2006 Thriller Champion Bill Price Jr.
2007 Thriller Division Rules
BODIES AND FRAMES
NOTE: Some amended rules are for the purposes of evening up the competition
between the leaf/coil cars. Most rules are meant for the 70-81 Camaro/Firebirds
and may not reflect other leaf spring automobiles, although other models may be
added to the list if shown to be “over competitive”.
American made cars 1965 to present with minimum wheelbase of 100”. No trucks,
Jeeps, station wagons, or front wheel drives. No chopping, channeling, or
interchanging of bodies. Frame must remain stock and unaltered. Stock
manufactured bodies only, Stock rubber nose or plastic aftermarket nose may be
used if for year, make and model of car used. No hood scoops, spoilers, air
dams, skirts, etc. permitted. Full trunk floor (including inner wheel wells) is
required. Floor front/rear firewall shall remain stock with all flammable
material removed. All holes in front and rear must be COVERED with sheetmetal.
All glass, chrome, and taillights must be removed, and all doors bolted or
welded shut. Gutting of inner body is allowed only where roll cage will protrude
into doors. Cars must have wire screen or lexan windshield, supported inside at
the center by three vertical steel bars, minimum 1” by 1/8”, not less than 4”
apart. No other windows permitted. No part of front or rear window opening may
be obstructed. No rear view mirrors or radios allowed. Track scanner required.
All cars must weigh 3100 pounds, MINIMUM after the race WITH THE DRIVER. Any add
on weight must be an integral part of the car and within the wheelbase. Maximum
of 56% left side and no rear weight rule for coil spring cars. Must retain 4”
frame height. All Camaros and Firebirds, leaf and coil spring, must have maximum
55% left side weight and 47% rear weight.
ROLL BARS
Minimum 1 ½” X .120” or 1 ¾” X .095” round steel seamless (or DOM) tubing
recommended. All cars are required to have a rear vertical hoop behind and above
the drivers’ head, connected to the left and right front roll bar legs by a roof
hoop. The fron troll bar legs must follow the contour of the windshield post and
cowl. Maximum distance from the windshield to the rear of the roll bar should be
no more then 4”. A diagonal bar from the top left to the bottom right must
support the vertical rear hoop. A roll bar must connect the left and right of
the rear vertical hoop at seat height and across the floor pan at the bottom. An
additional bar must be installed at dashboard level, extended from the left
front roll bar leg to the right front roll bar leg. Roll cage must be full
perimeter, no offsetting of cages.
A minimum of three door bars on the left side and two door bars on the right
side must be used. Door bars must be convex in shape, and extend into the door
panels. Door bars must be attached to each other and the frame with vertical
bars. Minimum of 1/8” X 1” gussets must be welded into all main cage joints and
drivers’ door bars.
Minimum 1” diameter steel tubing welded directly to the cage must support the
drivers’ seat. 3” lap belts and 3” shoulder harnesses are mandatory. Crotch
belts are recommended. All belts and harnesses must be securely fastened to the
cage (harness must be attached below shoulder lever). All belts must be
un-frayed and in good appearance. Roll bars in the drivers’ area must be padded.
Headrests and drop-down style window nets are mandatory. A radiator hoop may be
utilized in the front of the cage with upright supports. Rear cage supports may
extend into the rear of the frame.
RUB RAILS/BUMPERS
Rub rails allowed. The top edge of the rub rail is to be no higher than the top
of the tire, and no lower than the hub center height. Rub rails must be made out
of round tubing max. 1 ¾” O.D. and will be tight from the inside of rail to the
body. One single rub rail per side between wheels. NO other exposed bars
allowed. Ends must not be exposed to outside of body skin. Bumpers must be
securely safety chained to each frame rail to prevent them from dropping onto
the raceway. A flat piece of metal must be welded or bolted from outside edge of
bumper flush to rear quarter panel and front fender if not using a rubber nose.
Tow hooks required on both frame rails, front and rear. No sharp edges or
cut-off ends. Ends of bumpers must be turned in and sheet metal must be flush to
the body to prevent hooking.
SUSPENSION
Suspension must remain stock and unaltered. Suspension components must be stock
to the year, make and model of car being used, with the exception of the sway
bar links. They may be all thread or fastened any other way to top of lower A
arm. NO ROD ENDS ALLOWED, MUST BE STOCK IN LOCATION. No aluminum suspension
components. No racing shocks allowed (ie. Afco, Pro, or Carrera). One shock per
wheel. Only stock springs are permitted. Springs and shocks must remain stock
and be mounted in stock location. There will be NO modification of spring or
shock mounting surfaces, and no spring pocket spacers of any kind permitted.
