The following specifications
have been prepared by Montpelier Motor Speedway and their officials as
guidelines for the construction of a Thunder Car. No express or
implied warranty of safety shall result from publications of or
compliance with these rules. They are intended as a guide and are in
no way a guarantee against injury or death to participants,
spectators, or others.
Anything not covered by these
guidelines, must be approved, by the promoter or his assigned
steward. These specifications are intended to be in effect throughout
the 2013 auto-racing season. However, continuous development in auto
racing and technology may necessitate changes in these guidelines, and
management reserves the right to change them at any time.
THE PURPOSE OF THIS DIVISION IS TO
PROVIDE AN INEXPENSIVE WAY FOR A BEGINNER TO GET INTO STOCK CAR
2013 Rule Changes indicated
1. All thunder
cars must be strictly stock for make and model of car.
2. Inspections may be
made at anytime at the discretion of track officials.
1. 3200 lbs with 500 CFM
#4412 two barrel Carburetor
2. 3400 lbs with OEM
four barrel Carburetor
3. Top five may be
weighed immediately after the feature.
1. The stock steel
unaltered floor pan, stock front firewall will be used only.
2. No holes in the hood,
roof or trunk lid. Hood will be kept in place at all times. All stock
sheet metal will be mounted on car at all times.
3. All doors and body
panels will be welded together.
4. A complete firewall must
seal trunk form driver’s compartment. 16 Ga. sheet metal minimum.
5. The only modifications
to the floor pan or firewall are for repair of rust areas. All holes
in driver’s compartment must be covered with minimum of 16 Ga. sheet
Fuel cell will be
mounted in trunk area, between frame rails. Stock gas tank will be
Fuel cell must be above
center line of differential housing or 12” above ground, whichever is
Max. 22 Gal. fuel cell.
6. Trunk floor may be cut
to accommodate fuel cell. Minimum of 2-12 Ga. 1 ˝” safety straps.
7. No spoilers allowed.
8. Aftermarket nose
9. Stock style bumper only
if nose and tailpiece are not used. Bumper will be securely attached
in place in stock location welded to frame rails. No front or rear
bumper shocks allowed.
10. Ballast will be allowed,
but must be bolted to frame or to cross member rails. All ballast will
be painted white with number of car in contrasting color.
11. No Uni Bodies
INTERIOR, WINDSHIELD, AND GLASS
1. A four-post roll cage
must be used with three door bars on driver’s door. Driver’s door must
have 1/8” steel plate on door bars. Window net on driver’s side is
mandatory. Two bars on passenger side only.
2. Cage can be braced,
rearward to the frame where is starts to kick up over the rear end.
Bars may be added from firewall forward to protect frame and radiator.
Front firewall, front or rear hoods optional.
3. All glass,
headlights, tail lights must be removed prior to arrival at the track.
No broken glass shall be in the car. Car must be swept clean.
Full 3/8” bars minimum, in front of driver. 4 bars minimum. 3/8” solid
bars with wire mesh.
1. Engine block will be
stock O.E.M. small block passenger car, for make and model of car.
No 400+ engines. 350
C.I. Small block only for make and model of car. 350 C.I. Ford, 360
Block numbers will be
checked. All blocks will have legible numbers.
2. Entirely Stock (May Run Aftermarket Valve
Covers and Oil Pan)
3. Aftermarket air
4. Engine will be
mounted in stock O.E.M. position.
5. Stock rear transmission
mounts only, with stock transmission mount cross member, bolted to
6. Must idle stock--850
7. No engine swapping
between make and model of car.
8. No external vacuum
Drive shaft and all ballast must be painted white with number of car
in contrasting color. Drive shaft hoop mandatory under drive shaft 6”
to 8” behind transmission tail shaft. 1/4" chains may be used.
stock heads only. No after-market, bowtie, or aluminum heads. No port
work allowed. No roller rocker. Stock for make and model of car.
be strictly stock for make and model of car. Cast iron intake manifold
only. No high-rise truck or marine type intakes allowed. No porting or
polishing of any kind allowed. You will pull carburetor to inspect
intake at track official’s discretion.
