2008 PARK JEFFERSON SPEEDWAY

SPECIFIC NORTHERN SPORTMOD™ RULES - 2008

No driver holding an IMCA license during the same calendar year in any other division may compete in this division, except: licensed Stock Car and Hobby Stock drivers (must still purchase SportMod™ license).
1. SAFETY EQUIPMENT: Rules apply at all times car is on track. Snell-rated SA95, SA2000 or SA2005 helmet required. Roll bar padding required in driver compartment (Fire retardant recommended). SFI-approved full fire suit required. Fire retardant neck brace, gloves and shoes required. Recommended: Fire retardant head sock and underwear; head and neck restraints; collapsible steering shaft. Driver-side window net required, minimum 16"x20" ribbon or mesh style, and must be mounted so latch is at top front of window. Minimum three-inch wide five point safety belt assembly required (Y-type shoulder harness not allowed), must be mounted securely to roll cage, recommended to be no more than one year old. Kill switch required within easy reach of driver and must be clearly marked ‘OFF’ and ‘ON’.
2. FRAME: OEM complete, 1964 or newer, perimeter American rear-wheel drive passenger car frame only. No sports car frames. Frame must be full and complete, cannot be widened or narrowed, and must be able to support roll cage on both sides, exceptions are: weight jack in original center line of spring tower allowed; frame may be cut a maximum 36 inches forward from center of rear end housing; horns may be removed in front of steering box; front crossmember may be notched and boxed for radiator and/or steering clearance; maximum seven inch wide opening in side of spring tower for spring removal. Maximum two inch wide by four inch tall frame stiffener may be welded directly to outside of left side frame rail. Minimum wheelbase 108 inches, maximum 112 inches, both sides. Maximum overall width (front or rear) shall not exceed 78 inches from outside of tire to outside of tire. For cars using OEM rear suspension design, rear of frame behind rear tires, from a point no further forward than one inch behind factory seam, may be replaced with two inch by three inch steel tubing with .095 inch wall thickness. No part of frame can be lower than four inches from ground except front crossmember.
3. ROLL CAGE: Must consist of continuous hoops, minimum 1.75 inch O.D. tubing, with a minimum wall thickness of.095 inch for main cage, frame-mounted in at least six places, low carbon or mild steel recommended. Must consist of a configuration of front, rear and top hoops connected by tubing on sides or side hoops. Driver’s head must not protrude outside cage with helmet on. Roll cage must be securely supported and braced with minimum one cross bar in top halo. Foot protection bar required. Main cage no further forward than rear of engine. All bars forward of cage must be lower than hood.
4. DOOR BARS: All driver side door bars and uprights must be minimum 1.5 inch O.D. and .083 inch wall thickness. Minimum three driver side door bars, parallel to ground and perpendicular to driver, and welded to front and rear of roll cage. Passenger side must have at least one cross door bar, horizontal or angled, minimum 1.25 inch O.D. and .083 inch wall thickness, and one top door bar, minimum 1.5 inch O.D. and .083 inch wall thickness. Steel door plate, 18 gauge or .049 inch minimum thickness, must be securely welded to outside of driver side door bars and cover area from top door bar to bottom door bar and from rear hoop down-post to five inches in front of seat. Must be visible for inspection.
5. BODY: (See diagram) Must be same width, front to rear, and parallel to OEM frame. Engine compartment must remain open (no side panels). Hood must be enclosed at rear. No panel in front of right door to engine compartment. No inner panels. No car covers. Must have front windshield and rear window support posts. Driver and passenger side windows must have at least 12 inch opening (height and width), measured at center of window, between lowest point at top of window, whether roof or roll cage, and highest point at bottom of window, whether interior or body. May use Lexan in opera windows. May use full windshield. Must be fiberglass full size roof, rounded down in all directions. No wings or spoilers. No reflective doors or quarter panels.
6. DRIVER COMPARTMENT: Must have minimum three windshield bars in front of driver. Lexan or aluminum cowl panel in front of driver can be no wider than cockpit and no farther back than steering wheel. Minimum .125 inch aluminum, or .060 inch steel, complete floor pan required. Aluminum high-back seat only and must be bolted in, using minimum 0.375-inch bolts, next to left side frame rail and ahead of rear tires. Bottom of seat can be no lower than bottom of frame rail. Driver must be sealed off from track, driveline, engine, fuel cell, cannisters and pumps. Oil coolers must not protrude above interior. Accumulators cannot be mounted between driver and left-side door bars. No driver-adjustable devices allowed while car is in competition except brake adjuster. No mirrors of any kind.
