Section 7
2008 358-Modified Division
2008 D.I.R.T. Rules Apply
Provisions are included to allow
DIRT-Sanctioned 358-engines
that
fit 2005 specifications.
Read Sections 1-4 first as they apply to this class
~One way radios mandatory~
These rules are mandatory and will be strictly enforced.
Cars must weigh 2450 lbs. after competition with driver; no lubricants or
fluids added.
All cars are subject to inspection at any time. All cars must be free from
mechanical defects and be in safe racing condition. Track or Series officials
decision regarding any safety infractions will be final.
All engine sizes and car weights must be clearly displayed on the hood of the car.
1. - MANDATORY SAFETY RULES FOR 358 Modifieds.
Only round steel roll over bars may be used. Front
and rear roll bars must be connected at top in a cage type configuration. Two
round horizontal side bars on each side are mandatory. The top side bar must be
a maximum of 20 below the top roll bar. Proper bracing and triangulation on
front and rear roll bars is required. It is highly recommended that all roll
bar bracing be a minimum of 1 1/2 diameter by .095 wall thickness. A minimum
of one diagonal bar across the top of the roll cage is mandatory.
The rear main roll bar hoop must be a minimum of 26 measured across from
outside to outside of tubing and must maintain that measurement from the bottom
all the way to the top of the cage. Bottom of the rear roll bar must be welded
to the 2 x 4 frame (no outriggers). The front roll bar must be measured and
constructed the same way, except that the allowable taper in the frame rules
will govern the width dimension Only two roll bar
diameters will be allowed. Roll bars of 1 3/4 diameter will require a minimum
of .095 wall thickness. Roll bars of 1 1/2 diameter will require .120 wall
thickness.
A minimum clearance of 1 ½ is required between the top of the normally seated drivers helmet and the underside of the horizontal roll cage bars.
Shock resistant roll bar padding must fully cover all bars that that may come in contact with the drivers head while strapped in the seat. On center type steering, all housings, lines, and fittings must be covered with shock resistant roll bar padding. The steering wheel center must also be padded. The starter housing and any other points of contact that could potentially injure the driver must also be adequately padded. It is recommended that this padding is flame retardant.
Drivers seat must be securely fastened to frame
or cage in six spots, with a minimum of six (6) 3/8 bolts, four (4) on bottom
and two (2) on the seat back. All seats must have a minimum 1/8 steel plate
under and up the back 4 and be as wide as seat. The seat must be one piece
high back type only. The seat must be made of aluminum only (no fiberglass).
Seat and steering must be centered in frame.
All cars must have a functional padded head rest which must be in line with
center of drivers head, if not built into the seat.
All cars must be equipped with 5 point seat belts to SFI 16.1 specifications. All belts must be securely fastened to the frame or cage. Bolts may not be inserted through webbing for mounting. The sternum shoulder harness is highly recommended.
Seat belt webbing that comes into contact with any sharp or unradiused metal edge must be protected from that edge by means of push on grip vinyl trim. The areas of concern are the webbing slots in the metal racing seats. All the seat manufacturers either roll the edge or supply the seat with trim protecting the webbing from abrasion or cutting under impact conditions. Webbing entry slots into the seat with an existing metal roll of 1/8 inch smooth radius will not require vinyl trim.
The areas where the webbing slot has been enlarged by filing or cutting are of particular concern. In most instances the edges have been left sharp, increasing the incidence of belt failure. As racing seat belts are subjected to severe conditions, it is encouraged that worn/frayed belts are replaced immediately and undamaged belts are replaced every 24 months. The date sewn into the webbing should be used as a guide. Where the seat belt date is known to be new old stock, it is acceptable practice to extend the replacement date on that set of belts to 36 months from date of manufacture. Belts older than 48 months will not be allowed for the 2005 season. Damaged belts will also not be allowed.
All drivers must wear a 2000 or newer SNELL approved full face helmet and clean one piece SFI drivers suit, quilted or with underwear, head socks, gloves, foot socks and shoes to SFI specification 3.2a and 3.3. Note: The following items are highly recommended: Arm restraints and a neck brace.
All cars must have a full steel wind screen of substantial material with a maximum individual hole opening of 2 by 1 by 1/16 (no chicken wire or aluminum). Screen must cover entire windshield area left to right across the cage and from top of cage down to hood or cowl. Clear lexan or safety glass windshields may be used for additional protection if they are in the drivers line of sight. They must be shatterproof and mounted behind the screen enabling driver to wipe them clean. Any additional windshield must not obstruct the emergency exit of the driver.
Adequate window openings on both sides of the car must be maintained for emergency exit of the driver. The minimum opening size is that which will allow a rectangular box with dimensions of 12 high by 18 wide by 30 long to be passed through the inside of the car from one window through to the other side. Any obstacles other than the drivers head rest, which prohibit the passage of the inspection box through the cockpit, must be removed.
All cars must have a drive shaft cover. All cars
with open drive shafts must have a tunnel, made from a minimum of 1/8 thick
steel which extends from 2 under front edge of seat to the back of the
transmission, covering the shaft and U joint, and output flange on top and
both sides. It must extend completely down to floorboards. It must be held in
place with a minimum of four (4) 3/8 diameter bolts at bottom connected to a substantial
cross-member. This drive shaft cover must be a solid unit with no cut-aways for lightening purposes.
