| Plymouth Speedway - Street Stock
Rules |
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| Chassis |
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Cars must utilize a
street-type American made chassis (1965 or newer), 105”
min wheel base. |
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((112” Wheel Base
Deduct 100 lbs.) |
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3,200 lbs. base weight
minimum at all times, including after race with driver (no refueling
after race). |
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Maximum left side weight
is 57.0% at all times. |
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Cars must utilize factory
frame sections from front steering box mount to rear of rear
spring pocket. No widening of the frame in any way. The cross
member must remain the OEM stock component and in OEM location
but may be modified for oil pan or fuel pump clearance. Weight
jacks OK. Leaf Spring cars must have stock frame to front of
rear leaf. |
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| Drive Train |
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Where aftermarket clutches
are applicable, use of a conventional clutch is required. For
definition purposes, a conventional clutch is the only clutch
allowed and the application and construction are defined in
the following manner: |
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Solid magnetic steel
clutches and pressure plates only. Clutches must be positive
engagement design. Slider or slipper clutch designs are not
permitted. No carbon fiber clutches. Clutches found not to meet
this definition will be deemed illegal. |
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In 2013, No Automatic
Transmission |
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Standard automatic transmissions
with working torque converter. |
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Manual Transmission
7¼" clutch, No carbon Fiber. Stock 3 or 4 speed
transmission with all working gears. |
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Drive shaft loop required. |
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| Suspension |
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| Wheels & Tires |
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Maximum 8” wide steel wheels only. |
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Tires Hoosier 790’s |
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| Engine |
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Engine must be cast
iron (block & heads). Use of roller rockers or roller cams/lifters.
Aluminum intake may be used. |
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Headers may be used(
NO 180’s Down Headers Only). No Dry Sump. Engine must be
located so the spark plug of the forward most cylinder is no
further back than within 1” of centerline of the upper
ball joints. Exhaust must exit behind the driver and must exit
beneath car or under frame. |
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No oil coolers in driver’s
compartment. |
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Holley 4412 (unmodified).
1" space plate or adapter is okay, but not to exceed 1"
with gaskets. |
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A fuel cell is mandatory
and cannot exceed 22 gallon capacity. Fuel line must be standard
in its size and length. |
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Carburetor Spacer: One solid material spacer, maximum height
of 1" permitted. No wedge shape spacers allowed. Both
the top and bottom surfaces must be parallel. Port hole(s)
must be vertical to the top and bottom. No beveling, tapering,
flaring or radiusing of port hole(s). Spacer may not be stepped
or undercut. No additional openings for the induction of air
allowed. Only one .075" maximum gasket per side of spacer
allowed.
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Carburetor: The Holley R4412 unmodified. All carburetors
must pass track supplied gauges. The only changes that will
be allowed are as follows: The choke plate and shaft may be
removed, jets, power valve, accelerator pump cam and accelerator
pump discharge nozzles may be changed. Idle holes may be drilled
in the throttle plates. Throttle plate screws may be trimmed
flush with the shaft. No other changes allowed. No reshaping,
polishing, grinding, machining or drilling allowed. No adjustable
(jetted) air bleeds or circuits. Gaskets must remain unaltered.
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Any other carburetor or any carburetor that does not pass
the track gauges will have a 100lb.
penalty.
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For 2013 - Intake Manifold: Edelbrock performer RPM Series
are the only intakes allowed. The intake must remain as manufactured
"stock out of the box". Manifolds must remain unaltered,
including bolt holes, painting or coating of the intake is
not allowed. Only current designed intakes allowed. Older
intakes with current part numbers are not allowed. Approved
part numbers are; Chevrolet 7101. Track supplied intake must
fit your engine.