EXHAUST MANIFOLD - Cast Iron
Carburetor must be stock O.E.M. for make and model of car.
O.E.M. stock 4BBL carburetors
allowed, must be for make of car.
Holley 2BBL-4412-500 C.F.M., with
stock 1.378” maximum venture bore allowed.
No double pump carburetors allowed.
Aftermarket filters allowed as long
as it will not require cutting hole in hood to fit on motor.
I 69 Speedway 2 barrel
Rochester is legal.
1. Stock manual fuel pump
mounted in stock location on engine. Must shut off fuel supply to
engine when engine is not running.
2. No electric fuel
3. All fuel lines routed
through drivers compartment will be enclosed inside rigid tubing from
bending rear firewall through front firewall and sealed at both ends.
1. No dual point
2. Stock coil in stock
location, must use stock distributor.
must be securely mounted inside plastic battery safety box. Plastic
battery case will be securely mounted to frame or roll cage bars
behind driver’s seat.
Battery box top will be securely mounted to battery box.
lines running from battery through front firewall will be mounted in
flexible tubing, I.e. garden hose, etc. , and sealed at both ends.
5. Ground wire will be
directly to frame or roll bar.
1. O.E.M. stock automatic
transmission with three forward gears and one reverse must function in
all gears with engine idling.gvb5g67y7u4 li78
350 Turbo, Powerglide, and Stock Cast Iron Manual Transmissions are
allowed. No aftermarket racing transmissions allowed (Berts,
Brinns, or Falcons, etc...)
No Aluminum flywheels. Must utilize a stock single plate clutch.
1. Stock radiator in
2. Aluminum or plastic
3. No electric fans.
REAR END DIFFERENTIAL
1. Post traction limited
slip, locked or welded, spider gears allowed.
2. 9” Ford rear end
differentials allowed in non-Ford cars. Floaters will be allowed.
1. No altering of stock
2. Brake pedal must
remain in stock location.
3. Cars must have fully
functional brakes on all four wheels.
4. Rear disc brakes
allowed. Brake assemblies must be in stock location on all four
5. No brake bias or
proportional valve permitted.
6. One O.E. M. master
cylinder only for make and model of car.
1. Body and frames must be
O.E.M. stock for make and model of car in O.E.M. location. No
switching or shifting of any body parts allowed.
bumper-to-bumper O.E.M. stock frame for make and model of car, other
than repairs needed to repair areas due to rust or damage.
3. Repairs to stub must
retain exact O.E.M. measurements for make and model of car.
1. O.E.M. stock suspension
only for made and model of car. Front A-frames and rear suspension
arms, O.E.M. stock for make and model of car. May run upper
tubular A arms.
2. No coil-over,
overload, cargo ratchet or air assisted shocks permitted.
3. Racing shocks permitted
must fit in same brackets as O.E.M. stock, front, and rear, for make
and model of car.
4. Racing springs allowed,
must maintain stock O.E.M. frame and body heights for make and model
5. Metric cars can
reinforce O.E.M. upper A-frames only.
6. No lift bars or
recovery shocks or spring recoils allowed.
7. No screw jacks.
1. Reinforce racing type
wheels mandatory. Right rear bead lock only.
2. Maximum wheel width
3. One-inch lug nuts are
4. Any loss of tire and or
tire & wheel requires a driver to find safety or pull off of racing
surface to infield or exit track immediately.
1. Must run 70 series DOT
approve, 15” DOT name brand tires on 8” wide rim (maximum).
2. Maximum tire is
3. No grooving, sipping
or soaking allowed
4. Absolutely no racing
tires, disguised as DOT street tires allowed.
1. Fuel cell mandatory.
22 gallon maximum capacity. Bracing in trunk permitted.
2. Fuel cell will be
mounted in trunk are, between frame rails with 1 ˝” clearance on all
four sides. Minimum of two 12 GA x 1 ˝” wide safety strapping,
mandatory for safety.