Two steel safety rings diameter to suite x Ό wall thickness x 2 long, each
fastened by two 3/8 grade 5 bolts to the torque arm side plates or the frame
must be installed around each universal joint.
NOTE: Closed drive type cars, torque tubes, or bells that already have a 360
degree covering from U joint back to seat will be accepted as is. To protect
the driver, any suspension link such as a torque arm, coil over or trailer bar
inside the drivers compartment must have a steel cable (1/4 in diameter or
more) or clamp connecting it to a substantial cross-member to limit its range
should it break loose. It is also recommended that all these parts have no
sharp edges and are padded.
Firewalls, both front and rear are mandatory. The
rear firewall must extend from top of fuel cell to belly pan to isolate the
driver from the fuels cell. Minimum .050 thick aluminum or
steel only. A minimal amount of sheet metal may be cut out for drive
shaft clearance. The front firewall must isolate driver from the engine
compartment
.
Belly pans are mandatory and must extend from front firewall to rear firewall
and be attached at both spots. It is mandatory to have a separate floor to
protect the drivers feet in the event the under pan falls off. This extra
floor must be attached to the frame or cross-member or both, and extend from
the front firewall past front of edge of the seat.
All crews must carry an operable fire extinguisher of 20 pound marked with the
number in 2 inch numbers/letters in the rear of their transporter s, capable of
extinguishing gas and oil fires. On board flame-out systems fitted in the
race car are recommended.
. .
All cars must have an ignition switch which is easily accessible within the drivers compartment. The ignition switch MUST be marked ON/OFF with a bright colored paint and be clearly visible and easily accessible to the safety crew.
A fuel shut-off valve must be mounted within easy reach of the driver and the safety crew. It must be labeled in a clearly visible location with words FUEL ON/OFF with a bright colored paint.
Fuel lines, power steering lines, and fittings running through the drivers compartment must be of made from an approved braided type line only. No plastic or glass fuel filters allowed. High pressure lines and fittings or hot fluid lines running through the drivers compartment must be encased or shielded by a deflector to prevent driver injury.
All cars must have four (4) wheel hydraulic brakes in good working order. Brake tests may be held throughout the year.
Rear wheels must have a minimum of five (5) lug nuts. A minimum of three (3) lug nuts is required on front wheels only. No Knock off hubs on any wheel are allowed.
A fuel cell with a maximum capacity of 24.5
Length - 1/2" x Width- 1/2" x Depth - 1/2" = no more than 5660CI
Tank panels may not be bowed out or bellied to increase capacity. No tolerance.
Tanks may not be altered in any way so as to increase capacity.
No large and or long fuel lines, oversize filter housings or fuel coolers or
other to increase fuel capacity.
Cars teched before the event will have the
opportunity to correct any fuel capacity infraction. Cars found with illegal
fuel capacity after an event will be disqualified (dq)
and placed last in that event. All legal cars will move up in position for both
points and prize money.
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. The cell must
be fully foamed with just a minimal cut-out for filler. Cut-out may be no
larger than 6 wide by 10 long by 7 deep. Fuel lines must siphon from the top
only. There must be a one-way safety valve in the vent line. Fuel tank must be
mounted behind driver. Fuel tank must be secured by at least two steel straps
(each strap must be a minimum of 1 wide) and bolted with at least 5/16
diameter grade five (3 line) bolts.
Fuel cells should be to SFI 28.1/.2 or FT3. No fuel cell bladders may be older
than 5 yrs from date of manufacture.
A horizontal bar with minimum dimensions of 1 by .095 wall thickness must be mounted behind the fuel cell for rear impact protection.
Exhaust headers must be safe for the driver and
exit past the drivers seat. NOTE: all exhaust pipes must exit facing the rear
of the car and be directed in such a way as to disturb as little dust as
possible. Pipes may not exit through the doors or in front of the rear tires.
No mirrors or reflecting devices allowed.
Inspectors reserve the right to request body or sheet metal to be replaced and painted if it has any sharp edges or is not looking presentable to the sport.
A minimum of two (2) throttle return springs and a steel toe loop on gas pedal are required.
No racing fuel in drums may be brought on to track premises.
No oil cooler may be mounted external to the body work. . All oil cooler piping shall be routed under the body work, as safely away from driver as practical.
A) Oil coolers may be no further forward than the center line of the rear axle. It is recommended that the cooler be horizontal, flush with a cut out in the deck.
B) Oil coolers with a duct covering them on both sides and the rear may be mounted further forward than the center line of the rear axle.
C) Oil coolers may be mounted under the hood ahead of the motor.
Max rear spoiler height, irregardless of ride height not to exceed 50. This height will be randomly measured during an event. Cars not complying will be excluded. It is suggested that manufactures do not make tall cars, that can only pass tech at low ride heights. Following race car driver must be able to see through for clear view of track ahead.