7. FRONT SUSPENSION: All components must be steel, unaltered OEM, in OEM location, and replaceable by OEM parts, exceptions are: tube-type upper A-frames with or without aluminum or steel cross shaft, and mounts can be moved; OEM replacement stamped steel lower A-frames; rubber, nylon or steel lower A-frame bushings, no offset or bearing type; welded or bolted shock mount on lower A-frame. Lower A-frames must be right and left, and of same design. Lower A-frame mounts and bolt holes on frame must be in OEM location. OEM ball joints only. Sway bar must be unaltered OEM.
8. STEERING: No rack and pinion. All components must be steel, unaltered OEM, in OEM location, exceptions are: outer tie rod end and adjustment sleeve may be replaced by a minimum .625 inch steel rod end and steel tube; spindles can be ground for brake caliper clearance only; unaltered, OEM replacement Pinto spindles with ‘IMCA’raised cast; bolt on spindle savers allowed; steel steering shafts and knuckles only; steering quickener, steering wheel and quick release may be aluminum; cockpit steering may be modified, must be kept on left side. Spindles must be right and left, and of same design. Idler arm, pitman arm, and center link must match frame.
9. SHOCKS: One steel, nonadjustable, unaltered shock per wheel only. Welded shock mounts only. No coil over, air, or remote reservoir shocks. No Schrader valves or gas refill ports. Front half of any shock may be shielded. One or all shocks may be claimed per event for $50 each, counting as one claim on card, following shock claim procedures (see rule book).
10. SPRINGS: One steel coil or multi-leaf (rear) spring per wheel only. Minimum 4.5 inches O.D., non-progressive coils only. No torsion bars or air bags.
11. REAR SUSPENSION: Three options: Aftermarket three link design, multi-leaf spring design or OEM design. All components must be steel. All mounts and brackets must be welded or bolted solid. Coil springs must remain vertical and over center line of rear-end housing. No coil-over eliminators allowed. Rear shocks cannot be mounted on control arms. 1.) Aftermarket three link design requirements: Must use minimum 16 inch lower control arms. Must use one upper control arm, solid tube only, located at top center of rear end housing and remain centered on housing over drive shaft. Must use minimum 23 inch panhard bar located behind rear end housing. Lower spring perch must be welded to rear-end housing. Must use steel upper weight jack. 2.) Multi-leaf spring design requirements: Must use steel multi-leaf springs with no additional suspension components besides one shock per wheel. Adjustable aluminum lowering blocks allowed. 3.) OEM stock design requirements: Rear crossmember, control arm mounts and bolt holes on frame must be in stock location. All components must be unaltered, approved OEM, and match frame. Control arms cannot be altered in any way. Steel, rubber or nylon control arm bushings only. Springs must remain in stock location. Lower spring perch must be welded to rear-end housing. Must use steel upper weight jack.
12. REAR END: Any steel approved OEM passenger car or truck non-cambered rear end (housing and carrier) allowed, must be centered in chassis. All components must be steel, except lowering blocks, axle cap, and drive flange. Safety hubs (floater) allowed. No quick change devices. Inspection hole in housing required. Mini-spools only. Ring gear, center section and yoke cannot be lightened. Solid steel axles and one piece drive flanges only.
13. BUMPERS: (See diagram) Steel bumpers must be on front and rear at all times and welded, or mounted with minimum .375 inch bolts. Must be minimum 1.25 inch O.D. tubing, .065 wall thickness on front - .095 wall thickness on rear. Two-bar front bumper must be mounted frame-end to frame-end, no wider than width of material outside frame horns and with bottom loop parallel to ground. Top bar must be directly above bottom bar, minimum 6.5 inches apart, measured center to center.
14. TIRES/WHEELS: Must use unaltered Hoosier Race tire, G60-15 with IMCA stamped on sidewall. No softening, conditioning, siping or grooving of tires (see rule book for automatic penalties). No re-caps. All wheels must be three or four inch backspace and display white ‘IMCA approved’ decal and wheel manufacturer decal. No wheel adapters, spacers or bleeder valves. May use IMCA approved bead lock, on right rear only. External, steel bead lock only and it cannot make wheel any narrower than 8 inches and no wider than 8.75 inches. Must use only steel bolts. One foam type or plastic mud cap allowed on right rear only. Must use minimum one inch O.D. lug nuts.
15. BRAKES: Must be steel approved OEM, operative four wheel, drum or disc. Must maintain minimum OEM dimensions for hubs/rotors and calipers, cannot be lightened. Bolt pattern may be changed. Larger studs allowed. Rear rotors may be aftermarket, minimum .810 inch thickness. Vented rotors only, no scalloped rotors. One proportioning device allowed (one-to-one ratio), front to rear only. Brake lines must be visible and must connect directly from master cylinder to calipers with no devices in between. Rear caliper brackets must be welded or bolted solid to rear-end housing.
