Note: These rules state only those modifications that are allowed. It is
the entrants sole responsibility to demonstrate that their "cars" meet these rules
at all times. Modifications performed on entered "cars" that are not specifically
identified in these rules will not be allowed and the "car" will be disqualified.
Body Rules
Body must be one of the following:
A. Stock Aurora T-Jet original,
B. Stock Model Motoring original,
C. Stock Johnny Lightning ThunderJet-500 original,
D. Stock MEV original (Including GT Racers),
E. Stock HO Detroit original,
F. Stock Road Race Replica (RRR) original, including RaceJets with the
molded in glass.
Fairground specials, factory lightened and "Fray Kit" bodies are
not allowed.
All windows must be stock (thick plastic) glass and cannot be modified.
Film windows are not allowed.
Open wheel bodies (Indy, Grand Prix etc.) are not allowed.
The body must completely cover the chassis when viewed from above except
for legal stock openings (i.e. windows).
Body must not exceed original width.
Each body must have originally equipped or reproduction bumpers.
Two screws must be used to mount the body to the chassis. Screw heads may
be modified for track clearance.
Body must be equipped with 2 screw posts.
Split screw posts may be repaired or replaced with plastic in their original
and intended position(s). No metal sleeves are permitted.
Body cannot be lightened. Wheelwells and the lower edge of the body cannot
be modified.
Body may be lowered. The body posts must touch the chassis when placed on
a chassis having full height gearplate rails with one layer of non-stretched
Scotch 33+ electrical tape covering the rails and patent number area.
Chassis Rules
Chassis must be stock T-jet copper. Bending of motor brush springs is allowed.
No other chassis modifications are allowed.
Removal of gearplate rail is permitted, patent number must be legible. No
other cutting, grinding, or drilling of chassis, gearplate, or gearplate clamp
is permitted.
Rims must be equipped with rubber or plastic tires. Stock (narrow) T-jet
axles must be used. Spacers with a maximum diameter of 3/16" may be used on
the front axle only to limit lateral movement. Maximum front axle lateral
movement is 1/32"
Spacers must be located outside of the chassis. External rear wheel weights
and/or hubcaps are not allowed.
Solder or glue is allowed to attach gears to shaft.
Gearplate must use stock brass 14-tooth armature pinion and 24 tooth idler
and driven gears.
Guide pins must be either stock black Aurora or mass-produced molded plastic
guide pins. Pin length may be shortened. No rear or swivel guide pins permitted.
Gluing of guide pins to chassis and countersinking of the guide pin screw
hole are permitted.
Cars must use original stock, reproduction stock, or narrow double-flanged
plastic T-jet rims mounted on stock (narrow) T-jet axles. The width of the
chassis must be no wider than 1.085 inches, measured at the outside edges
of the rims. Any type of slip-on plastic or silicone tire is allowed. Minimum
front tire diameter is 0.330". Minimum rear tire diameter is 0.355".
Front axle may be located in any stock wheelbase position. The center (truck)
position must not be used.
Any original Aurora pancake style "armature" with no more than two "stack"
gray laminations and with all of its original windings "unmodified" may be
used and may be balanced. (No stock-replacement, dewind, rewind, turned or
epoxy coated motors are allowed).
When measured across two different commutator segments, "armatures" must
have an ohm rating of 16.0 ohms or higher at an average room temperature of
65ºf - 75ºf.
Magnets must be stock Aurora that fit the T-Jet chassis. J.L. or Super II
magnets are not allowed. Magnets must not be cut, drilled, or sanded. Legal
magnet setups will not pick up a John Deere 10 gram groove pin (stock #25H534)
completely off of the table. (Note: Test is performed on the assembled chassis).
Magnets may not be shimmed.
Any and only copper/carbon brushes, flat top and bottom, are allowed.
All gearplate gears must be stock T-jet brass gears. Gears may be polished
to provide a smooth mesh. Drilled, grooved, or lightened gears are not allowed.
Rear end gears must be stock T-jet 9 tooth drive pinion with stock T-jet
15 tooth crown gear.
Pickup shoes and springs must be stock copper T-jet or stock replacement.
No weights, wires, or creative bends allowed. Pick up
shoe travel must not be limited in any way. Ski shoes are not allowed.
Springs may be cut, crushed or lengthened.
"NITRO" Class Rules
Note: These rules state only those modifications that are allowed. It is
the entrants sole responsibility to demonstrate that their "cars" meet these rules
at all times. Modifications performed on entered "cars" that are not specifically
identified in these rules will not be allowed and the "car" will be disqualified.
