Overview: The Pure Stock Class is closely based on the traditional BSA
Pinewood Derby rules and most restrictive division in WIRL racing. Cars racing
in this division require stock BSA wheels, standard axles, and a wheelbase of
4 ½ inches or less.
BODY:
S1
The main body structure must be made of wood.
Car is eligible to race for a 12 month period
from registration date. (Example: a car registered in November 25th, 2007 is
eligible to race until 12 midnight on November 25th, 2008)
S2.
Body Specs:
A.
Width - Not to exceed 2 3/4 inches (7cm)
B.
Length - Not over 7 inches (17.8 cm)
C.
Weight - Not over 5 ounces on scale accurate to 1/10 ounce.
D.
Height- Not to exceed 2 3/4 inches (7cm)
E.
Center Rail Width Clearance – At least 1 3/4 inches (4.5 cm) minimum along
entire center length of car.
F.
Bottom Clearance - at least 3/8 inches (.95cm) from track. Fender flairs with
less clearance are acceptable as long as the center rail width clearance is
the same in rule S2E.
G.
Wheelbase – No More than 4 1/2 inches from center of front axle slot to center
of rear axle slot (11.43cm)
S3.
Body design may be enhanced by adding other stable materials such as plastic
or metal. All additions must be firmly attached and conform to the size
specifications.
S4.
No part of the car body may protrude in front of the starting peg.
S5.
There should be an unpainted, unfinished wood surface on the underside of the
car at least 1/2 x 1" (12 x 26 mm) to be used for a WIRL car number stamp.
S6.
The following items are PROHIBITED:
A.
Springs
B.
Starting devices or propellants
C.
Electronic or lighting devices
D.
Liquids, wet paint, oil, sticky substance, or powders of any kind (other
than axle lubrication)
E.
Glass or excessively fragile parts
F.
Wheel bearings
G.
Loose objects on car
H.
Magnets
WHEELS:
S7.
BSA wide wheels are required for the stock racing category. Outer wheel
surface may be lightly sanded, shaved, or polished to remove surface
imperfections and mold casting burrs, but must not be reshaped in any way in
an attempt to lighten the wheel, minimize tread contact or alter aerodynamics.
The fluting and other BSA markings on the outside wheel area must remain
visible.
S8.
The
following wheel modifications are PROHIBITED:
A.
Rounding of wheel edges
B.
Grooving, H-cutting or V-cutting
C.
Altering of wheel profile
D.
Narrowing the tread surface
E.
Drilling sidewalls
F.
Hollowing, sanding, or otherwise removing or modifying plastic material
from inside the wheel
G.
Filling of wheel surface with any type of material
S9.
There must be at least four wheels on the car, however, it is not required
that all four wheels make contact with the track surface.
S10.
The wheels must be attached directly to axle and spin freely.
AXLES:
S11.
Readily available nail or pin type axles are allowed with an overall diameter
of no less than .084 inches (2.13mm). Some polishing and/or modification is
allowed as long as overall diameter is not reduced.
S12.
Axles must not
be connected to any device that mechanically alters rotation and spin.
S13.
Lubricants must be dry on the axle at race time. Wet, oily, or greasy axles
are not allowed. Over-application of lubricant which results in excessive
shedding onto the track is not allowed. Approved lubricants include (but are
not limited to) graphite, Teflon, and Nyloil.
