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2008 Dillon Motor Speedway
Chargers/Modified

COMPETING MODELS

  1. 1970-2008  rear wheel drive cars with a minimum wheelbase of 104” Wheelbase.  

CAR BODIES

  1. All cars must have a minimum of (2) doors, (2) rear quarter panels, deck lid, back bumper cover, roof and hood.
  2. All bodies must meet roof and spoiler height template specifications.
  3. All bodies must be approved by speedway.
  4. All cars must be painted and lettered professionally. 
  5. Rocker panels may be fabricated but must maintain 4” ground clearance.  
  6. Front windshields must be lexan. Back window optional. Clear lexan or plexiglass may be installed in the rear quarter windows. No side windows.
  7. ¼” mesh screen required if no windows.
  8. Speedway approved window net must be installed in the driver’s side window opening. 
  9. Body height minimum 4 inches.
  10. Rear spoiler 5” high with maximum 60” width or no wider than the deck lid.  
  11. Wrecker hookup required font and rear of car.

FRAME

  1. Stock OEM front sub frame with tubing frame connector mandatory.
  2. Frame must be OEM stock for weight break. Rear trailing arm mounts may be fabricated.
  3. Fabricated chassis allowed with a 100 lb. weight penalty. Frame rails minimum 2”x 3”. 
  4. Chassis rails must maintain 5” ground clearance with driver.
  5. A Steel firewall must separate the driver from the engine compartment and fuel tank.

ROLL CAGE

  1. A complete speedway approved roll cage.
  2. Roll cage must be constructed of roll bar tubing with a minimum outside diameter of one and half 1 ½” inches x .083 wall thickness.
  3. Roll cage must be centered on the frame. Perimeter style. Grandfather rule in place
  4. Main roll cage uprights must be on top of outside frame rails.
  5. Full cage is required with four uprights and four top bars.
  6. Roll bars may go through front and rear firewalls.
  7. Minimum of four bars in driver’s and passenger’s door required.
  8. All bars within drivers reach must be padded.

SUSPENSION

  1. Adjustable cups allowed on front and rear.
  2. Spring spacers or screw jacks may be used on front and rear.
  3. All cars must be equipped with OEM type steering box.
  4. OEM stock spindles required.
  5. Lower A-frames must be OEM Design.
  6. Upper A-frames may be fabricated.
  7. Front sway bar may be OEM or aftermarket. Mounting points may be aftermarket.
  8. Leaf spring and/or coil spring suspension allowed.
  9. Steel rear lower trailing arms required.
  10. A fabricated metal top link and track bar allowed.
  11. Damper shocks may be used.
  12. Rubber bushing, metal bushing, Teflon bushings or heim joints allowed.
  13. Lowering blocks and trailing arms may be adjustable.
  14. Aftermarket close 5 hubs required.

REAR END

  1. Rear end may be car, truck, or floater. No quick change. Any ratio.  
  2. Detroit Locker, posi-traction, or locked rear end only.

SPRINGS and SHOCKS

  1. Tie rod or spherical end shocks allowed. OEM aftermarket Struts allowed.
  2. Aftermarket steel welded body shocks allowed. No canister shocks allowed.  Aftermarket coil springs minimum diameter 5”.
  3. No composite leaf springs. Coil over eliminator allowed on rear.

BRAKES

  1. Single piston steel OEM stock brake calipers required. All 4 wheels must work.
  2. Steel disc brakes may be used on front and rear.
  3. Aftermarket brake and clutch pedal allowed.
  4. Dual master cylinder allowed. Brake bias adjusters allowed but not in drivers reach.

WHEELBASE and TREADWIDTH

  1. 104” minimum wheelbase.
  2.  Cars must not exceed the maximum allowable tread width of 66 inches.