Complete car rules
The complete "car" must not weigh less than 19.0 grams and no more than
23.4 grams.
The complete "Car" must not exceed the maximum allowed width of 1.3125"
(1-5/16").
Body rules
"Bodies" must be based on and visually represent an actual full-scale car.
"Bodies" must be manufactured by either the process of casting or injection
molding, be made of resin or plastic, have two screw posts and may be painted.
"Bodies" must be originally manufactured with the intention of being mounted,
with the use of 2 screws via 2 body mounting posts, on a/an: Aurora Model
Motoring (which includes: Vibrator, ThunderJet, Wild Ones, Tough Ones and
Xlerators), Bachmann, Faller, Model Motoring ThunderPlus, Marx, Eldon or Tyco
"S" series "HO" chassis.
"Bodies" with cast in handling pans or exaggerated details such as unrealistic
or inappropriate hood scoops, sloped sides or snow plow noses are not allowed.
No ballast or fillers, other than color pigment, are allowed in the plastic
or resin.
Maximum overall "Body" width is 1.200".
The maximum thickness of the sides of the "Body" including items such as
fender flares and running boards is 0.125".
Spoilers, wings and other external detail may be added to the "Body" however
these items cannot cause the body to exceed the body width limit.
With the "Body" mounted securely to the "Chassis" and viewed from above,
the "Body" must cover the "Chassis" except through windows and radiator exhaust
vents. Unrealistic or overly large windows are subject to repair (See Body
Rule 23)
With the "Body" mounted securely to the "Chassis" and viewed from the side
of the "Body", the upper edge of the top-plate, minus rails, cannot be above
the top of the "Body" as measured at the rear of the top plate. (i.e. The
gear plate cannot stick out the rear window)
"Bodies" must be fitted with all the manufacturer's original or exact replicas
bumpers, heads, rollover bars, etc. in their stock locations.
The "Body" to "Chassis" mounting posts may be shortened by cutting or grinding
for the purpose of lowering of the "Body" on the "Chassis assembly" provided
that Rule 10 is not violated.
Cracked or broken "Body" mounting posts may be repaired or replaced with
the use of glue and/or a plastic sleeve around the original post or a plastic
tube in place of the broken post.
Other than the plastic post reinforcements stated in Rule 13, no additional
weight can be added to the "Body".
The "Body" may be lightened by removing material through the process of
grinding or scraping, as long as rules 10 and 11 are not violated.
"Bodies" that have a separate roof and windshield casting/molding, and have
molded in "interiors" (also know as Hardtops, e.g. Aurora's '65 Mustang),
may completely remove the "interior" portion of the "Body".
Front and rear wheel wells may be opened up for tire to wheel well clearance.
This opening when measured from front to rear must not exceed 140% of the
tire diameter. Bodies that are manufactured with oversize
wheel wells will be allowed if the oversize wheel wells resemble those on
the original 1:1 car. In those cases the wheel wells must not be modified.
Examples would be the Dino and Cheetah.
With the body mounted securely to the chassis, the highest point of the
wheel well arch must not exceed more than 0.125" from the top of the tire.
Wheel wells must not be modified in such a way to allow the use of any other
wheelbase than that was originally intended by the manufacturer of that body.
Any body mounting screw may be used. Non-magnetic screws are recommended
so that a loose screw will not be picked up by a passing car, thus causing
damage to the car and / or the track.
Both front and rear screws must be used and must secure the body to the
chassis at all times.
The front windshield must be plastic or resin, clear or painted, may be
glued in place and must fill the frame. "Tape" windshields are not allowed.
The side and/or rear windows may be removed.
Bodies that violate rules 9 and 10 by having illegal openings such as too
large or unrealistic windows, missing engine covers and open truck beds may
be repaired by gluing a 0.025" minimum thickness plastic cover over the opening.
The repair must be made so that its thickness can be checked using a micrometer
having a ¼" diameter anvil.
Chassis Assembly Rules
Only original Aurora ThunderJet "chassis assemblies" with copper electrics
are allowed.
The "chassis" axle and armature holes may be slightly opened up for increased
clearance.
The "chassis assembly" must not be fitted with "bushings".
The "chassis" may be trimmed slightly (no more than .010") to allow for
crown gear tooth clearance.
Any original Aurora pancake style "armature" with no more than two "stack"
gray laminations and with all of its original windings "unmodified" may be
used and may be balanced.
NITRO considers turning of the armature a separate operation and armatures
with turned stacks are not allowed.