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| Body |
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All cars must have stock
firewall and floor pan in place. Cars must have factory steel
hood, roof, fenders, and upper portion of quarter panels. All
other body panels must be made out of steel. GM to GM, Ford
to Ford, Mopar to Mopar for chassis, body and engines. Floor
pan must be at least behind driver’s seat. |
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Aftermarket bodies are
allowed. All steel, No wedge noses! |
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Aftermarket bumper covers
must cover all bumpers and brace supports and all metal must
be behind and covered by the cover. Must run a stock-type bumper
if no bumper cover is used. |
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Rooflines must have
stock appearance (“Chopped Roof’s” may result
in additional penalties) windows may go no further back than
15” from the corner of the A-Post and must go straight
up at a 90 degree angle from the door. With straight edge from
base of windshield measurement back at top. Cannot exceed 15”
or penalty may apply. |
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Rear bumper/tail light
area must be enclosed (no open tail sections). Spoilers are
OK but not to exceed 5” tall, with 60" maximum width.
No holes cut in hood for air cleaners. |
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Body exhaust, rocker
panels or any other mounted items must be no closer to the ground
than 4 inches. |
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| Roll Cage |
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Roll cages must not
be offset and must be perimeter type. Installation is subject
to technical approval. A four-point roll cage is mandatory and
must be constructed of 1-3/4” x .095 steel tubing. |
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The width of the top
roll cage bars (halo) must be a minimum of 75% of the width
of frame rails where the cage attaches. The cage must go straight
up the doors before a slight angle into the roofline. |
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Side plate on driver’s
door must be used and must be a minimum of 12” high, post
to post, ¼” thick and either be welded to the cage
or fastened with six ½” bolts. |
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Resilient roll bar padding
must be used on any roll cage piece that can be reached by an
extremity of driver. |
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A minimum of 3 protection
bars (min. ¼” wide round stock) in front of driver
in windshield area are mandatory. |
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| Battery |
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Must be securely mounted,
enclosed and above frame rails in front of rear end. |
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| Additional Rules |
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A full fire retardant
driving suit, racing gloves and Snell 95 or newer helmet is
required. |
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A suitable form of neck
restraint is recommended (a neck collar at minimum). |
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An aluminum racing seat
with belts no more than 3 years old are recommended. |
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Window nets are mandatory. |
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Additional weight must
be securely bolted to car and painted white with car # displayed. |
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All safety issues are
subject to approval by Plymouth Speedway Staff. |
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HEAD AND NECK RESTRAINT
SYSTEM HIGHLY RECOMMENDED! |
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When transponders are
supplied by the track and used for scoring, teams will be charged
$300 each if not returned to appropriate official. |
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Teams are responsible
for proper mounting of transponder, per official’s direction
at track. |
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Officials have the right
to reject any car from competing. The rules are subject to change
at official’s discretion and weight penalties may be added
for infractions. Official’s may and will alter rules at
certain events to allow participation by local cars where they
gain no unpenalized advantage. |
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Additional Race and
Procedural Rules will be distributed at a later date. Breakout
rule will be established prior to the beginning of the 2012
season. |
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Point standings will
be maintained and a 2012 Champion will be declared. The top
10 will receive point fund earnings, awards, and be honored
at the 2012 Awards Banquet. |
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Must compete in 85%
of the events. |
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| Inspections,
Mechanical Protest |
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Officials may require
an inspection of any vehicle at any time. Vehicles placing in
the first five positions must present themselves at the inspection
station immediately after the conclusion of the feature race
for such inspection and must NOT work on the car in any fashion
until told to do so by a technical official. |
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A competitor must take
whatever steps are required; including a complete tear down
of the car, as requested by official’s to facilitate inspection
of the car. |
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Failure to present
a car for inspection when requested to do so, or refusal to
take steps requested by officials, will be considered an admission
of guilt and will be grounds for disqualification. |
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Protests regarding
alleged mechanical infractions must be made prior to the feature
race being called to the track for the official lineup. The
written protest must specify, in detail, a single, specific
part or rule that is in violation before the feature event and
be given to the Chief Technical Inspector or Race Director,
along with a fee of $300. Mechanical inspection with respect
to such protest will be made following the feature race. $75
of the fee will be retained by the speedway for administrative
costs, with the remaining $225 going to the winner of the protest. |
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A protest may only be filed by a competitor in the same feature
race.
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