2008 358 MODIFIED RULES
1. Bodies: Cutlass Supreme, Grand Prix, Probe, Cavalier, Sunbird, Lumina, GrandAm, Daytona, Thunderbird (BUT NOT LIMITED TO), no fan or ground effect cars, no exotic bodies, front wheels and tires must be fully exposed.
A. Maximum
roof width 52”, minimum 48”. Roof
must be centered on roll cage. No offset
bodies- must be centered on frame.
B. Length
of roof maximum 60”, minimum 48”. NO
FLAT ROOFS.
C. Overall
height (top of highest point) maximum 61” minimum 52” from ground.
D. All
roofs must be single ply one piece fiberglass; leading edge must be minimum 33” in
front of rear axle centerline and maximum 48”.
E. Rear
deck/spoiler must not exceed 50” from ground to the tip of the deck/spoiler/trunk
(with driver).
F. Window openings:
1) Side
minimum 12” vertical front and 14” vertical rear by 30” wide.
2) Front
window opening 8” vertical measured from lowest point of roof or roll cage to highest
point on hood (including hood scoop).
G.
Maximum body width anywhere 68”, minimum 44”.
H.
Side door panel maximum 70” in front of center of rear
axle, door must be straight up and down within that measurement. Variations for molding will be acceptable. Front door extensions will be allowed up to
20” minimum behind front axle centerline. All
extensions and rear quarter panels must have a max lip rounded or 90 of 1 ½” top and
bottom, facing inside only.
I.
Rear quarter panels must match. Two-inch (2”) fender flares are legal as long
as a 68” maximum body width is maintained. Rear
quarter panels can extend back to 48” maximum (measured from center at rear axle to
rear and car including spoiler).
J.
No covered window openings, except
for mandatory front screen, (no aluminum) maximum 1” x 1” openings recommended. Screen must be suitable.
K. Rear
trunk lid must be fully enclosed from quarter panel to quarter panel.
L. Front hood, nose, and front spoiler
can be no wider than 36” and may not extend anymore than 20” in front of axle
centerline, also they may have 2” max lips up or down on side following contour of
body. Hood must have complete sides.
M. Hood
scoop cannot start anymore than 25” forward of center of carburetor, hood scoop can
not be wider than hood.
N. Minimum
ground clearance 2 ½”.
O. Body
and inner panels must be aluminum or steel. (Roof
must be fiberglass only).
2. ROLL CAGE: Round steel rollover bars are mandatory. Front and rear roll bars must be connected at tip (cage type). Proper bracing and triangulation on front and rear roll bars is recommended. A minimum of one diagonal bar across the top of the roll cage is recommended. Roll bars at 1 ½” diameter by .120-wall will be the minimum size allowed and roll bars at 1 ¾” minimum .095 wall are recommended.
3. CHASSIS:
A.
Only homemade box (2x4) frames permitted. The fourth side must
be vertical. No holes may be cut in frame rails to lighten. Steel frame rails only. All
frame rails must be .120” wall thickness only. At the discretion of the officials, it
may be necessary to drill a 3/16” hole in frame for inspection of thickness.
B. Chassis width shall be as follows: front 24” minimum 35” maximum, rear 26” minimum 35”maximum. All measurements shall be taken from outside of frame rails. These measurements shall be taken at both top and bottom of frame at its longest length. Clips, subframes, etc. will be considered part of frame. Minimum length of (2x4) frame rails must start maximum at 14”in front of rear axle centerline and extend to front of radiator. All kick up material must be same specs as roll cage or frame material.
C. Minimum
frame width must be 26” measured at rear roll bar (top and bottom). Left and right
frame rail must measure equal distance from drive train centerline.
D. Minimum wheelbase 106” maximum
110”.
F. Front bumpers must be a minimum of 1
¼” diameter x .095 wall. No “V” shapes.
G. ALL BUMPERS MUST HAVE ROUNDED ENDS WITH
NO SHARP EDGES.
H. All roll cages, bumper, and rubrails
must be round steel tubing ONLY.
I. Rear end or chassis must not be offset anymore than 4” from center at the inside tire width, measured from the inside of the left rear tire to the inside of the right rear tire, at axle height, front end the same.
J. Conventional open or closed quick-change rear end ONLY. Modified type front spindles with steel bearing shafts recommended. OPEN TUBE REAR END, STEEL OR ALUMINUM LEGAL.
K. No independent suspensions front or rear. No “A” frames or ball joints utilized for steering axis. (King pin only). All brackets on front axle must be bolted or welded.
L. Engine must be centered in chassis and placed in an upright position. Engine set back minimum 32” for small block and maximum 42”. Measured from the center of front axle to front face of block. No rear engine cars.
