Revised December 2008. Revisions/clarifications underlined, recommendations italicized, amendments underlined and italicized (date amended).
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 PUBLICATIONS OF OR COMPLIANCE WITH THESE RULES AND/OR REGULATIONS. They are intended as a guide for the conduct of the sport and are 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 RESULT FROM SUCH ALTERATION OF SPECIFICATIONS. Any interpretation or deviation of these rules is left to the discretion of the officials. Their decision is final.
2009 Crate Model
1. SAFETY EQUIPMENT: Rules apply at all times car is on track. Snell-rated SA2000, SA2005 or SFI 31.1/2005 helmet required. Roll bar padding required in driver compartment (Fire retardant recommended). SFI-approved full fire suit required. Fire retardant gloves, shoes and neck brace (or head and neck restraint) required. Recommended: Fire retardant head sock and underwear; collapsible steering shaft. Driver-side window net required, minimum 16 inch by 20 inch ribbon or mesh style, and must be mounted so latch is at top front of window. Minimum three inch wide SFI-approved 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: Must be constructed of 2 inch by 2 inch square steel tubing or minimum 1.75 inch round tubing – with minimum wall thickness of .083 inches. Minimum wheelbase of 103 inches, maximum 105 inches, both sides.
3. ROLL CAGE: Main roll cage must be at least 1.5 inch O.D. tubing with minimum wall thickness of .083 inches. Driver’s head must not protrude outside cage with helmet on.
4. DOOR BARS: Minimum three driver door bars must be at least 1.5 inch O.D. tubing, minimum wall thickness of .083 inches.
5. BODY (see body diagram for specific dimensions): No composite body panels allowed except roof rock guard and hood scoop. No fins or lips anywhere along length of car. Maximum body width at bottom of doors is 82 inches. Minimum ground clearance is 3 inches. Must have IMCA approved stock-appearing nose piece (molded type material) mounted in approved manner. Headlight decal package required. No part of body can be wider than 90 inches. Roof must be stock appearing, rounded down in all directions and mounted level and parallel to body and centered on car. Maximum 1.5 inches rolled down rock guard allowed on roof. Roof supports and window side panels must extend to edge of body. Window side panels must resemble all aspects of drawing – must have opera window and be same on both sides. Rear spoiler may be maximum 8 inches in material height and maximum 72 inches wide. Spoiler may have stiffener, must be 1 inch or more down from top. Maximum of three spoiler braces allowed, must be mounted in line and must resemble all aspects of drawing. No covers or inner panels allowed. No rear filler panel required.
6. DRIVER COMPARTMENT: Minimum three windshield bars in front of driver. Lexan or aluminum cowl panel in front of driver allowed, but can be no wider than cockpit and no farther back than steering wheel. Driver must be sealed off from track, driveline, engine, fuel cell, suspension components, battery, coolers, pumps, fuel and oil lines. Aluminum high-back seats only, must be bolted in. No mirrors. No driver-adjustable devices allowed while car is in competition except brake adjuster and right front brake shut-off.
7. FRONT SUSPENSION: Must be of A-frame or strut configuration.
8. STEERING: Rack and pinion steering allowed. Quick-release steering wheel required.
9. SHOCKS: Must be constructed of aluminum or steel. One shock per wheel plus one additional shock allowed in lift- or pull-bar area. No Schrader or bladder type valve allowed. No remote-reservoir shocks. One or all shocks can be claimed for $200 each, counting as one claim on card, following claim procedures (Refer to General Rules and Procedures).
10. SPRINGS: Coil springs must be steel. Leaf springs may be composite or steel.
11. REAR SUSPENSION: No independent rear suspension. One spring per wheel. No springs or rubber bushings allowed on control arms. Limiting shock, chain or tether allowed on left rear only.
12. REAR END: Approved quick changes allowed. No 9” Ford, open tube or cambered rear ends. Rear end coolers allowed.
13. BUMPERS: Must be either capped, or bent forward at ends, no sharp edges. All cars must be equipped with tow hook or similar device front and rear.
14. TIRES/WHEELS: WRS-2 D55 Hoosier Race Tires only. 29 by 11 by 15 allowed anywhere on car. 28.5 or 28 by 11 by 15 ‘stagger tires’ allowed on left rear only. No softening, conditioning or grooving (Refer to General Rules and Procedures for automatic penalties). Grinding allowed on tire tread only. Maximum 14 inch wide wheels; bead locks allowed on right side only. External bead lock only, cannot make wheel wider than 14.75 inches. Foam, plastic, or aluminum (must be bolted behind bead lock rim) mud plugs allowed on any wheel.
15. BRAKES: Must be operative and lock up all four wheels during any inspection. Steel brake rotors only. No ceramic coatings allowed. Brake shut-off allowed on right front only (electric or mechanical).
16. EXHAUST: Round tube headers only. All primary header tubes must enter directly into one collector, at same point, at end of header. Must remain dual exhaust, no crossover, merge collectors or Tri-Y headers.
