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2013 Hobby Stock Rules
The Hobby Stock rules are separated into three levels of compliance so drivers and car builders have more guidance when working on their cars.
These are minimum requirements that every car and driver must adhere to. These requirements are generally inclusive of driver, competitor, staff or spectator safely. CAR techs shall be inspecting and enforcing adherence to these rules.
These are recommendations that CAR suggests for additional safety or for a more competitive and exciting racing. Cars are not excluded from racing if these recommendations are not met. The intent behind these recommendations is to provide guidance for drivers/owners during construction and maintenance of their cars without requiring significant investment to race.
These set of items are completely optional for the driver as they don’t have a significant impact on safety or performance, but often come up in discuss therefore they are have been listed below for completeness.
Decisions of officials are the final and binding without exception. In all cases, track safety rules will take precedence over oval rules – any discrepancy between track rules should be brought to the attention of track official. Any rule changes to clarifications during the course of the year will be posted on the web site and will be considered as an official part of the rules.
1. Car Frame
1.1.1. Any American OEM full body rear wheel drive passenger car, 1964 or newer, full frame or uni-body.
1.1.2. Minimum 107.5 inch wheelbase, maximum one inch difference from side to side.
1.1.3. Frame must match body — GM to GM, Ford to Ford, Chrysler to Chrysler — and wheelbase to wheelbase.
1.1.4. All uni-body cars must have sub frame connectors.
1.1.5. No Camaros, Firebirds or Mustangs.
1.1.6. Steel body cars only.
1.1.7. Rear of frame behind rear tires, no further forward than one inch behind factory seam, may be replaced in OEM location with 2" x 3" steel tubing with 0.095" wall thickness. Factory seam must remain visible.
1.1.8. No part of frame or body can be lower than 4" from ground except front cross member, oil pan, sway bar and exhaust, with driver in car.
1.1.9. Body mounts are not to be removed to lower the body on the frame. Body mounts must be stock height, but may be replaced with polyurethane or steel.
1.2.1. Frame may be “X” braced.
2. Front Suspension
2.1.1. All components and mounts must be steel, unaltered OEM, in OEM location and match frame. (* refer to springs section for exceptions).
2.1.2. Rubber, nylon or steel lower A-frame bushings only - no offset or bearing type.
2.1.3. No Weight jacks allowed.
2.1.4. No altering of suspension parts. All components must mount in stock location using stock adjustments. (* refer to springs section for exceptions).
2.1.5. ~NEW~ Maximum of 2 ½” camber on right front wheel.
2.3.1. Stock sway bars permitted if mounted with stock components. No rear sway bars on cars under 113” wheelbase. No manufacturing of rear sway bar mounts.
2.3.2. Polyurethane or steel suspension bushings that replace stock rubber bushings are allowed.
3. Rear Suspension
3.1.1. All components and mounts must be steel, unaltered OEM, in OEM location, and match frame. (* refer to springs section for exceptions).