M. Fuel
Cell ONLY. Fuel cell height 12” minimum
from ground to bottom of tank. Fuel cell must
be fully encased in a steel container with a minimum thickness of 20-gauge. An optional aluminum container may be used with a
minimum thickness of .060”. Fuel cell
must retain foam inside. Fuel lines must
siphon from top only. Fuel tank vent line must
have an in-line one-way valve for the prevention of fuel spillage. No auxiliary tanks.
Recommended that fuel cells meet FIA/SPEC/FT-3 Specification. Integral ball check valve highly recommended for
filler neck and vent tube.
N. Only
two (2) universal joints per driveline.
O. All
suspension systems must be mechanical with no form of electrical or computer assistance. No four-wheel steering allowed that is actuated by
the steering wheel. (No cantilever suspensions or inboard shocks).
1) SPRINGS: Any form allowed.
Torsion bars, coil-overs, leaf springs, etc., provided they are made
from steel. No air ride, carbon fiber, or
titanium.
2) SHOCKS: Only one per wheel (no titanium). No shocks that
can be adjusted from cockpit. No remote wires, lines or canister.
P.
Only one (1) radiator allowed and it
must be centered in front of motor in a vertical position.
No auxiliary cooling tanks or catch cans allowed in driver’s
compartment. No plastic or carbon fiber
allowed.
Q. Seat and steering wheel must be centered in frame. HIGH BACK SEATS ONLY. NO FIBERGLASS SEATS.
4. TRANSMISSIONS: Approved North American manufactured transmission only, standard, and must bolt to bell housing, no overdrive transmission allowed. Neutral and reverse gear must be in operating order. From a neutral position with motor running, a car must be able to go forward and backward. If a conventional clutch and pressure plate are used, steel bell housing must be used.
5. MUFFLER AND EXHAUST: All cars must have approved muffler exhaust system. Exhaust may not point to ground. Schoenfeld part# 112535 is the minimum requirement. Mufflers must be securely attached. Must be welded a minimum 4 – 1 inch welds required on each muffler. NO rivets, bolts or spot welds. Only two mufflers will be allowed. Mounting positions from front to back will be optional, however, the exhaust must exit past the driver. Exhaust header manufacturers will be optional, but is limited to steel or stainless. NO crossover pipes connection the two banks of cylinders. Mufflers must be inspectable.
6. BRAKES: All cars must have four (4) hydraulic brakes in good working condition. No carbon fiber rotors or pads. (Foot brake is mandatory).
7. WHEELS: Steel or Aluminum wheels only. Beadlocks are allowed. Rim width to a maximum of 14” only.
8. TIRES: American Racer Spec Tire Rule stamped Mercer:
LF: 26/10.5-15DTSH, 11x84”, SD33 or harder
RF: 26/10.5-15DT, 11x85”, SD33 or harder
LR: 27.5/11.0-15DTW, 13x87”, SD33 or harder
RR: 29.0/11.0-15DTW, 13x92”, SD44/38/33 or harder
Notes: No tire softener or any liquids
will be allowed inside or outside of tires. Heating of tires by torch, blankets, or
exhaust system is not allowed. Any form of tampering with the tires such as
above-mentioned will result in complete disqualification.
9. WEIGHT: 2400 lbs. Open 358 after the
race with the driver in the car.
2300 lbs. DIRT Sportsman 358 with 2-barrel carburetor and inline 6 cylinders after the
race with the driver in the car.
Notes:
All bolt-on weight must be securely fastened to frame rails or chassis
tubing. No front or rear bumper mounts or body mounted weight permitted. No weight mounted
behind driver’s head.
10. MISC: NO mirrors or reflecting devices. NO radios
MANDATORY SAFETY RULES
1.
All cars are subject to inspection at
any time and must be free from mechanical defects and be in safe racing condition.
2.
Driver’s seat must be securely
fastened to frame or cage 3/8" bolts minimum. It is recommended that seats mounted
over drivelines have a minimum 1/8" steel plate under and up the back 4" and be
as wide as seat.
3.
Driveshaft cover is mandatory. All
cars with open driveshafts must have a tunnel, minimum of 1/8" thick steel from
2" under front edge of seat to back of transmission covering shaft and "U"
joint on top and both sides down to floorboards. It must be held in place with a minimum
of 4 (four) 3/8" bolts at bottom to a substantial cross-member. This drive shaft
cover must be a solid unit with no cutaways for lightening purposes.
4.
NOTE: Closed drive type cars, torque
tubes, or bells that already have a 360o covering from "U" joint back
to seat will be accepted as is. It is recommended that any car that has a suspension link
such as a torque arm, coil over or trailer bar in the driver’s compartment, have a
steel cable (1/4" in die. or more) or clamp around it limiting its range should it
break loose from its mount. It is also recommended to have these parts free of sharp edges
and padded.
5.
Mandatory functional padded headrest
must be in line with center of driver’s head.
6.
All cars must have 4 (four) wheel
hydraulic brakes, all in good working order. Steel rotors only.
7.