2. 358 STYLE BODY-
ALL MEASUREMENTS MAY BE TAKEN WITH OR WITHOUT DRIVER AND OR WITH OR WITH OUT
FUEL.
BODY MATERIAL ALLOWED:
-Only aluminum or steel will be allowed for all inner and outer body panels. A maximum of 4 vertical plastic material extending below the metal body panel is permitted. The plastic thickness shall be between 0.090 and 0.125 and an overlap of 2 to secure to the doors/door extensions will be permitted. The overall dimensions of the doors and door extensions must meet the specifications. The roof must be fiberglass only. Hood, hood scoop, windshield cowl, right rear inside tire clearance cover and front spoiler may be constructed of either fiberglass or aluminum. Only clear lexan will be allowed for the rear spoiler and the rear wing windows.
-Tolerance permitted on all body dimensions is maximum ½. This is a tolerance not a dimension to be added to the body dimensions
ROOFS:
Roof must be centered from side to side on roll cage and also be centered on frame (No offset bodies). Leading edge of roof must be fastened in a stationary position a minimum of 33 and a maximum of 48 in front of rear axle centerline. The roof must be securely fastened at the back and on both ends.
Length of roof: maximum 60, minimum 48. Width of roof: maximum 52, minimum 48. Must display a turtleback style and shape with at least 3/4 belly front to rear and 1 1/4side to side. The roof contour must fit DIRTs roof template patterns left to right and front to back (NO FLAT ROOFS). Front lip may not be more than ½. Side edges may be no greater than 1 break. See drawing xyz.
Roofs cannot change shape or location while racing.
Overall height (top of highest point): minimum
52, maximum 61, measured from the ground. Maximum roof angle is 5 degrees on
the old DIRT gauge (This is 8 ½ deg on a mean line) with no deflections in roof
contour. See drawing abc.
All roofs must be one piece fiberglass only and be a single ply, one contour
inside and out. No carbon fiber. Roll bars must be exposed from any angle. No
vertical metal used to mount roofs will be allowed covering the roll bars. Roof
must be a minimum of ten pounds.
FRONT DOOR POSTS:
Door posts must be 2 wide x 3/8 from the side view from the roof all the way down to the door. The posts must be flat, no angle shape or round tubing will be permitted. No lexan vent windows or excessive sheet metal will be allowed in the vent corner where the post meets the door panel. Posts must be made from folded metal of minimum 0.050 and maximum 0.090. Strictly no solid door posts permitted. Door posts shall attach securely to metal roof structure.
REAR WING WINDOWS:
All rear wing panels and windows must resemble a current OEM body style. Their upper profile may not protrude above a straight line drawn from the rear of the roof to a point 2 below the top of the rear spoiler or 3 high at the rear. There must be at least a 2 ½ indent in the profile, so as not to make this panel a fast back. The maximum base length must not exceed 61. Left and right must be of the same style. See example of Body Style Diagrams pqr. The name of the body style picked must match the wing window design and be lettered as such on the front center of the roof. All window styles must be, at least 10tall x 16long, clear, smooth lexan with no bends or breaks. No writing or decals allowed on the wing windows.
Rear view of the wing window must go in a straight line from top of quarter panel or body line to the roof with a maximum gradual deflection of 2 in the center of wing window. Side view of the rear wing window must extend from the roof to the rear top of quarter panel in a straight line or in accordance with the window style chosen. A maximum of 3 higher than the rear deck height at that point will be allowed. Reference the Modified Body Diagram stu for specific details.
DIAGRAM OF 358
-SIDE VIEW
__INSERT DIAGRAM__
DIAGRAM OF 358
-REAR VIEW
__INSERT DIAGRAM__
DIAGRAM pqr MANDATORY BODY STYLES
__INSERT DIAGRAM__
BODY WIDTH AND GROUND CLEARANCE:
Body width (measured anywhere along the body line, front or back): 68 maximum, 64 minimum. Minimum body and chassis ground clearance 2 1/2. No fan or ground effects cars. No rubber skirts, fins, or spoilers of any description are permitted under the car. A 2 max air deflector is permitted in front of radiator to facilitate cooling.
DOOR PANELS
Side door panel: minimum 60, maximum 70 in front of centerline of the rear axle. Doors must be straight up and down within that measurement. Front door extensions will be allowed up to 20 behind the front axle centerline. Front door height must be a maximum of 38 and minimum of 30 from the ground measured at 60 from rear axle centerline. Ground clearance on the bottom of the doors must be a minimum of 6 and a maximum of 12 from the ground. All doors and rear quarter panels may have a maximum lip of 1 1/2 rounded at 90 degrees and facing inward only, on the top and the bottom. At the top of the doors and rear quarter panels, A lip angled out at a maximum of 45 deg., Protruding away from the door no more than ½ and no more than 1 in length before it bends inward for strength will be allowed.
REAR QUARTER PANELS
Rear quarter panels must match each other. They must be a maximum of 45 and a minimum of 40 from the ground at the rear and continue in a straight line with top of door (see Modified Body Diagram def). You may use a fender flare, up to a maximum of 2 from the body but overall body width must still be maintained at a 68 maximum. Rear quarter panels can extend back to 48 maximum at top and may incline down to 44 maximum at bottom measured from center of rear axle to rear of car. Ground clearance on rear quarter panels must be a minimum of 8 and a maximum of 16.