3.1.2. No independent rear suspension.
3.1.3. Rubber or nylon control arm bushings only, no offset or bearing type.
3.1.4. Upper control arm mounts on rear end must be level with each other.
3.1.5. No fabricated third links or torque arms.
3.1.6. No sway bars, pan hard bars, spring spacers or rubbers, chains or cables.
4.1.1. One unaltered steel, nonadjustable, non-take apart, OEM-mount shock, in OEM location, per wheel.
4.1.2. No coil over, air, or remote reservoir shocks.
4.1.3. No coil over eliminators.
4.1.4. No Schrader or bladder type valve allowed.
4.1.5. No AFCO or other street/stock/racing shocks.
5.1.1. One steel spring per wheel only in OEM Location.
5.1.2. All coil springs must be minimum 4.5 inches O.D. and non-progressive.
5.1.3. No spring spacers, no lumber and no chains allowed.
5.1.4. No racing coil springs allowed, unless sway bar has been removed.However coils must be securely fastened.
6. Car Body
6.1.1. All bodies must be unaltered OEM in OEM location and match frame.
6.1.2. Front body mounts must be visible.
6.1.3. Full floor boards must be steel.
6.1.4. Sunroofs and T-tops must be reinforced and enclosed in sheet metal.
6.1.5. No spoilers, hood scoops, ground effects or skirting.
6.1.6. Hood must be separate from fenders and in OEM location.
6.1.7. Hood and Trunk lid cannot be gutted, must remain steel.
6.1.8. No overlapping or shortening of body panels.
6.1.9. Side and rear windows must be open and clear.
6.1.10. Trunk floor must be removed over rear end housing.
6.1.11. No reflective body panels.
6.1.12. All vehicles will start each race day with all body panels in place and as dent free as is reasonable.
6.1.13. All glass must be removed, all trim, side mirrors, interior mirrors, headlights, marker lights, rear lights and light lenses, etc. must be removed.
6.1.14. No opening doors all doors must be bolted or welded shut.
6.1.15. If trunk and hood hinges are removed, they must be secured with 4 pins, one in each corner.
6.1.16. Numbers must be painted or decaled on the roof and front side doors. Minimum 16” in height and 2 ½” in brush width. Numbers must be in contrasting colour with the vehicle. All numbers must all be similar in appearance. The base of the roof number must face the passenger side. Any number deemed illegible may have to be changed.
6.1.17. All flammable materials must be removed.
6.1.18. Hood and trunk must be securely fastened and back of hood must be sealed off from driver compartment with metal.
6.2.1. Inner fender wells on the front fenders may be removed to allow inspection of the front suspension.
6.2.2. Wheel wells may be slightly trimmed for tire clearance.
6.2.3. Numbers painted on rear driver’s side of trunk lid.
6.3.1. Aftermarket plastic nose pieces allowed recommended matching body. Must have stock bumper under nose.
6.3.2. Rear edge of trunk may be trimmed for aftermarket tail piece.
6.3.3. Trunk floor may be completely removed.
6.3.4. Maximum seven inch metal sun visor may be added to top of windshield opening.
7. Bumpers / Rub Rails
7.1.1. Rub rails are allowed. Ends must be angled in so nothing can catch on them. No bigger than 1” x 2” or 2” round tubing.
7.1.2. Must be attached to body wheel well to wheel well.
7.1.3. All vehicles must have tow hoops, hooks, or chains mounted to the frame front and rear.
7.1.4. No sharp edges allowed on bumpers, rub rails or bolts.
7.1.5. Bumpers must be in stock location. Front and rear bumpers are mandatory.
7.1.6. No bars past outside edge of body other than rub rails.
7.1.7. ~NEW~ Front and rear bumpers must be capped to the body with 3/16” x 4” steel plate.
7.3.1. Aftermarket: Fabricated tubular bumpers allowed, but must be covered by plastic nose or tail piece and bent to fit with rounded ends. Main bumper bar must be minimum 1.5 inch O.D. (maximum two inch) with 0.083 inch (maximum 0.125 inch) wall thickness on front, and 1.75 inch O.D. with 0.120 inch wall thickness on rear.
8.1.1. No titanium, magnesium or carbon fibre products.
8.1.2. No gun-drilled, tubular, hollow bolts or studs.
8.1.3. Steel fasteners only.
8.1.4. No lead or ballast.
8.1.5. Any item deemed as ballast will be required to be replaced i.e. Fuel cell, straps, fuel cell cans, battery boxes, etc.
9. Roll Cage
9.1.1. Main cage must consist of continuous hoops, minimum 1.75 inch O.D. tubing, with a minimum wall thickness of 0.095 inch, low carbon or mild steel recommended.
9.1.2. Four-post roll cage required, front down bars and rear hoop must be welded to OEM frame.
9.1.3. Driver’s head must not protrude outside cage with helmet on.
9.1.4. Rear hoop must have “X” brace, consisting of one full horizontal and one full diagonal bar, minimum 1.25 inch O.D. with 0.083 inch wall thickness.