Belly pan must extend from rear motor
plate to rear of seat.
8.
9.
Fuel lines, power steering lines, and
fittings running through driver’s compartment must be of approved type. (Braided
lines recommended.) NO CAST IRON FITTINGS.
10.
Exhaust headers must be safe for
driver and recommended to exit past driver’s seat.
11.
Firewalls, both front and rear are
mandatory. The rear firewall must extend from top of fuel cell to belly pan. Minimum
.050" thick aluminum or steel only. A minimum amount of sheet metal may be cut out
for drive shaft clearance. The front firewall must isolate driver from the engine
compartment.
North American passenger car V-8 engines and inline 6 cylinders with cast iron block. NO 4-cylinder or V-6 engines allowed
All engine parts MUST have casting or part numbers on them for identification.
Engine
Max cu. in.
Chevy small-block
361 cu. in.
Chrysler small-block
365 cu. in.
Ford small-block
362 cu. in.
Any make inline 6 cylinder 360cu. in.
1. BLOCKS:
Steel block only. Aftermarket blocks permitted.
2. A. OPEN 358 CYLINDER HEADS: Any
aluminum or steel head permitted, providing it maintains OEM valve angles for engine make
and block used (wedge type engines only). Inline valves only. NO canted valve heads
permitted. No hemi heads permitted. No
18-degree or SB-2 type GM heads allowed. Cylinder Heads must be manufactured for engine
block used, i.e. Chevy to Chevy, Chrysler to Chrysler, or Ford to Ford.
B. 2300 lbs CAST IRON NON PORTED CYLINDER HEADS: 358 DIRT Sportsman-legal non-ported with 2-barrel only. Will be determined by the 2006 DIRT Motorsports rule book.
3. CRANKSHAFT: Any steel or cast iron
crankshaft is allowed. NO titanium or exotic metals.
4. RODS: OEM stock production or after
market rods are allowed. No titanium or aluminum. Rod length will be optional.
5. PISTONS: Any brand, 3-ring aluminum
pistons.
6. VIBRATION DAMPENERS: Any vibration
dampener is permitted. Fluid dampeners are allowed.
7. CAMSHAFT: Any make hydraulic, flat
tappet or roller cam allowed.
8. INTAKE MANIFOLD: One 4-barrel intake
manifold permitted
9. CARBURETOR: Engine limited to one
American manufactured carburetor not to exceed 4 venturii. No in-line venturii. No fuel or
air shall enter by any means other than stock operation of carburetor. Fuel injection,
super chargers, or mechanical turbo chargers are not legal.
10. IGNITION:
Any kind of ignition mechanically driven in stock position. No crank-trigger ignition
systems. Only one spark plug per cylinder.
11. LUBRICATION
SYSTEM: Any permitted. Oil coolers will be permitted providing they are mounted under the
left wing or under the hood only. Oil pan must
have 1” plug in side of oil pan to inspect rods.
12. WATER
PUMPS: Cast iron or aluminum.
13. FUEL
PUMPS: Mechanical driven only. No electric
fuel pumps are allowed.
14. FUEL:
Gasoline or methanol legal. No additives or nitrous oxide. (
1. SEALING
PREPARATION: Drill 4 front intake manifold bolts through head with 1/8” drill size
for engine seals to be installed after pump procedure. Sealed engine may be torn down at
anytime at discretion of tech inspector or
2. PUMPING
& TEARDOWN PROCEDURE: Any car may be pumped at anytime, hot or cold, at the discretion
of track owner or tech inspector. The tech inspector will determine which cylinder or
cylinders are to be pumped.
3. Each
week the winner and two other finishers (randomly chosen with the finishing positions
posted on the blackboard when the green flag waves in the feature) will be tech inspected,
and any other car(s) that track owner or tech inspector requests.
Tech
Inspector: Randy Myers 814-432-2461 (days) or 814-432-5175 (evenings)
RULE BOOK
DISCLAIMER
The rules
and/or regulations set forth herein are designed to provide for the orderly conduct of
racing events and to establish minimum acceptable requirements for such events. These rules shall govern the condition of all
events, and, by participating in these events, all participants are deemed to have
complied with these rules. No expressed or
implied warranty of safety shall result from the publication of or compliance with these
rules and/or regulations. They are
intended as a guide for the conduct of the sport and in no way a guarantee against injury
or death to a participant, spectator, or official.
The race
director shall be empowered to permit reasonable and appropriate deviation from any of the
specifications herein or impose any further restrictions that in his opinion do not alter
the minimum acceptable requirements. No expressed
or implied warranty of safety shall results from such alterations of specifications. Any interpretation or deviation of these rules is
left to the discretion of the officials. Their
decision is final.
On occasion when situations arise
that are not covered by written rules, special rulings may be put into effect by the track
officials. Once such rulings are acted upon,
they become an act of policy and will be added to the existing rules of procedures.
The Management
of