REAR SPOILER
The rear spoiler must be clear lexan with a maximum height of 5 from the rear deck and must not have any writing or stickers on it. The rear spoiler must be non-adjustable (no hinges or slides). No metal Gurney tabs permitted. Lexan may be pleated for rigidity.
Spoiler maximum height from ground is not to exceed 50.
A maximum of four vertical supports may be used to fasten the spoiler to the rear deck. These supports may not exceed 2 in vertical height and 10 in length.
REAR DECK
Must be a maximum height of 47
and minimum of 40 from the ground.
Rear deck lid (i.e. trunk lid) must be fully enclosed from quarter panel to
quarter panel and have a minimum height of 9 and a maximum of 14 in vertical
coverage behind the fuel tank. Left and right rear trunk lids must be
symmetrical in size and shape and show no specific bulge or extension to cover
fuel filler hose or apparatus within the 9 to 14 of vertical coverage. This
panel must completely cover the fuel cell, filler hoses, and vent lines. The
fuel tank must be completely enclosed from the bottom of this panel to the
bottom of the fuel cell.
The fuel cell must also have both sides completely covered by sheet metal in addition to the container it is enclosed in. Within these dimensions there can be no openings. No openings from top of fuel cell to bottom of trunk lid are permitted.
Any vent line nozzle used for catch can purposes must be mounted on the left side quarter panel only. No crew member will be permitted behind the car during pit stop refueling.
HOOD, NOSE, AND FRONT SPOILER
The hood, nose, and front spoiler can be no wider than 36 and no narrower than 24. The nose piece shall end at the front of the shock towers. Shock covers or deflectors may not be part of or riveted to the nose or spoiler exceeding the 36 width maximum. Fabric shock covers are allowed as long as they are used for the prevention dirt getting at shock piston and not used for any aerodynamic advantage. The front spoiler may not extend any more than 20 in front of the front axle centerline. The front spoiler must be non-adjustable (no hinges or sliders). Hood shall be considered from the front roll cage to on top and even with the front of the radiator. Nose piece shall start where hood ends to a maximum of 20 in front of front axle centerline. They all may have 2 maximum lips up or down on both sides following the contour of the body. The hood, nose, and spoiler may not overlap each others location on the frame. Any part of hood may not exceed 10 degrees nor can sheet metal have an opening or extrusion between the hood and nose. Hood must extend over the radiator and have complete sides.
2. Front windshield opening: for the optional ram air style scoop, a 8 vertical measurement from lowest point of roof or roll cage to highest point on hood (including the hood scoop) is required. For the conventional type scoop an 8 vertical measurement will be required.
HOOD SCOOP
An optional hood scoop mounted on top of the hood for the purpose of enclosing the carburetor or ram air will be allowed providing they meet the following specifications. Both style scoops may use fiberglass. The option of keeping the hood fully enclosed will also be allowed.
Ram air type scoop: Maximum length, 30 measured from rear motor plate to front of hood scoop. Maximum width 18. The front vertical opening of the scoop can be a maximum of 6 at the beginning of the scoop only. The overall height of this scoop must maintain a minimum of 10 of vertical vision for the driver. This measurement will be taken from a horizontal line from the highest point of the hood scoop to the lowest point of the front roll cage and/or roof. Hood scoop must be fastened to the hood and completely enclose the carburetor and air filter. A tolerance of 1/2 will be allowed on all these dimensions.
Conventional no ram air scoop: a maximum of 25 is allowed from center of the carburetor forward. The width allowed is a maximum of 22. The height must maintain a minimum of 8 of vertical vision from the top of the scoop to the lowest point under roof or roll cage.
INTERIOR SHEET METAL
Any horizontal body support, other than the inner
pods, whether in front or rear must be a maximum of 1 deep by 1 thick tubing
or flat stock only. No inside or outside wings, spoilers, air foils, or wind
deflectors are allowed on long or short tracks. No double panels will be
allowed that creates a wing effect. A 1 maximum reinforced lip will be
allowed on all lexan, but all allowable measurements
must still be maintained. All inner sheet metal used must completely cover
areas from door to door, quarter panel to quarter panel. No holes or openings
are allowed in this area.
No vertical fins, air dams, or fairings allowed on the sides or behind the roll cage. Sheet metal must be a flat single plane across the inside of the car. No covered roll bars for aerodynamic purposes are allowed. Sheet metal that is one-piece and part of a body panel bent around tubing (for purposes of protecting the driver or finishing off panel) is not considered an aerodynamic advantage provided it is not to excess. No louvers or holes in the interior or exterior sheet metal are permitted with the exception being the cooling of the radiator, engine, and oil cooler.
The floor pan or underpan may not be any wider than the frame, from front to back, and may not have any lips or fins facing downward.
NUMBERS
Track or series handicapper reserves the right to issue or change a cars number to prevent duplication and maintain proper records.
Team cars must be clearly distinguishable from one another and use a different number or letter.