Stock equal length rated springs allowed with NO spacers ( NO shorties). Front
strut cars may slot holes to obtain more camber. Stock unaltered sway bars only.
All cars must use a retaining hoop at the front and rear of the driveshaft.
Driveshaft must be painted white or yellow for visibility if lost on the track.
No heim joints permitted, Magnetic driveshafts only. Locked rears only. Welded
spider or mini-spools permitted.
BRAKES
Four wheel hydraulic brakes in working order are mandatory. No balance bars. OEM
master cylinders only. No aftermarket master cylinders permitted. OEM calipers
and wheel cylinders only. Any stock brake for year, make and model hydraulic
brakes are allowed.
ENGINE
“STOCK”= YEAR, MAKE AND MODEL RULE.
*Notify tech inspector if you have any questions on rules BEFORE using the part.
No excuses will be heard for not abiding to year, make and model rules.
Any overhead valve V-8 or 6 cylinder American manufactured (General Motors,
Ford, or Mopar) product permitted, matching year, make and model of car being
used. Stock stroke and stock bore (+.040 Max). No alteration, modification, or
substitution of any engine part permitted. All engine components must be regular
production parts used on that particular vehicle. Any item replaced during
engine rebuild must be a match to the stock OEM item it is replacing. The
maximum compression ratio will be 9.0:1 and cubic inch displacement will not
exceed 358 cubic inches. No turbo or super chargers will be allowed. Fuel
injected cars must operate with stock OEM computer and have fuel pump switch on
dash clearly marked in red with fuel pump “ON/OFF”. Stock unaltered ignition
system only.
OPTIONAL ENGINE
Stock year, make and model engine may be replaced with engine which matches
manufacturer of car being used. (General Motors in General Motors, Ford in Ford,
Mopar in Mopar). All engines of this type will be 358 cubic inch maximum with a
stock stroke and a stock bore (+.040). Maximum compression will be 9.0:1.
Unaltered OEM cast iron 2 or 4 bbl intake manifold only. Stock unaltered cast
iron production cylinder heads only. (No angle plugs or Vortec heads). Stock
crankshaft, connecting rods, and stock replacement pistons only. Stock harmonic
balancer only. Aftermarket oil pan, valve covers, and timing cover allowed.
Stock unaltered 2 or 4 bbl carbs with no adapter plate only. Box stock Holley
4412 on Mr Gasket adapter plate part # 1937 (2 barrel manifold). Or part number
1929 (4 barrel manifold) allowed. Hydraulic camshaft and working hydraulic
lifters mandatory. Stock stamped steel rocker arms only. No roller or roller tip
rocker arms or stud girdles. Stock unaltered ignition system only. Stock
unaltered cast iron rear dump exhaust manifolds only.
All cars, regardless of engine being used, will use a stock unaltered standard
or automatic transmission. Standard transmission cars must use a stock flywheel,
clutch, and pressure plate of car being used only and have a blow proof steel
bell housing. Automatic transmission cars must have a stock working torque
converter. Two-inch max. diameter exhaust and two Dynomax #24200 track mufflers
are mandatory on all cars. No “H” or “X” pipes are permitted. System must be
securely fastened, leak free, and must exit behind the driver. Mechanical
throttle linkage with toe strap and double return springs required. One stock
radiator in front of engine only. All cars must carry a securely fastened and
leak free one-gallon coolant overflow tank. NO ANTIFREEZE PERMITTED!
WHEELS AND TIRES
Steel wheels must be used, maximum 7” wide. Wagon wheels and racing wheels are
allowed. (no light-weights) 15” wheels only. Track tire only. Same offset must
be used on all four wheels. No wheel spacers allowed. No use of tire softener
permitted. 1” lug nuts an all four rims are mandatory. Wheels and tires must not
extend past fender.
GAS TANKS
Encased fuel cell (maximum of 16 gallons) mandatory. Fuel cell must be centered
between rear drive tires mounted as far forward as possible on trunk floor. A
minimum 1 ½” bar will be mounted behind fuel cell to ward of puncture. Fuel cell
shut off valve must be in plain view, within drivers’ reach. Shut off valve must
be painted fluorescent RED or ORANGE and must be clearly marked “ON” and “OFF”.
Factory stock fuel pump recommended for year, make and model. No glass or
plastic fuel filters.
BATTERY
Battery may be located in the drivers’ compartment and must be enclosed in a
spill-proof container securely fastened to the floor behind driver. All
batteries must have a spill or splash cover. A battery shut off switch is
mandatory and must be in plain view, painted fluorescent ORANGE or YELLOW, and
be clearly marked “ON”/”OFF”.
NOTE* All drivers are also encouraged to read all General, Procedural, safety, and scanner rules, as they apply to all who race and participate in any Mountain Speedway event.