2019 IHRA Rulebook

IHRA 35 approved fasteners and must be identifiable as to grade. FIRE EXTINGUISHERS: All cars in NFC and TS must be equipped with a manually controlled onboard fire extinguisher system containing a minimum of five pounds of agent or specified amount of agent. Unless specified otherwise under Class Requirements. It must be mounted as per manufacturer’s specifications with the primary nozzle(s) directed to protect the driver. In the case of more than one bottle, each bottle must have its own distribution tubing and nozzles. The use of nozzles or tubing other than that recommended by the manufacturer is not permitted. All distribution tubing must be steel, aluminum tubing is prohibited. Two discharge nozzles are placed at the front of the engine - one on each side - and one nozzle is located in the driver’s compartment near drivers feet. It is recommended that there are no more than three nozzles per bottle. Upon activation of the system, the contents of the bottle(s) must be totally discharged. All containers must be mounted in IHRA approved locations. Remote cables must be installed within easy reach of the driver. All bottles must be DOT rated if mounted in the drivers compartment. Follow the manufacturer’s recommendation regarding installation, especially on bend radius and protection from crimping or kinking. All fire systems must use steel lines and distribution nozzles and must be equipped with a pressure gauge. All bottles must be identified with a gross loaded weight figure or recognized measurement system if AFFF is the agent utilized in the system. It is the responsibility of the competitor to weigh the bottle prior to each event. It is recommended that each contestant and/or his crew have a loaded serviceable extinguisher in his possession carried in the push car or otherwise available for immediate use. Dry chemical or C02 type extinguishers (2-1/2 lbs. minimum size) are recommended. FIREWALL: Each car in competition must be equipped with a flame proof and fuel proof firewall including fiberglass or carbon fiber extending from side to side of the body and from the top of the engine compartment upper seal (hood, cowl, or deck) to the bottom of the floor and/or belly pan. Firewall must be constructed to provide a bulkhead between the engine and driver’s compartment. All holes or openings must be sealed with minimum .024 steel or .032 aluminum, or as specified by classification. All openings around pedals, shifters, brake handles, etc., must be covered either internally or externally to aid in sealing the drivers compartment from outside sources. FLASH SHIELD: Injector tubes may extend through individual holes in the hood, but carburetors may not be openly exposed or uncovered. In lieu of hood, carburetors must be equipped with a metal flash shield which covers the top, back, and sides, to prevent gas from being siphoned into the air stream or blown into the driver’s face. FLOORS: All cars not having floors must be equipped with floor pans made of .024 steel or .032 aluminium, which must extend the full length and width of the driver’s compartment, to the rear of the driver’s seat. Cars equipped with belly pans made of fiberglass, or other breakable material, must have metal subfloors. Belly pans enclosing engine compartment must contain suitable drain holes ahead of firewall. FLYWHEEL SHIELD & MOTOR PLATE: GENERAL: Absolutely no modifications to a manufactured design are permitted on SFI Spec 6.1, 6.2 and/or 6.3 flywheel shields and/or liners. Titanium bellhousings must be re-inspected and re-certified yearly. SFI 6.2 steel bellhousings must be re-inspected and re-certified every two years, SFI 6.1 steel housings must be re-inspected and re-certified every five years or as specified by the manufacturer. The flywheel shield must be fastened to the engine and motorplate with a full complement (all available engine bolt holes or as specified by the manufacturer) of grade 8 bolts or high strength studs. The use of allen bolts to fasten the shield to engine or motorplate, to fasten covers, etc, is prohibited.All bolts (not studs or nuts) used for flywheel shield mounting, covers, etc, must be identifiable as to grade; all nuts and bolts associated with flywheel shield mounting, covers, etc, must be full standard depth, width, etc, (reduced thickness bolt heads, hollow bolts, half nuts, thin wall nuts, etc, prohibited). Maximum depth of flywheel shield is 8 5/8”. Maximum thickness of all motor plates, midplates, mounting plates installed between engine and flywheel shield is 1/2”. All covers and fasteners associated with the flywheel shield must be installed prior to starting engine at any time, including warm-ups. Maximum spacing between flange fasteners in the flywheel shield is 7”. Chemical milling or any other structure weakening procedures are prohibited. Welding to repair a flywheel shield not conforming to the requirements is prohibited unless it is performed by the manufacturer and recertified by the manufacturer prior to use. Cooling holes in the motor plate are limited to a maximum of two 2-inch diameter holes (preferred to be outside of the oil pan area). SFI 6.2 flywheel shields may have one 2-inch maximum diameter hole in the bottom of the back face of the shield. The opening in the motor plate for the crankshaft flange may not exceed the crankshaft flange diameter by more than one inch. FLYWHEEL SHIELD: TF, PFD, NFC: Cars equipped with a clutch must have a flywheel shield (bellhousing) that meets SFI Spec 6.2 and is labeled accordingly. A one-piece motor plate constructed of 1/4 inch minimum thickness 4130 chrome moly steel and fitting between the engine and flywheel shield according to the requirements of SFI Spec 2.2,