16. EXHAUST: Round tube headers only. All primary header tubes must enter directly into one collector, at same point, at end of header. Non-stepped, painted headers only. No heat wrap on headers. Schoenfeld mufflers, stamped IMCA 609, must be used if track has noise reduction rule of 98 d.b. or more. All exhaust must go through mufflers, two per car, one per header. No exhaust sensors, cross-overs or balance tubes.
17. FUEL SYSTEM: Racing fuel cell required, maximum 32 gallon capacity (12 gallon recommended), must be in minimum18 gauge steel container. Cell must be securely mounted behind rear axle, between rear tires, minimum four inches ahead of bumper, minimum ten inches above ground. Must mount with minimum two solid steel straps around entire cell, two inches wide and .125 inch thick. All cell mounts must be steel, securely welded to frame/cage. Protective tubing must cover rear and extend past both sides of cell. No part of cell shall be lower than protective tubing. Fuel cell vents, including cap vent, must have check valves. Pick-up must be on top or right side of cell. Limit of one fuel filter. No cool cans. Air cleaner top/stud cannot direct air into carburetor. No top flow air cleaner housings. Mechanical OEM type push rod fuel pumps only. Claim engine must use one of three IMCA approved naturally aspirated carburetors: OEM GM Rochester two barrel carburetor (only alterations allowed are booster I.D. may be machined to .250 inch and venturi I.D. machined to 1.375 inch); Unaltered 350 c.f.m. Holley - part no. 0-7448; Unaltered 500 c.f.m. Holley - part no. 0-4412 (both may be modified to Holley HP Dorton specs only.) Float bowl must face forward. Any adapter, maximum one inch thick. GM crate engine may use any Holley 4 barrel with or without one inch thick, one piece intake-to-carb spacer. Maximum .100 inch thick carb gaskets only. No throttle bore adjustable carb spacers. Carburetor may be exchanged, style for style only, following same procedure as engine claim. Driver claiming carburetor may not claim engine or shocks on same night.
18. FUEL: Gasoline only. Racing fuel allowed. Pump grade recommended. No performance enhancing or scented additives. Fuel must pass both dialectric meter and chemical tests. Fuel sample may be taken from any car at any time (see rule book for automatic penalties).
19. WEIGHT: Minimum weight limit of 2,500 pounds, no tolerance, after race with driver in car. Weights must not be used in driver compartment or outside body. All weights must be securely mounted with at least two .5 inch bolts, painted white with car number on it. No titanium, magnesium, stainless steel or carbon fiber components. Solid steel fasteners only.
20. BATTERY/STARTER: One 12 volt battery only, must be securely mounted between frame rails, and positive terminal must be covered. Starter must bolt on block in OEM location and directly engage flexplate/flywheel. Car must have capability of starting without being pushed or pulled. Car must leave initial staging area on demand, unaided, or go to rear of that race.
21. GAUGES/ELECTRONICS: 12 volt ignition system only. HEI distributor only. Ignition rotor, cap, coil and module must remain OEM appearing. No ignition boxes, remote coil or accessories. All wiring must be visible for inspection. Only gauges allowed are analog oil pressure, fuel pressure, brake bias, water temperature and analog tachometer (memory recall allowed). No electronic traction control devices (see rule book for automatic penalties).
22. TRANSMISSION/DRIVE SHAFT: All forward and reverse gears must be operational, plus a neutral position. With engine running and car in still position, driver must be able to engage car in gear and move forward, then backward. Only OEM production transmissions allowed. No ‘in and out’ boxes or quick change devices allowed. Functioning shift levers must be in OEM location. One steel or aluminum OEM style/size flywheel or steel OEM style/size flexplate allowed, must be bolted directly to end of crankshaft.
Automatic: Must be unaltered, two or three speed, OEM production case with a functioning OEM appearing pump. Aluminum OEM bellhousing may be replaced with aftermarket explosion-proof aluminum bellhousing. Original OEM bellhousing must have approved scattershield constructed of minimum .125 inch by three inch steel, 270 degrees around flexplate. Only external lines allowed are for transmission cooler. Splined drive flange coupler or torque converter (10 inch minimum) only.
Manual: Must be unaltered, three or four speed, OEM production case and have a working 7.25 inch minimum diameter, steel and/or aluminum, single or multi-disc clutch and pressure plate bolted directly to flywheel/flexplate. These components must rotate, consistent with engine rpm, while car is in any gear. Must use explosion-proof steel bellhousing with one hole for throw out bearing lever or hose, must be 270 degrees around top of clutch and flywheel/flexplate area. Hydraulic clutch pedal allowed with manual transmission only.