All numbers and letters will be limited to three digits. If three digits are used, two shall be primary numbers. Numbers are required on roof, nose, rear deck and both doors.
All numbers and letters must be a minimum of 18 high on the roof and doors, and 8 high for the rear deck and nose. All numbers and letters must be of equal size and painted or decaled. If numbers 3, 6 or 9 are used make sure that they are distinguishable. Nerf bars must not block visibility of number.
3. CHASSIS SPECIFICATIONS FOR 358 Modifieds
FRAME
Only 2X4 box frames are permitted between axle centers, front and rear. The 4 side must be vertical. Frame rails must be steel only. All 2 x 4 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 rail for inspection of thickness. No other holes will be allowed. All tubing allowed for the frame rails must be either 1 1/2 dia. x .095 wall or 1 3/4 x .095 wall.
Frame width shall be as follows: Front (at shock towers): 24 minimum, 35 maximum. Rear: 26 minimum, 35 maximum. The minimum frame width at the rear roll bar must be 26. All measurements are to be taken from the outside of the frame rails. These measurements shall be taken at both top and bottom of frame at its longest length. Clips, sub-frames, etc. are considered part of the frame.
Minimum length of the 2 x 4 frame rails must start at 14 in front of rear axle centerline and extend to the front of the radiator. All kick up material must be same specifications as the roll cage or frame material. Left and right frame rails (both top and bottom rails) must be equidistant from the driveline centerline in a vertical plane along the total length of frame. The only exceptions will be the lower left rear frame rail, which will be allowed at 4 maximum indent for suspension clearance, and the two upper frame rails in the engine compartment to allow for the clearance of large cylinder heads.
Titanium or carbon fiber materials are not allowed on the chassis.
ROLL CAGE
The roll cage shall be integral with the frame. All frames built in 2005 must have a manufactures unique serial number plate prominently attached by welding on the left side front roll cage upright. The letters and or numbers shall not exceed 8 in number and be ½ in height. See drawing pqr.
All cars for 2006 will be required to have a serial number. Should the frame not be numbered, DIRT will be pleased to supply the car with a serial number plate for application by welding.
Only round steel roll over bars may be used. Front and rear roll bars must be connected at top in a cage type configuration. Two round horizontal side bars on each side are mandatory. The top side bar must be a maximum of 20 below the top roll bar. Proper bracing and triangulation on front and rear roll bars is required. It is highly recommended that all roll bar bracing be a minimum of 1 1/2 diameter by .095 wall thickness. A minimum of one diagonal bar across the top of the roll cage is mandatory.
The rear main roll bar hoop must be a minimum of 26 measured across from outside to outside of tubing and must maintain that measurement from the bottom all the way to the top of the cage. Bottom of the rear roll bar must be welded to the 2 x 4 frame (no outriggers). The front roll bar must be measured and constructed the same way, except that the allowable taper in the frame rules will govern the width dimension.
Only two roll bar diameters will be allowed. Roll bars of 1 3/4 diameter will require a minimum of .095 wall thickness. Roll bars of 1 1/2 diameter will require .120 wall thickness.
CHASSIS DIAGRAM
__INSERT DIAGRAM__
SEAT
Seat and steering wheel must be centered in the frame. The seat must be a maximum of 16 from the center of the rear end to back of seat bottom (see Body Diagram lmn). A high back seat made completely from aluminum is mandatory. No fiberglass or carbon fiber materials are permitted.
RADIATOR
Only one (1) radiator allowed and it must be centered squarely, not angled, in front of motor in a vertical position. No plastic or carbon fiber allowed. No auxiliary cooling tanks or catch cans permitted in drivers compartment.
ENGINE
The engine must be centered in the chassis and placed in an upright position. Engine set back: minimum 56, maximum 66 with 1/2 absolute maximum tolerance. Set back will be measured from the center of the front axle to the rear machined bell housing surface of the engine. No rear engine cars are allowed.
TRANSMISSION
Approved North American manufactured manual shift transmission only, no automatics. No overdrive or underdrive transmissions allowed. No running through reduction gears, transmission must be direct drive to rear end at racing speed. Transmission must have forward, neutral, and reverse gear in good working condition. From a neutral position with the motor running, a car must be able to go forward and backward in a smooth manner. Transmission must bolt to the bellhousing.
Car must have only one 12v battery (must not measure more than 14v) and a self starter in good working order The car must start and move under its own power
DRIVELINE
No chassis, driveline or suspension components made of carbon fiber allowed. Only two (2) universal joints per driveline. A drive line shield and 2 steel safety rings are mandatory (see safety rules for detailed requirements).
REAR END
6:50 Maximum Gear Ratio
Competition rears only. No hyphoid type rears allowed. No limited slip type rear ends or hubs are allowed. No lockers or two speed rears are allowed. Rear end must have solid aluminum or steel spool only. Rear spindles may be steel or aluminum only. If aluminum it must be a one-piece tube and spindle with a minimum outside diameter of 2 7/8 and maximum inside diameter of 2 1/2. Live rear ends with aluminum or steel axles are allowed. The rear end or chassis must not be offset any more than 4 from center of the inside tire width, measured from the inside of the left rear tire to the inside of the right rear tire, at axle height. (see Chassis Diagram for rear end offset details).