9.1.5. Front down bars must be tied together.
9.1.6. Passenger side front down bars must be maximum 11 inches in from top of door.
9.1.7. Must be minimum 40 inches between front and rear down bars at top of door panel. Maximum 41 inches (48 inches for 1988-1996 GM bodies) from top center of windshield to front edge of rear hoop; maximum 13 inches (20 inches for 1988-1996 GM bodies) to front edge of top halo.
9.1.8. Minimum one cross bar in top halo.
9.1.9. May have maximum two horizontal bars, (in addition to bar tying front frame horns together) for radiator protection; must be behind bumper, within confines of body, no wider than stock frame horns.
9.1.10. Rear kickers (down bars) and engine hoop must be minimum 1.25 inch OD tubing, with 0.083 inch wall thickness.
9.1.11. Fuel cell protection is required, must be mounted frame rail to frame rail, no higher than fuel cell, inside trunk area with maximum 1.75 inch OD tubing.
9.1.12. All bars must be inside body.
9.1.13. All door bars and uprights must be minimum 1.75 inch O.D. with 0.095 inch wall thickness.
9.1.14. Minimum three door bars, both sides, parallel to ground, and perpendicular to driver.
9.1.15. Minimum three uprights on passenger side.
9.1.16. Steel door plates, 18 gauge or 0.049 inch minimum thickness, must be securely welded to outside of door bars on driver’s side. Plate must cover area from top door bar to frame and from rear down post to five inches in front of seat.
9.1.17. Must be visible for inspection.
9.1.18. Roll bar padding required in driver compartment (Fire retardant recommended).
9.1.19. All joints must be welded. No threaded or brazed connections will be allowed.
9.2.1. All stress points of the main cage must be gusseted.
10. Drivers Compartment
10.1.1. Minimum of 3 windshield bars 6" apart in front of driver.
10.1.2. Aluminum high-back seat only and must be bolted to roll cage.
10.1.3. Seat must be no further back then rear edge of B-pillar and top edge of seat must be inside all confines of roll cage.
10.1.4. A steel firewall must separate the driver from the fuel cell.
10.1.5. Dash not to extend more than 24 inches back from top of firewall.
10.1.6. Dash must be flat, rear can be no higher than front, except for cowl in front of driver.
10.1.7. All Interior upholstery, carpet and trim must be removed.
10.1.8. All holes in interior compartment must be sealed. All vehicles will have fully sealed front and rear firewalls. All holes in the interior compartment will be sheet metaled over and welded or pop-riveted in place.
10.1.9. No driver-adjustable devices allowed while car is in competition.
10.1.10. Mirrors are not allowed or reflective sun visors.
10.1.11. Minimum 16 inch by 20 inch ribbon or mesh style, and must be mounted so latch is at top front of window.
10.1.12. No part of net or mounting system to be outside the car.
10.1.13. Driver must be seal off from track, driveline, engine and fuel cell.
10.2.1. Rear firewall and speaker deck must be metal and be of OEM design for that body.
10.2.2. Minimum 22 gauge Steel to be used for rear firewall.
10.2.3. OEM dash be removed.
10.2.4. Minimum 22 gauge Steel to be used for repairing holes.
10.3.1. Inside rear quarter panels, below window level, may be removed.
10.3.2. Doors may be gutted.
10.3.3. Floor pan can be modified for exhaust clearance only, must remain completely enclosed.
10.3.4. ~NEW~ 5lb ABC type fire extinguisher within driver's reach with steel mounts that are bolted not riveted.
11.1.1. No unapproved cameras, transmitting or listening devices.
11.1.2. No timing retard controls, or digital gauges (including tachometer).
11.1.3. No electronic monitoring computer devices capable of storing or transmitting information except analog tachometer.
11.1.4. No electronic traction control devices.
11.1.5. No ignition control boxes, OEM ignition only.
11.1.6. All ignition rotors, caps, coils and modules must remain OEM appearing.
11.2.1. Alternators allowed.
12.1.1. All components must be steel, unaltered OEM, in OEM location and match frame.
12.1.2. No quick steering boxes or remote power steering reservoirs, Steering must have a minimum of 2 turns lock to lock.
