2008 Hobby Stock Spec Rules
1. ROLL CAGE - Must use .095 -inch tubing, at least 1.750-inch diameter for main cage and door bars. No offset cages. Four-post roll cage must be used, front and rear hoop welded to the OEM frame. Rear hoop must have "X" brace, consisting of 1 horizontal and 1 diagonal bar, 1.25 inch O.D. and .083 inch wall thickness. Front down-bars must be tied together. Must be minimum of 40 inches between front and rear down bars at top of door panel. No more than 41 inches from top center of windshield to front edge of rear hoop; no more than 13 inches to front edge of front hoop and top halo must be no less than 40 inches across, outside to outside. Required rear kickers and front hoop must be minimum 1.25-inch tubing, with .083-inch wall thickness. Three horizontal door bars on both sides are mandatory. Minimum of four uprights tied from frame to top door bar on driver side, three on passenger side. May have two bars for protection in front of radiator, behind bumper, within confines of body, no wider than stock frame horns. May tie front horns together. All bars, front and rear, must be inside body. Must have minimum of one cross bar in top of halo of roll cage. Steel door plates, 18 gauge or .049-inch minimum thickness metal, must be securely welded to outside of door bars on driver's side. Plate must cover the area from the top door bar to the rocker panel and from the rear down post to five inches in front of the seat. Must be visible for inspection. Must have tow hook front and rear. Front hoops allowed. Absolutely no square tubing or galvanized pipe allowed. Fuel cell protection bar may be used, mounted frame rail to frame rail, no higher than the fuel cell and inside the trunk area. Maximum 1.75-inch pipe.
2. SAFETY- Five point safety belts, sub belt and shoulder harness required. SFI approved full fire suit, fire retardant neck brace and fire retardant gloves required, shoes recommended. Helmets are required and must be Snell SA2000 or SA2005. Helmet must be worn at all times car is on the track and must accompany vehicle at time of inspection. Roll bar padding required in driver compartment. Fire retardant padding recommended. Belts must be mounted to cage. Belts must be within 3 years of manufacture date to be legal. No Y-type shoulder harnesses. Arm restraints or full size (minimum 16-inch x 20-inch) window net required (no string-type nets). Window net to be mounted so latch is at top front of driver side window. Kill switch required within easy reach of driver and must be clearly marked "OFF" and "ON". 360-degree driveshaft loop is required and must be constructed of at least quarter-inch by two-inch steel, or one-inch tubing, and should be mounted six inches back from front U-joint. All cars must have a high-back aluminum racing seat fastened to roll cage, NOT bolted to the floorboard. Driver’s shoulders can be no further back than the front of the window post (‘B’ pillar).
3. ELECTRONICS - No transmitting or listening devices allowed in car. No electronic monitoring computer devices capable of storing or transmitting information except tach allowed on cars. All ignition rotors, caps, coils and modules must remain stock appearing. No digital gauges allowed on car. No ignition control boxes allowed, OEM ignition only. No electronic traction control devices allowed, penalty is a one-year suspension from all A.C.S. sanctioned events and a $10,000 fine.
4. FUEL –Pump gas or racing gas will be allowed, no alcohol. Racing fuel cell required (maximum size is 22 gallon), no boat or stock automotive fuel tanks. Must be securely fastened inside trunk of car, and be mounted by at least two 1/8-inch thick solid steel straps, two inches wide around cell, above level of stock trunk floor. Firewall must be between driver and fuel cell. All cell mounts must be steel, attached to frame/cage. No adjustable fuel cell mounts. Fuel cell must be in a steel container. Fuel cell vents must have check valves. Fuel lines through driver compartment must run through metal pipe or metal conduit. No fuel filters in driver's compartment.
5. BATTERY - One 12-volt battery only, must be in a marine-type case securely mounted to frame or roll cage in a metal frame behind the seat or in trunk area.
6. TIRES AND WHEELS - 1. Stock (OE) 205/75, or 205/70, 14-inch, or 15-inch passenger tires. All four tires and wheels on car must be same size. Tubes strongly recommended in rear tires. Tires must be inside body. No mud, fancy, exotic, trick gumball tires allowed. No softening, conditioning, siping, grooving, grinding or sanding allowed. No stock wheels. Must be factory rally or racing wheels. No mag wheels allowed. Maximum seven-inch steel wheel. One-inch lug nuts required.
7. FRAME - Frame must match body. 109-inch wheelbase minimum for unibody cars, 107.5-inch minimum for full frame cars - no more than one inch difference from side to side. Frames may be "X" braced. Rear of frame behind rear tires, from a point no further forward than one inch behind the factory seam, may be replaced in stock location with two-inch by three-inch steel tubing with .095-inch wall thickness. Factory seam must remain visible. Must replace the same length material removed. Unibodies must be tied - rear frame to front frame. No station wagons, convertibles, front-wheel drive, four-wheel drive or rear engines. Bumpers must be in stock location. Front and rear bumpers must be capped with minimum 16 gauge steel to fender the width of the bumper. No reinforcement of bumpers. Maximum one inch wide by two inch tall steel rub rails bolted flush to body from fender well to fender well and rear quarter panel. Lexan type also allowed.
8. SUSPENSION - Must be original type suspension and match the frame. No alterations to any suspension part or suspension mounting brackets. Center of rear lower control arm bolt hole must be 2 ˝ inches from bottom of housing No rear independent suspension allowed. Steel springs only. No add-on quick steer boxes. No remote reservoirs on power steering pumps. No spacers, lumber, or chains allowed. All coil springs must be minimum 4 ˝ inch outside diameter and be non-progressive. Spring perch heights must be the same on both sides. For 1978-1987 GM mid-sized metric frame, OEM upper A-frame may be replaced using aftermarket upper A-frame (steel only), must display “IMCA approved” decal on top of rear tube of A-frame; bolt on spindle savers allowed.