FRONT END
The front axle must be straight, one piece steel tubing only with no camber adjustments. No split axle or dropped axle allowed. All brackets on front the axle must be bolted or welded (no bird cages or slides). Modified type front spindles only. It is recommended that bearing shafts be made of steel. Chassis may not be offset any more than 4 from center of inside tire width, measured from the inside of the left front tire to the inside of the right front tire at axle height. (see Chassis Diagram for front end offset details). Front wheels must be fully exposed. No fenders are permitted.
WHEELBASE AND TREAD
Wheelbase: minimum 106, maximum 110. This measurement will be taken from the center of the rear axle to the center of the front axle, for both left and right sides with a maximum tolerance of 1/2.
Tread width: front - maximum 86, minimum 74. Rear tread, maximum 86, minimum 80.
CHASSIS GROUND CLEARANCE
There must be a minimum of 2 1/2 ground clearance from the chassis or anything attached to it, including any part of the body. No metal, lexan, or rubber air dams, fins, spoilers, or skirts are permitted under the car. No ground effects cars.
SUSPENSION
No independent suspensions front or rear. No A frames or ball joints may be utilized for steering axis (kingpin only). No four wheel steering allowed that is actuated by steering wheel. All suspension systems must be mechanical with no form of electrical, radio, or computer assistance. No form of traction control is permitted.
SPRINGS
Any form will be allowed (torsion bars, coil overs, leaf springs, etc.) . No carbon fiber or titanium are allowed.
SHOCKS
Only one shock per wheel.
External reservoirs are not permitted.
All shocks used MUST be freely available to all competitors. Failure to easily purchase a type of shock could result in those shocks not being permitted.
BRAKES
All cars must have four wheel hydraulic brakes in good working condition. No carbon fiber, titanium or aluminum rotors and pads are allowed. On live rear axles, one inboard and one outboard brake assembly is allowed. Brake tests may be conducted throughout the year.
Brake bias may be cockpit adjustable.
FRONT BUMPER
Must be made from round steel tubing only, with a minimum diameter of 1 1/4 by .095 wall thickness for main bumper and all bracing. It must consist of two rails, an upper and lower and at least 1 or 2 vertical braces equally spaced. These rails must have four sockets or supports attached to the frame. The four tubes that support the bumper from the four frame sockets must be horizontal. These rails must also be a minimum of 6 apart and a maximum of 12 measured from top to bottom and maintain that measurement for a minimum width of 24 or a maximum width of 30. It must also have an 18 center measured from the ground up to the middle of the bumper. The front bumper may not extend more than 24 in front of front axle center centerline.
No V-shaped bumpers, crash area must be flat and vertical for the full width of bumper. Bumper must have all rounded ends and no sharp edges and must be sloped in such a way as to prevent bumper interlocking with another cars bumper. Reference Diagram jkl
REAR BUMPER
Must be made of round steel tubing only, with a minimum diameter of 1 1/2 by .095 wall thickness for main bumper and all bracing. It must consist of two rails, an upper and lower, which must have four sockets and horizontal support bars attaching it to the frame. These rails must also be a minimum of 10 apart and a maximum of 16 measured from top to bottom and maintain that measurement for a minimum width of 64 or a maximum width of 86. The rear bumper or any side bars cannot extend past the outside of tire sidewalls on both sides. It also must have an 18 center measured from the ground up to middle of bumper. The rear bumper may not exceed 52 in back of rear axle centerline.
No V-shaped bumpers, crash area must be flat and vertical for the full width of bumper. Bumper must have all rounded ends and no sharp edges.
RUB RAILS
Must be made of round steel tubing only, with a minimum diameter of 1 1/2 by .095 wall thickness. All bracing must also be a minimum of 1 1/2 outside diameter by .095 wall thickness. Maximum wall thickness must be .095 with no solid bars or ballast added inside. Rub rails must be outside of body panels but may not exceed the outside edge of the tires. The exception is the left rub rail only, which may extend an absolute maximum of 2 outside the left rear tire sidewall.
Rub rail ends must be rounded with no sharp edges
and bent at a gradual 90 degrees and must protrude a minimum of 6 back in past
the body.
Rub rails must be a minimum of 50 long, end to end.
ALL BUMPERS AND RUB RAILS
5/16attachment bolts with nyloc nuts or DIRT approved quick release solid pins are the only permitted fasteners.
All 3 rub rail sockets must be pinned or bolted.
Front and rear sockets must have a cuff or sleeve welded to the rub rail tube to prevent pins from shearing. See Diagram mno
FUEL & FUEL TANK
One fuel cell with a maximum of 24.5
Tank panels may not be bowed out or bellied to increase capacity. No tolerance. Tanks may not be altered in any way to increase capacity. No large or long fuel lines, oversize filter housings or fuel coolers or other to increase fuel capacity.
Cars teched before the event will have the opportunity to correct any fuel capacity infraction. Cars found with illegal fuel capacity after an event will be disqualified and placed last in that event. All legal cars will move up in position for any applicable points and prize money.