12.2.1. Collapsible steering shaft.
12.3.1. OEM steering column may be replaced with steel knuckles and steel steering shafts.
13. Engine Compartment
13.1.1. Engine must be in OEM location.
13.1.2. GM metric frame, center of fuel pump must be located in front of cross member.
13.1.3. Frame and cross member may not be altered for engine placement.
13.1.4. Steel engine mounts only, no mid-plates.
13.1.5. Engine must be OEM appearing, must be able to be used in conventional passenger car without alteration. GM with GM, Ford with Ford, Chrysler with Chrysler.
13.1.6. Steel or aluminum V-belt pulleys only.
13.1.7. Overflow tubes must be directed to ground, between frame rails.
13.1.8. Accumulators and Accusumps must be mounted under hood.
13.3.1. Electric fans allowed.
14.1.1. Radiator must be mounted in front of engine in stock location.
14.1.2. Minimum 2 core cooper/brass or aluminum radiator.
14.2.1. Radiators can have a minimum 1 litre catch can.
14.3.1. Cooling systems may be modified. Can include an aftermarket aluminum radiator but must fit stock mounts without major modifications.
15.1.1. Maximum 361 cubic inches (GM); 363 cubic inches (Ford); 370 cubic inches (Chrysler).
15.1.2. OEM passenger vehicle production block only.
15.1.3. Must use stock rods and crankshaft.
15.1.4. No GM Bowtie, Ford SVO or Chrysler W blocks.
15.1.5. Castings and fittings cannot be changed, no machine work on outside of engine. Or on front or rear of camshaft.
15.1.6. No “double bump” heads. No Vortec heads. No angle plug heads. No machining, grinding, porting, or polishing. No port matching. Stock casting lines and flash must remain and be visible.
15.1.7. Any grinding marks on the intake or exhaust ports will result in an automatic disqualification. No machining bowl area. You cannot install larger valves in small valve heads. No enshrouding of intake valve by machining into the side of the combustion chamber. No angle milling of heads.
15.1.8. Minimum combustion chamber, Small Block 350-74cc, 305-56cc
15.1.9. Stock stamped steel rockers, no roller rockers and no roller lifters. No 1.6 rocker arms on small block Chevrolet.
15.1.10. No stud girdles.
15.1.11. Hydraulic lifters, flat tappet cam/lifters only.
15.1.12. No mushroom lifters.
15.1.13. No enlarging of push rod holes. Technical officials will have the final say on whether any cylinder heads have been illegally machined. Valve train components must be stock as produced.
15.1.14. No bow tie or high rise intakes.
15.1.15. OEM firing order cannot be changed.
15.1.16. ‘Wet’ sump oiling system only.
15.1.17. Stock replacement pistons only. Flat top or dished pistons only. No domes. Pistons must have 4 valve reliefs where applicable.
15.1.18. Maximum compression ratio is 9.0 to 1, no tolerance. Compression ratio checked using Whistler and cubic inches checked using pump, OR by visual inspection, such as part numbers, casting numbers and flat top or dish pistons (track option which method is used).
15.1.19. Maximum lift .450” intake and .450” exhaust. No hydraulic roller cams. No overhead cams. Camshafts must have maximum 250 duration.
15.1.20. Cylinder heads must be in stock condition. Small block Chevrolet 305 cubic inch cylinder heads may be used on a 350 cubic inch engine but must retain stock valve size or maximum 1.84 intake and 1.5 exhaust. All other small block Chevrolet heads will have a maximum valve size of 1.94 intake and 1.5 exhaust.