CRATE ENGINE chev#88958602, chev#88958603, dodge#5007949

  1. This Crate engine can be used as all supplied parts from factory manufacturer with a speedway seal on engine.
  2. Crate engines are designed to cut the cost of racing. Anyone found tampering with these engines will be fined up to $1000.00 for each offense and loss of points.


ENGINE

  1. Only stock production engines allowed. Chevrolet 350 cubic inch maximum, Ford 351 cubic inch, Chrysler 360 cubic inch plus overbore.
    1. (Chevrolet 400 OEM stock engine allowed but must have OEM crankshaft externally balanced, OEM stock factory rods only).
  2. No polishing or coating inside of block.
  3. Overbore of .060 permitted. 
  4. Aftermarket stock length replacement rods allowed.
  5. Only solid steel connecting rods permitted. No polishing or machine work will be permitted. Replacement rods may not be lighter than OEM stock rods.
  6. Connecting rods must be stock length for make and model of engine used. 
  7. Flat top or dish 3 ring pistons permitted. Piston must not extend above top of block.
  8. Crankshaft with stock stroke must be retained..
  9. Crankshaft must not be Knife-edged. No excessive machining or grinding other than balancing. Subject to inspection by tech official.
  10. Wet sump oil system only.
  11. Enlarged oil pan allowed. Kick outs will not be permitted between the bolt holes flange and the top of the added sump. Oil pan 4” minimum ground clearance.
  12. No electric fuel pumps allowed.
  13. Aftermarket valve covers allowed.
  14. Aftermarket pulleys allowed.

HEADS

  1. Stock OEM production steel heads only. 
  2. NO modifications, no porting, polishing, or angle milling. No grinding of any kind. 3 angle valve job ok as per Speedway rule. One cut below valve seat, to bottom of valve guide. Do not radius or blend bottom of cut below valve seat.
  3. Chevrolet 70cc minimum; Ford (Clev) 68cc; Ford (Win) 58cc; Chrysler 68cc minimum.  
  4. OEM valve size for cylinder head required. Steel valves required.

CAM SHAFT

  1. Hydraulic or flat tappet cam and OEM diameter lifters with a maximum lift of Chev .480, Ford .512 Dodge .500 at valve with valve lash as ran in race. Lift will be measured at the retainer.
  2. Any steel type timing chain allowed.
  3. OEM diameter valve springs and steel retainers required.
  4. Screw in studs and guide plates permitted with any ratio roller rocker arms allowed.
  5. Stud girdles are permitted. Poly lock allowed.

INTAKE and SPACER

  1. Cast Iron two barrel intake or Edelbrock performer aluminum intakes. Chevrolet #2101 Ford Windsor #2181, Cleveland #2665, #2750 and Chrysler  #2176 or P#4532852.
  2. No high performance intake manifolds permitted. Intakes must be speedway approved.
  3. No porting, polishing, or grinding will be permitted. Do not touch it.
  4. Rochester spacer a maximum 1” single metal spacer with 1 or 2 holes centered in spacer with a straight cut.  No Bevels. Spacer Gaskets .065 max thickness.
  5. Holley #7448 spacer a maximum ¾” metal spacer with 2 holes centered in spacer with a straight cut. No Bevels. Spacer Gaskets .065 max thickness.
  6. All carburetors and spacer plates must meet speedway specifications.

 

CARBURETOR

  1. OEM stock two barrel Rochester 2v with a maximum of 1 11/16” throttle bore.
  2.  Holley 2300 2bbl carburetor model #7448 “350”.
    1. 1 ¼” (1.250) restrictor plate centered required on Rochester carburetors.
    2. GM #88958602 Crate engine Holley #7448 mandatory.

 See below for rework guidelines:

  1. No polishing, grinding or machine work allowed on any part of carburetor.
  2. No alterations except choke hardware may be removed and all vacuum ports must be plugged. Base plate must not be altered in shape or size.
  3. Boosters may not be altered in any manner including size, shape or height of model #.
  4. Any attempt to pull outside air other than through the venturi is not permitted.
  5. Holley jets allowed.