Fuel tank 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 tank must be fully foamed with just a minimal cut-out for filler. Cut-out may be no more than 6 wide x 10 long x 7 deep. Fuel lines must siphon from top only. No fuel lines bigger than #10.
No auxiliary tanks. No fuel filters with more than 1/2 quart capacity.
Fuel tank vent line must have an inline one-way valve for the prevention of fuel spillage. Only one carburetor fuel log will be allowed and is limited to a maximum outside diameter of 1.
For all races that require a fuel stop, all quick fills must be located in the left rear quarter panel only. The filler tube must take the most direct route to the fuel cell. Only one filler tube is allowed with a maximum outside diameter of 3. The fuel vent line may not exceed 1 1/4 inside diameter and must go in a direct route from the fuel tank to the quarter panel. A catch can must be used with a one-way flapper valve on the left side quarter panel or the far left rear corner of the rear panel only. Catch can operator may not stand behind the rear bumper while inserting the can. Any fuel hoses or quick fills may not be visible from behind the car. They must be hidden behind the rear panel which must be symmetrical in size and shape.
MUFFLERS AND EXHAUST SYSTEM
Each car must have one muffler per bank. Mounting position front to back will be optional however the exhaust must exit past the driver. Each muffler must have a tail pipe no less than 10 long measured off the back of the muffler and must direct the exhaust to the rear of the car only so as to disturb as little dust as possible. No exhaust pipe may face outside the car.
Any manufacturer of exhaust header is allowed, but header material is limited to steel.
No cross over pipes permitted connecting the two banks of cylinders.
BALLAST WEIGHT
Any ballast weight used must be mounted within the vertical planes formed by the frame rails, must be securely fastened, and must remain stationary while racing.
Weight may be added prior to the event or time trial. No weight pack may exceed 75 pounds. All weight packs must have a minimum of two ½ securing bolts/studs of grade 5 or higher. These bolts/studs must be securely anchored to the frame by a suitable clamp. No bolts /studs welded to the frame will be permitted. Clamp around weights are permitted. All weights must be painted white and carry the car number in a legible fashion. White duct tape marked with a wide black sharpie is acceptable for a one race grace period only.
OILING SYSTEM
One oil tank, one oil cooler and one American passenger car sized battery will be the only exceptions allowed to be mounted outside the frame rails. Oil tank maximum capacity - 12 quarts.
Tank and cooler must be fully enclosed by the body and must be securely mounted. See cooler location in safety rules. Excessive bracing used for mounting these items to obtain more left side weight will be subject to the discretion of the track inspector.
WHEELS
Only aluminum wheels are allowed. No magnesium, steel, or carbon fiber is permitted. Bleed off valves are allowed.
Rim width restricted to 14 maximum. This is measured from inside of left bead to inside of right bead on the wheel. Wheel diameter limited to 15 only.
Beadlocks are allowed. Any wheel or beadlock that is used must maintain a minimum diameter of 11 hole inside beadlock and wheel. Beadlocks may be outside only, except the left rear, which may have an inside beadlock.
No wheel covers or hub caps on the inside of the wheels are allowed. Wheel covers/hub caps are allowed outside of the wheels providing they are one piece, attached as part of the beadlock and maintain a minimum thickness of .090 with a minimum hole in the middle of 4.5.
Foam inserts or corrugated plastic (with approved installation) may be allowed when track conditions warrant. No unsafe wheel covers attached by dzus buttons are allowed. Weld aluminum wheel covers are permitted.
TIRES
No tire softener or liquids of any kind is allowed inside or outside of the tires. Heating the tires by torch, blankets, or exhaust system is not allowed. No type of inner liner is allowed. Durometer readings may be taken periodically. Any tire compound allowed; maximum tire size allowed is 92-in x 13-in on a 14-in wheel (no drag rubber). Tire markings, numbers and sizes must be labeled on tire and visual at all times (subject to tech inspector approval). All tires must be readily available to all competitors. Difficulty in purchase or lack of availability may result in a tire being disqualified.
MINIMUM WEIGHTS
Cars will be weighed with the fully suited driver seated. The minimum weight permitted before and or after an event or time trial will be as measured by the track scales in the unit of track scale pounds (tsp). All cars found light before an event or time trial will be allowed to add weight. The number of top finishing cars to be weighed after an event will be announced at the drivers meeting. Those cars must be weighed before going to their pit or winners circle. Failure to weigh directly after an event will result in disqualification. Cars found light after an event or time trial, will be disqualified and placed last, scoring points and prize money accordingly.
4. 358-MODIFIED ENGINE SPECIFICATIONS
Small Block 358: (short block in length) using open Dart cylinder head - 2450 tsp.