15.1.21. Small block Chevrolet press in rocker studs only.
15.1.22. No Gasket matching.
15.3.1. Aluminum water pumps on Chevy’s.
15.3.2. Accumulator allowed – cannot be located between seat and door bars.
16.1.1. No aftermarket intake manifolds, must be cast iron.
16.1.2. Must have air cleaner with an air filter element to act as a flame arrestor.
16.3.1. Intake manifold may use 4 to 2 barrel adapter or use 2 barrel intake manifold.
17.1.1. ~NEW~ All cars must have either a:
17.1.2. Air cleaner top/stud cannot direct air into carburetor.
17.1.3. No ram air induction.
17.2.1. Carburetor adapter/spacer allowed, maximum 1.20" thick, including gaskets.
17.2.2. Choke plate may be removed.
18.1.1. No performance ignition parts. Stock coils only.
18.1.2. No additional ignition accessories.
18.1.3. ~NEW~ Aftermarket OEM ignition wires allowed.
19.1.1. Cast iron exhaust manifolds. No center dump exhaust manifolds.
19.1.2. Must remain dual exhaust, no crossover or “Y” pipes.
19.1.3. No exhaust through body panels or fenders.
19.1.4. Maximum 95 DBA at 100 feet.
19.1.5. No exhaust sensors.
19.1.6. Exhaust pipes maximum O.D. is 2 ½”.
19.1.7. Exhaust must extend past firewall and turn towards ground or come out in front of rear wheels.
20.1.1. Each vehicle will be equipped with a master on/off switch. This switch must be within the driver’s reach when belted in and within the reach of persons standing outside the driver’s door (i.e. Left hand corner of dash). This switch must be clearly marked "OFF" and "ON".
20.1.2. One 12 volt automotive battery must be securely mounted. (No industrial batteries allowed)
20.1.3. Battery must be in Marine type case
20.1.4. Securely mounted to frame or roll cage in metal frame behind seat or in trunk area between frame rails
20.1.5. Starter must bolt in OEM location.
20.1.6. Car must have capability of starting without being pushed or pulled.
20.1.7. Car must leave initial staging area on demand, unaided, or go to rear of that race.
20.1.8. ~NEW~ Each vehicle must have a second master on/off switch on the ground circuit. This switch must be in the rear of the car and within the reach of persons standing outside the driver’s door (i.e. Left hand corner of rear window or rear side window). This switch must be clearly marked "OFF" and "ON".
21.1.1. Forward and reverse gears must be operational plus neutral position.
21.1.2. With motor running and car in still position, must be able to engage car in gear and move forward, then backward.
21.1.3. Only OEM production type transmissions allowed - manual or automatic.
21.1.4. No five speed (or more) transmissions, “in and out” boxes, or quick change devices allowed.
21.1.5. Unaltered flex plate must be full OEM, or OEM replacement.
21.1.6. No aluminum flywheels or clutch components
21.1.7. All pressure plates and clutch discs must be stock sizes (no aftermarket miniaturized assemblies. No multiple disc systems.
21.1.8. No ram clutches.
21.1.9. Automatic transmissions must remain in OEM or OEM replacement case, with a functioning OEM appearing pump.
21.1.10. ~NEW~ Manual transmissions must have an approved scatter shield around 270 degrees of clutch assembly and/or a ¼” steel plate shield that follows the contour of the transmission hump.
21.1.11. Automatic transmissions must use minimum 10" torque converter.
21.1.12. Flex plate must be full, unaltered OEM or OEM replacement.
21.1.13. All driveshaft and safety hoops will be painted white.
21.1.14. No aluminum drive shafts
21.1.15. Steel slip-yokes only
21.1.16. 360-degree drive shaft loop required and must be constructed of at least 1/4" x 2" steel, 1" tubing, or 4" diameter pipe with 1/8" wall thickness mounted within 6" from front U-joint.
21.1.17. ~NEW~ Second rear drive shaft hoop.
22. Rear Differential
22.1.1. Rear end must be stock to year and model of car being used. All rear end mounts must remain stock. (*9" Ford rear end allowed, but must be mounted like OEM rear end (centered) for that make and model.)
22.1.2. No adjustable lowering blocks.
22.1.3. Full steel spool, steel mini spool or welded spider gears only.
22.1.4. OEM or OEM Replacement Steel axles only.
22.1.5. No quick change devices.
22.1.6. No torque-dividing differentials.
22.1.7. No full floater rear ends.
22.1.8. No lightened ring gears
23.1.1. Brakes on all 4 wheels must be in working order. Periodic brake checks will occur.
23.1.2. Steel, unaltered OEM, or unaltered OEM replacement, operative four wheels, disc (front) and drum (rear) brakes and must match frame.