AIR CLEANER

  1. Round air cleaner element minimum of 12 inches; maximum of 17 inches. 
  2. Element must be minimum of 1 ½ “and a maximum of 4 inches in height.
  3. Dry type paper element only. No cold air boxes or cowl induction allowed.
  4. No tubes, funnels or anything which may control the flow of air are permitted.
  5. Air cleaner base must not be above choke horn. 


TRANSMISSION and FLYWHEEL ASSEMBLY

  1. OEM standard production Automatic, Manual transmissions permitted.  
  2. Heavy duty OEM steel clutch permitted. No lightening.
  3. “Built Engine” minimum clutch and flywheel assembly with bolts 35 pounds.
  4. “Crate Engine” minimum clutch and flywheel assembly with bolts 33 pounds. 
  5. Hydraulic clutch control permitted.
  6. Must have speedway approved scatter shield or steel bell housing.
  7. Drive shaft must be of magnetic steel only. Drive shaft must be painted white with two safety loops attached to the bottom of car.

EXHAUST

  1. Headers will be permitted. Header wrap allowed.
  2. OEM stock cast iron manifolds permitted.
  3. All exhaust must exit behind the driver.

ENGINE LOCATION

  1. Engines may be interchanged from one body manufacturer to another.
  2. Engine must be centered in chassis. #1 spark plug in line with upper ball joint.
  3. Minimum crankshaft height is 12”, from the center of crank pulley to the ground.

COOLING SYSTEM

  1. Aluminum radiators permitted. Any radiator allowed.
  2. All cars must have an overflow hose to the rear of the race car.
  3. Antifreeze is not permitted.

ELECTRICAL SYSTEM

  1. Electronic or point type OEM ignition allowed.
  2. No aftermarket distributors permitted.
  3. Only 1 racing coil permitted. (Accell, MSD, etc).
  4. Only one 12-volt battery permitted.
  5. No MSD ignition box allowed. No adjustable timing controls.
  6. No open ended wiring in driver’s compartment.
  7. Any type traction devices are not allowed. No computerized systems are allowed.
  8. All ignition systems must be acceptable to speedway officials.

FUEL and FUEL SYSTEM

  1. Track fuel required. No other mixtures of any kind.
  2. All Fuel must pass Speedway Fuel specifications.
  3. Fuel cells are recommended. Must be securely strapped down with no less than 1/8” steel straps. Fuel cell must be vented high and to the left side.
  4. The maximum capacity allowed is 22 gallons.
  5. Fuel cells must have 8” minimum ground clearance.

WHEELS and TIRES

  1. Maximum width 10”on all 4. 15” Steel wheels only.  
  2. Air bleeders will not be permitted. No chemical tire treatment allowed.
  3. Tires used for qualifying and race must be approved by the speedway.
  4. Any car tires from any source other than speedway supplier will be disqualified.
  5. BF Goodrich Branded Track Tire required. Compound B+ - Right, LH – Left.

WEIGHT

  1. 3250 lbs. minimum weight with driver
  2. 55% left side maximum weight percentage.
  3. Crate engine GM #88958602  equipped receives 100 lb. weight break.
  4. Fabricated chassis must add 100 lbs to total weight.
  5. All cars will be weighed with driver in a driving position.
  6. All lead weight must be added to chassis securely.
  7. Cars may gas up after race.
  8. No tungsten allowed.

AMMENDMENTS

  1. These rules are subject to amendments for competition when ample notice has been given by the speedway. Any car that does not conform to the above rules may be allowed to compete with a weight and/or restrictor plate at the tech committee’s discretion.
  2. Speedway officials may use professional judgment for any infractions for a competitive race program.

 

****ANY RULES YOU DO NOT UNDERSTAND, PLEASE CONTACT SPEEDWAY OFFICALS FOR CLARIFICATION.