion, fuel injection or supercharger induction systems
must be standard as herein defined.
Any oil or grease, including synthetic, is permitted.
Valve seats and guides in older engines originally designed for leaded
fuel may be only substituted with alternate components if the dimensions
of are the same as those of the standard components.
...Jerry Mouton || email@example.com
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