When measured across two different commutator segments, "armatures" must
have an ohm rating of 16.0 ohms or higher at an average room temperature of
65ºF - 75ºF.
Any and only original Aurora motor magnets without the "dimple" or Johnny
Lightning magnets must be used.JL magnets maybe lightly
sanded for purposes of fitting them into the chassis.
Magnet shims may be used. Aurora magnets may be shimmed with ferrous material.
JL magnets may be shimmed with non-ferrous material. No shims are allowed
on the top of or under the bottom of the magnets.
Any and only carbon/copper motor brushes are allowed. The motor brush spring
may be bent to adjust tension and improve electrical contact.
Only 14 tooth "armature" gears are allowed.
Only 24 tooth brass idler and driven gears are allowed.
Only 9 tooth or 12 tooth rear end (final drive) pinion gears are allowed.
Only 15 tooth crown gears are allowed. The crown gear boss may be trimmed
or a spacer may be added to adjust for proper gear mesh.
Gear tooth friction surfaces may be de-burred by polishing, filing or sanding.
Gears may not be chamfered, lightened or "relieved".
Gear and amature shafts may be adjusted up or down
raltive to the top plate gears. The shafts must not be trimmed, cut, or shortened.
Solder or glue may be used to secure the gears to their respective shafts.
Any front and rear wheel, tire and axle assembly may be used. Minimum front
tire diameter is 0.330". Minimum rear tire diameter is 0.355". Tires will
be measured while mounted on the rim, using a BSRT tire guage or micrometer.
Tires may be up to 0.005 smaller than the minimum size to allow for tire wear.
Front and rear axle washers (spacers) are allowed.
Maximum overall width of any part of a Fray car must be less than 1-5/16"
(1.3125"). Maximum front axle lateral movement is 1/32"
The center front axle truck hole must not be utilized.
The "step" in the pick-up shoe must remain intact and be unaltered, except
for only that the first bend may be changed slightly so that proper "pick-up
shoe" to "rail" contact can be achieved. No attempts to "flatten" the "step"
are allowed. The area between bend 1 and bend 2 may be "flattened" to achieve
better contact with the "rails". The front, vertical, slotted portion of the
pick-up shoe may be bent to limit shoe travel. The rear, hook portion of the
pick-up shoe may be bent to limit shoe travel and adjust shoe tension. The
chassis' copper pickup retainer may be bent slightly to improve electrical
contact.
The pickup springs may be cut, stretched or smashed.
The vertical "gearplate rails" above the "upper horizontal plane" may be
removed. No amount of material may be removed from the "gearplate" at or below
the "upper horizontal plane". The serial/patent numbers and letters must remain
intact.
Only original Aurora black plastic or identical replacement plastic guide
pins must be used. The pin portion may be cut, trimmed,
or bent. The guide pin may be glued in place. Countersinking of the
guide pin screw hole is permitted.
Johnny Lightning Class Rules
JL Body Rules
Note: These rules state only those modifications that are allowed. It is
the entrants sole responsibility to demonstrate that their "cars" meet these rules
at all times. Modifications performed on entered "cars" that are not specifically
identified in these rules will not be allowed and the "car" will be disqualified.
Body must be JL bodies produced to fit the Aurora T-jet chassis. Split screw
posts may be repaired or replaced with plastic in their original and intended
position(s). No metal sleeves are permitted.
Body cannot be lowered. Fender wells may be cut for tire clearance provided
general body rule #1 is not violated.
All windows must be stock. Lower edges of windows and the interior of the
body can be trimmed to avoid interference with the chassis and/or gears.
Bodies must be mounted with stock JL Philips head screws. Screws cannot
be modified.
JL Chassis Rules
Chassis must be stock JL Tuff-One. Bending of motor brush springs is allowed.
No other chassis modifications or replacements are allowed.
Stock JL axles and front and rear rims must be used. Front rims must be
equipped with rubber or plastic tires having a minimum tire size of 0.370".
Any commercially available slip on rear tire can be used on stock rims.
Armature, Gears and Magnets must be stock as provided with the JL car. Motor
brushes must be stock JL or Thunderbrushes.
Guide pins must be either stock black Aurora or mass-produced plastic guide
pins identical in dimension to the stock Aurora pin. Pin length may be shortened.
No rear or swivel guide pins permitted. Gluing of guide pins to chassis is
permitted.
Pickup shoes and springs must be stock JL silver or stock copper T-jet.
No weights, wires, or creative bends allowed. Pickup
shoe travel must not be limited in any way. Pickup springs may be cut,
crushed or lengthened.