23.1.3. Bolt pattern may be changed.
23.1.4. No brake shut-off or pressure sensitive devices.
23.1.5. No brake bias adjusters/proportioning values.
23.1.6. Steel lines only must be visible.
23.1.7. No aftermarket brake pedal assemblies.
23.1.8. Master cylinder must be in OEM location.
23.1.9. No antilock brake systems.
24. Tires and Wheels
24.1.1. ~NEW~ Unaltered 205/70X15SW or G60/15American Racer tires and Hoosier G60/15 tires also allowed.
24.1.2. No softening compounds, conditioning, grinding, or grooving of tires.
24.1.3. No re-caps.
24.1.4. ~NEW~ Maximum 15x8 steel wheels.
24.1.5. 1” wheel nuts.
24.1.6. No bead locks.
24.1.7. No bleeder valves.
24.1.8. A car must run all 4 wheels of the same diameter, width and offset. Maximum ¼” offset tolerance.
24.1.9. No snow or all terrain tires.
24.1.10. No tire studs.
24.1.11. Tires must be inside body.
24.1.12. No wheel spacers.
24.2.1. Larger studs allowed.
24.3.1. ~NEW~ Up to 4” Wheel offsets are allowed, but must be the same on all four wheels.
24.3.2. Tire tubes allowed
25. Fuel System
25.1.1. Mechanical fuel pumps only. No aluminum fuel pump push rods.
25.1.2. Racing fuel cell, maximum 22 gallon,
25.1.3. ~NEW~ Must be securely fastened to frame no lower than top of rear differential housing. A minimum of two solid steel straps around entire cell, two inches wide and 0.125 inch thick 25.1.4. Must be in minimum 18 gauge steel container.
25.1.5. Fuel cell must be grounded to the frame.
25.1.6. No fuel cells allowed over rear end housing.
25.1.7. No adjustable fuel cell mounts.
25.1.8. If fuel cell does not have aircraft style positive seal filler neck/cap system - a flapper, spring or ball type breather rollover valve is required.
25.1.9. No fuel lines in the driver’s compartment of the vehicle. Must run through metal pipe or metal conduit.
25.1.10. No cool cans.
25.1.11. No top flow air cleaner housings, cold air boxes or air cleaner duct work.
26.1.1. Unleaded passenger-vehicle retail (“pump”) fuel ONLY. No alcohol, nitro, exotic fuels, 730 or higher specific gravity.
26.1.2. No performance enhancing or scented additives.
27. Personal Safety
27.1.1. Snell-rated SA2000, or SA2005 preferred however SA95 helmets are acceptable.
27.1.2. No "M" rated helmets.
27.1.3. All drivers must wear fire resistant coveralls or fire suits with at least a SFI 3-2A/1 rating. If single layer suits are used.
27.1.4. All drivers will wear fire resistant shoes. Any leather shoe is acceptable and the use of proper racing shoes is encouraged.
27.1.5. All drivers must wear Fire Resistant wear gloves while racing. Mechanic Type gloves are not acceptable.
27.1.6. Absolutely no material other than fire resistant fabrics are allowed.
27.1.7. Minimum 3" wide SFI-approved 5-point safety belt assembly required (Y-type shoulder harness not allowed), must be mounted securely to roll cage,
27.1.8. Certification patches will be checked and any frayed, weathered or damaged belts must be replaced.
27.2.1. Helmets should have a face shield, goggles are discouraged.
27.2.2. The use of multi-layered suits is encouraged.
27.2.3. Fire retardant neck brace
27.2.4. Fire retardant head sock and underwear
27.2.5. Shoulder harness should be mounted no more than 10” behind the driver’s head and below shoulder height Belts should be removed, cleaned and stored in a dry place out of any direct sunlight
27.3.1. Approved aftermarket racing steering wheel disconnect. (no "homemade" devices)