Drive Shaft: Minimum two inch diameter, white, steel drive shaft. Steel slip-yokes only. 360-degree drive shaft loop required and must be constructed of at least .25 inch by two inch steel, or one inch tubing, mounted six inches back from front U-joint.
23. ENGINE COMPARTMENT: Rear of engine (bellhousing flange) must be mounted at least 72 inches forward from centerline of rear axle. Engine offset must be kept within two inches of centerline of front crossmember with engine level. Minimum 11 inch engine height from ground to center of crankshaft. V-belt aluminum or steel pulleys only. Copper/brass or aluminum radiator only and must be mounted in front of engine.
24. ENGINE OPTIONS AND SPECIFICATIONS:
(A) Unaltered sealed GM crate engine #88958602. Upon inspection, any different, altered, or missing GM seal bolts will result in disqualification, loss of all IMCA points for the season, $1,000 fine and a one year suspension. Driver using crate engine cannot claim engine or have engine claimed.
(B) Claim engine, with following specs: All engines must be able to be used in conventional passenger car without alterations. External engine casting and threaded holes cannot be altered. Must use OEM steel GM, Ford or Chrysler block and heads. No Ford SVO or Chrysler W components allowed. Only GM block numbers allowed are: 3892657, 3914678, 3932388, 3932386, 3956618, 3970000, 3970006, 3970010, 3970014, 10066033, 10066036, 14010207, 14010209, 14010287, 14016376, 14016379, 10054727, 14088528, 14088548, 14088552, 14093638, 14101148. Stroke must match block. Maximum .60 inch overbore. Maximum 361 c.i (GM); 363 c.i. (Ford); 370 c.i. (Chrysler), to be checked with pump, or by visual inspection of part and/or casting numbers, pistons, etc. Maximum 9 to 1 compression ratio, no tolerance, checked with a Whistler. Flat top or dished pistons only, no gas-ported pistons. OEM type steel crankshaft and rods only. Conventional flat tappet cam and lifters only, cannot alter lifter bores. OEM firing order cannot be changed. May use oil restrictors. ‘Wet’ sump oiling system only.
Only GM approved head numbers are - 14079267, 3986336, 3986339, 3986339X, 3986388, 3932441, 376445, 3928454, 3932454, 3876487, 3973487, 3973487X, 3973493, 3951598, 468642, 330862, 333882, 3998920, 3998991, 3998993, 3998997, 3970126. Maximum size valves on these heads are 2.02 inch intake and 1.60 inch exhaust. Only alterations allowed to heads are pinned or non-shouldered screw-in rocker arm studs and steel roller tip rocker arms and polylocks.
Intake must be: unaltered, approved OEM cast iron low rise, two- or four-barrel; or unaltered Weiand aluminum - ‘IMCA stamped’ Chevrolet #7547-1; Ford 302, #7515; 351 Windsor # 8023; 351 Cleveland #7516. Disqualification, loss of points and purse, and $250 fine if any alterations are found to heads and/or intake.
OEM type unaltered harmonic balancer only. OEM type steel or aluminum water pumps only.
25. ENGINE CLAIMING RULES: Refer to 2007 Official Rule Book for claim eligibility requirements.
(A) $425 cash claim on engine, $25 goes to wrecker for pulling engine.
(B) Claim does not include - 1. flywheel, 2. clutch, 3. pressure plate, 4. bellhousing, 5. breathers, 6. carburetor, 7. starter, 8. motor mounts, 9. oil/temp. sending units, 10. fan and pulleys, 11. clutch ball, 12. clutch arm, 13. throw out bearing, 14. dip stick, 15. water pump, 16. fuel pump, rod and plate, 17. distributor, 18. plug wires, 19. water outlet and restrictor, 20. headers.
NOTE: During engine claim, inspect heads and intake, and one spark plug must be removed to check flat top or dish pistons prior to transfer of engine to claiming driver. If, at this time, engine is found illegal, claimed driver is disqualified and suspended from all IMCA sanctioned events until such time as a $250 fine is paid, for first offense. Claimer then has option to accept or decline engine. If declined, claim is not charged against him/her. Second offense penalties will be $500 fine and/or suspension.
26. POINT STRUCTURE /PROCEDURES: Refer to Official 2007 IMCA Rule Book or www.IMCA.com.
27. EIRI: (Except in rare instances) Decisions of officials are final and binding without exception. In some cases, track safety rules may take precedence over IMCA rules - any discrepancy between IMCA and track rules should be brought to the attention of IMCA. Any rule changes or clarifications during the course of the year will be published in Inside IMCA, the official newsletter of IMCA, and will be considered as an official part of these rules.