17. FUEL SYSTEM: Holley 4 barrel carburetor, all components (float bowls and main body) must be Holley manufactured. Metering blocks and base plate may be billet aluminum non-Holley. No aerosol-style carburetors allowed. Carb subject to $500 cash claim or exchange following claim procedures (see general rules). Maximum one-inch thick, one piece open plastic intake to carburetor spacer for GM crate engine #88958604. Maximum two-inch open plastic spacer allowed for GM crate engine #88958602. Maximum .100 inch thick carburetor gaskets only. No air dams or devices allowed to increase air flow to carburetor outside of air cleaner. Maximum two-inch tall spacer between carburetor and air cleaner base. No cold air boxes, air cleaner duct work, or fuel cooling devices. No top flow air cleaner housings. Mechanical OEM type push rod fuel pumps only. Racing fuel cell required, maximum 32 gallon capacity, must be in minimum 20 gauge steel container. Must mount with minimum two solid steel straps around entire cell, two inches wide and .125 inch thick. Cell must be mounted between frame rails behind rearend, bottom of cell can be no lower than center section. Fuel cell vents, including cap vent, must have check valves, and bladders are highly recommended. If fuel cell does not have aircraft style positive seal filler neck/cap system - a flapper, spring or ball type rollover valve is required. Fuel cell guard must come to bottom of fuel cell and be minimum 1.5 inch O.D. tubing.
18. FUEL: Gasoline only. No E85 allowed. Racing fuel allowed. No performance enhancing additives or pressurized fuel systems. Fuel must pass both dielectric meter and chemical tests for additives. Fuel sample may be taken from any car at any time (Refer to General Rules and Procedures for automatic penalties).
19. WEIGHT: Cars using GM crate engine #88958602 must weigh minimum 2,250 pounds after race with driver. Cars using GM crate engine #88958604 must weigh minimum 2,450 pounds after race with driver. No tolerance. Weights must be painted white with car number on them. Must be securely fastened with minimum two .5 inch steel bolts, inside body panels, not on rear bumper. No weights and/or loose objects in driver’s compartment. The only composite materials allowed are roof rock guard and hood scoop.
20. BATTERY/STARTER: Battery must be securely mounted to chassis, protected by tubing and positive terminal must be covered. Starter must be in working order. Car must start under its own power. Car must leave initial staging area on demand, unaided, or go to rear of that race.
21. GAUGES/ELECTRONICS: No unapproved cameras, transmitting or listening devices, timing retard controls, or digital gauges (including tach). No electronic monitoring computer devices capable of storing or transmitting information except analog tach. 6,200 RPM maximum limiting chip is required for all competing cars. Altering or bypassing the RPM limiting function will result in the penalties described in rule #24. HEI or MSD ignition only. HEI must use P/N 8728, MSD Soft Touch Rev Control with chip. P/N 6420 MSD 6AL, P/N 6430, MSD 6 ALN Ignition Control Box with Rev Limiter Built-In permitted. P/N 8738 MSD Soft Touch Rev Control may be used with MSD 6T, 6TN ignitions. No adjustable ignition control boxes, box can be connected to engine only. Only one ignition box allowed. No additional ignition accessories allowed. Only change allowed to ignition box is one high-end rev-limiter setting. This setting can be changed through one chip only. No crank triggers or magnetos. No electronic traction control devices. (Refer to General Rules and Procedures for automatic penalties)
22. TRANSMISSION/DRIVESHAFT: Must have at least two gears forward and one gear reverse, plus a neutral position. Must be able to put in and out of gear with car sitting still and engine running. No overdrive transmissions. All manual transmissions must bolt directly to back of bellhousing which bolts directly to engine block. Automatic transmissions must bolt directly to engine block. A flexplate shield must be used with automatics. Must use steel or aluminum driveshaft in similar design to standard production, must be painted white. 360-degree drive shaft hoop required, minimum .25 inch by two inch steel strap, or one inch tubing, mounted six inches back from front U-joint.
23. ENGINE LOCATION: Measured from centerline of upper ball joints to center of number one spark plug hole. Maximum setback is 8 inches.
24. CRATE ENGINE RULES: Unaltered sealed GM crate engines only. GM seal bolt exception is IMCA approved and issued cable-lock rebuild system. Details to be announced. GM part number 88958602 (steel headed) or 88958604 (aluminum headed) allowed. All crate engines must remain as they came produced from GM. Absolutely no internal or external alterations of any kind can be done to the engine. Upon inspection, any altered parts and/or different/altered/missing GM seal bolts will result in disqualification, loss of all IMCA points for the season, $1,000 fine and a one year suspension.
25. ENGINE PROTEST PROCEDURES: Within 5 minutes after race, any driver starting feature may, for $400, protest any engine. $100 of the protest fee goes to the track and will not be refunded, regardless of protest outcome. $100 of the protest fee is for GM seal bolts. Driver may only make one protest per event, may not protest another driver finishing in a position behind them and may not protest same driver more than once per calendar year. One protest allowed per event, draw will determine if multiple protests made. Under this protest, following MUST be inspected: intake manifold, cylinder head (removal required), bore and stroke, and visual inspection in oil pan. If engine being protested is found legal, $200 protest fee will be paid to driver being protested and the engine resealed. $300 will be returned to protestor if engine is found illegal. If parts are found illegal, or if driver refuses to submit to protest, it will result in disqualification, loss of all IMCA points for the season, $1,000 fine and a one year suspension. Promoter may protest any engine.
26. POINT STRUCTURE/PROCEDURES: Refer to General Rules and Procedures.
27. EIRI: (Except in rare instances) Decisions of IMCA Official(s) 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.
For more information, call Tom Gutowski at 402-350-6120 or Josh McGowan - 319-310-3095.
Copyright © 2009 IMCA. All rights reserved.
No part of this publication may be reproduced, stored, or transmitted in any form, without prior written permission.