3. Trunk floor may be
cut to accommodate fuel cell.
4. O.E.M. fuel tank will
5. No electrical fuel
6. Fuel line from trunk to
engine compartment must be steel or steel braided. No copper or rubber
allowed. Any fuel line run through driver’s compartment will be
enclosed in rigid tubing from inside trunk area to inside engine
compartment will be sealed at both ends.
7. Tech inspector must
8. Fuel cell will be a
minimum of 12” above ground or above centerline of rear end
differential housing, whichever is higher.
APPEARANCE/ CAR NUMBERS
1. Numbers with letters are
allowed. Make the letter large enough to be seen from the scoring tower.
2. Numbers must measure
minimum of 22” high by a minimum of 15” wide. The thickness of the
number must be no less than 3”.
3. Color of the number
must be contrasting with the car color.
4. Numbers must be located
on both doors and roof of the car. Put the roof number so it can be
seen from the tower when the car is in the front stretch.
5. Car number above the
right rear bumper is recommended.
6. The car must be washed
prior to each nights event . Throughout the night, if the number
becomes covered with mud, it must be washed before participating in
the next event so the scoring team can read the number.
7. If you are caught
cheating after a race, you will be disqualified for the night. You
will lose winnings and points for the event. If you are caught
cheating a second time, you will be barred for two weeks and lose all
points for the year.
It is the sole responsibility of each competitor for the
effectiveness and proper installation, per the manufacturer’s
specifications to be adequate for competition at every event. Each
competitor is expected to investigate and educate themselves for
continuing improvement regarding their own personal safety
Seat Belt/Restraint System
1. Each car should be equipped with an approved 5 point seat belt
restraint system within the date of the belt expiration. Seat belts
restraint systems shall be installed in accordance with the
directions and application of the system supplier or manufacturer.
2. Seat belt webbing that comes into contact with any sharp or
unradiused metal edge should be protected from that edge by means of
push on grip vinyl trim.. Seat manufacturers supply the seat with
trim protecting the webbing from abrasion or cutting under impact
conditions and should be used to their specifications.
Helmet, Fire Suit, Gloves, Window Net, and Other
1. Each driver must wear an approved full face helmet, fire suit
with top and bottom, and racing shoes and gloves.
The driver should wear the helmet and other
safety equipment in accordance with the directions provided by the
helmet manufacturer and/or supplier and the driver should make sure
that equipment dates and quality/protection needs meets the needs of
2. Head and Neck restraints are strongly recommended.
3. Driver door net or triangle is required
4. Fire Extinguisher easily assessable to driver is recommended
bar padding is recommended around driver’s compartment.
RACEceiver (one way) Radio is mandatory and shall be used by drivers
during all wheel packing, hot laps, heat races, and B/A Main
1. Officials may change any of the
Thunder Car rules in the interest of fairness and safety at any time
and all decisions are final!
Cars may be inspected at anytime. If car is found illegal,
driver will lose all money and points for that night.
Top 5 Finishers will be weighed immediately following feature unless
Thunder Cars will follow all track procedures and car entry
THE PROMOTER/TRACK OFFICIALS
SHALL BE EMPOWERED TO PERMIT MINOR DEVIATION FROM ANY OF THE
SPECIFICATIONS HEREIN OR IMPOSE FURTHER RESTRICTIONS THAT IN THEIR
OPINIONS DO NOT ALTER THE MINIMUM ACCEPTABLE REQUIREMENTS. NO
EXPRESSED OR IMPLIED WARRANTY OF SAFETY SHOULD RESULT FROM SUCH
ALTERATIONS OF SPECIFICATIONS. ANY INTERPRETATION OR DEVIATION OF
THESE RULES IS LEFT TO THE DISCRETION OF THE PROMOTER/TRACK OFFICIALS.
PROMOTER/OFFICIAL DECISIONS ARE FINAL.
The absence of a specific rule does
not imply approval, consent, or permission regarding the subject.