Using Spec Brodix head, Maximum Compression 10.5 : 1 2300tsp
Black Rock Speedway reserves the right to remove, inspect,
or exchange Brodix Aluminum Spec Heads at any time
Engine rules include the 2004 DIRT MotorSports, Inc. head rules and specs. The 2005 DIRT MotorSports, Inc. head rules and specs are also admitted. Engines may be full ported as seen fit, but must remain the stock strokes as listed in the chart below. This class is reserved for North American passenger car V-8 engines with cast iron blocks and cylinder heads. All engines must maintain stock bore and stroke combinations. Normally aspirated engines only.
|
Engine |
Maximum Overbore |
|
Chevy 350 C.I. 4.00" bore x 3.480" STROKE. |
+.070 |
|
Chry. 360 C.I. 4.00" bore x 3.578" STROKE. |
+.020 |
|
Chry. 340 C.I. 4.04" bore x 3.313" STROKE. |
+.060 |
|
Ford 351 C.I. 4.00" bore x 3.500" STROKE. |
+.060 |
Engines may not pump more than 362-cubic inch
BLOCKS
OEM and cast iron performance blocks such as Chrysler (R) Block, Chevy Bow-Tie, Ford-SVO, and DART are permitted.
CYLINDER HEADS
Any cast iron stock OEM, BowTie, stock double-hump or DART 200, 215, 230 heads only (NO Vortec Heads). Must retain OEM port centers, spark plug location and all OEM angles, may be ported as seen fit, material may not be added.
DIRT-Legal Brodix Spec Head (subject to tech inspector approval); driver and car must weight 2300 pounds (DIRT rule 6.3A).
Penalty for cylinder head modifications
Up to a year suspension, loss of any point monies, contingencies.
CRANKSHAFT
Any steel or cast iron allowed providing it maintains stock stroke as manufactured for the engine block used.
RODS
OEM stock production or aftermarket solid steel are allowed. No titanium or aluminum. Maximum rod length will be 6. Engines with longer than 6 rods must meet stock OEM specs.
PISTONS
Any make 3 ring flat top aluminum pistons only.
VIBRATION DAMPENERS
May be any stock OEM or aftermarket steel or cast-iron only. No fluid or friction dampeners allowed. Must be one piece construction only. No bolts or snap-ring assemblies. Safety rings are allowed. Rubber-lined is permitted.
CAMSHAFT
Any type allowed. No overhead cams. Roller rockers, Shaft Rockers allowed. Stud girdles will be allowed. No gear or belt driven cams. Lifters must maintain stock OEM diameters. Lifter bores must remain in stock OEM positions and angles, but may be re-bushed for wear. No lash caps allowed on valves..
INTAKE MANIFOLD
Any American production as cast 4 barrel allowed (single plane aluminum only). No homemade type manifolds allowed. Part and casting numbers must remain visible and not ground off. May be ported as seen fit, no material may be added.
CARBURETOR
One 650 cfm Holley
allowed. Carburetor must maintain stock venturi and
throttle bore dimensions: primary venturi 1-1/4. The
only allowed part numbers are Holley 4777 and Holley 80777. Carburetor must
remain stock in all respects. Booster height must remain stock (no cutting or
polishing). No visible modifications without disassembly. Go/no-go gauge
measurements valid on hot or cold carburetor. Carburetor maximum height
measured from bottom of carburetor base to machined horizontal gasket surface
of block will be 7 in both front and rear of block.
CARBURETOR MODIFICATIONS ALLOWED ARE LISTED BELOW, ANY OTHER MODIFICATION NOT
MENTIONED IS NOT LEGAL. - Holes drilled in the throttle plates for proper
idling.
Drilling, tapping and plugging of unused vacuum ports. - Welding of throttle shaft to linkage arm.
Drilling of idle or high speed air correction jets.
Milling of center carburetor body metering block surface a maximum of .015 on each side.
Removal of choke plate and shaft.
The jets may be changed as needed.
IGNITION
Traction control devices are not allowed. Ignition boxes must remain as manufactured with no internal or external alterations. Wiring must remain as designed by box manufacturer. OEM firing order must be maintained.
LUBRICATION SYSTEM
No dry sump system allowed. Oil may be in steel or aluminum pan only. Oil pan must have 3/4 inspection hole for connecting rod verification on left side of pan. No external oil pumps allowed. No Accu-sumps allowed. Oil coolers are allowed.
WATER PUMPS
Pumps, pulleys and fans are optional.
FUEL PUMPS
Must remain in and be driven as stock OEM equipment. No electric pumps.
FUEL
No nitrous or any other additives. All fuels subject to random testing at each track. Note: Any infraction of the engine or fuel specifications as mentioned above will result in complete disqualification.
Disqalification
Should a competitor be in breach of the rules after the event, where this breach would improve his performance or chance of winning, that competitor will be subject to dq. Where the breach of the rules, does not improve his performance or chance of winning, then he shall be subject to the point loss and fine as laid out in the 2005 rules.
Teched cars
After a car has passed tech, it may not be altered to any specifcation that would make it illegal. Any car that carries an event tech sticker may still be subject at any stage to further tech and could face exclusion from the event.
Other
No two way radios.
Please be advised that all other rules will be applied strictly as per the 2008 rules. Please do not try and bring a car that is out of spec. You will have to do work at the track to return it to spec before being allowed to compete. Tech is required to ensure that all cars are safe and evenly matched. It is in YOUR OWN INTERESTS to prepare a legal and safe car.