9. SHOCKS – One unaltered steel, non-adjustable, non-take apart, OEM-mount shock, in OEM location, per wheel. No coil-over shocks, air shocks, remote reservoir shocks. No Schrader valves, gas relief/refill ports. No coil-over eliminators. Rear OEM shock location is 4.5 inches from bottom of housing to center of bolt hole, and centered on control arm bracket. All four shocks on car may be claimed for $20 each (or claimee may swap shocks instead of the money), counting as one claim. Driver cannot claim shocks and engine in the same event. Refusal to sell shocks will result in loss of all A.C.S. points and money for the night.
10. BRAKES - Master cylinder must be in stock location. Approved OEM brakes on all four wheels must work. No OEM Antilock Brake Systems. No rear wheel disc brakes. No after market brake pedal assemblies allowed. No brake shut-off or bias allowed. No plastic brake lines.
11. BODY - 1960 or newer American made stock passenger automobile with factory steel top. No Camaros, Firebirds or Mustangs. Sunroofs and T-tops must be reinforced and enclosed. All bodies must be approved OEM and be mounted in stock location. Front body mounts must be visible. After market plastic nosepieces and tailpieces will be allowed. No spoilers, wings, skirts, air scoops or anything that alters the stock appearance. No aluminum hoods. Hood must be separate from fenders - no one-piece or tilt front ends. No gutting of hoods or trunks. Trunk floor directly over rear end housing must be removed. No cutting out kick panels. All hoods and trunks must be securely fastened and the back of hood must be sealed off from driver's compartment with metal. Maximum seven-inch metal sun visor may be added to top of windshield opening, only. No external rub rails allowed. All sharp edges, torn fenders and body panels to be repaired prior to next race. Must have a minimum of four windshield bars in front of driver covered with screen. No ballast allowed. Any item deemed as ballast will be required to be replaced. Example: fuel cell straps, fuel cell can, battery boxes, heavy-wall tubing, etc. No gun-drilled, tubular, hollow bolts or studs.
All glass, plastic, upholstery, rear seat, lights, mirrors, and chrome removed. Dash is not to extend more than 24 inches back from center of lower windshield opening.
Dash must be flat except for cowl in front of driver. No other interior tin or covers. All doors must be secured shut (welded, chained, bolted, no rivets) The front inner wheel wells may be removed, but not the rear wheel wells.
12. DRIVE TRAIN - Minimum 2.5-inch diameter steel driveshaft only and must be painted white. All forward and reverse gears must be operational. Transmission must be approved OEM automatic, with original bellhousing and functional torque converter containing a minimum of three quarts of fluid, or approved OEM single disc-type clutch inside an explosion-proof steel bellhousing on manual transmission only. Any steel flywheel allowed with a minimum weight of 16 pounds. No aluminum flywheels. Automatic must have an approved scattershield (may be constructed of quarter-inch by three-inch steel, 270 degrees around flexplate or flywheel. Torque converter must have a minimum 1/8-inch plug. No truck rear ends allowed. OEM or hardened OEM replacement steel axles only. Steel axles only. Nine-inch Ford rear end allowed, but must be mounted like stock rear end for that make and model. Rear end may be welded or mini spool, no full spools. No floater rear ends. Rear suspension must match frame. No electronic or mechanical traction control devices allowed. Minimum gear ratio (highest number allowed) is 5.83.
13. NUMBERS - All cars must be numbered with large, legible numbers on both sides, top and rear panel. Numbers must be in contrasting color from body, in all light conditions. Numbers on side of car to be at least 4 inches thick and 20 inches high. Numbers on top must be at least 4 inches thick and 30 inches high. Recommended that no holographic or reflective numbers be used.
14. Engines are restricted to nine to one compression as determined by a whistler tester.
(A) Steel heads only. No vortec heads.
(B) Flat top pistons only; GM cars - approved steel head numbers are – 014, 195, 267, 330, 336, 339, 388, 393, 441, 445, 454, 487, 493, 545, 598, 624, 642, 709, 799, 813, 862, 881, 882, 920, 991, 993, 997; Ford cars, no after market or SVO heads; Chrysler cars, no after market, W1 or W2 heads, 360 cubic inch heads only. Must be 76 cc heads or larger.
(C) GM approved block numbers are: 3892657, 3914678, 3932388, 3932386, 3956618, 3970000,3970006, 3970010, 3970014, 10066033, 10066036, 14010207, 14010209, 14010287,14016376,14016379. Stroke must match block.
15. ENGINE and CARBURETOR - FOLLOWING RULES APPLY TO ALL ENGINES:
(A) The engine must appear strictly stock for that model and make and in the original mounts. No 400 or larger cubic inch parts allowed. No V6. Stroke must match block. Harmonic balancer may not be altered. Cylinder heads must be unaltered approved OEM. Maximum 360 cubic inches (370 for Chrysler). No porting or polishing or alterations of any kind to heads or intake, disqualification and $100 fine if illegal.
(B) Must have approved OEM cast iron two barrel intake. No headers, must be cast iron exhaust manifolds. No center dump type manifolds. Exhaust must extend past the firewall. Must remain dual exhaust, no crossover or ‘Y’ pipes allowed. No oxygen sensors allowed.
(C) No electrical fuel pumps allowed. Minimum two-core approved steel or aluminum radiator. OEM type steel or aluminum water pumps only. No full roller or roller tip rocker arms. No roller lifters. No stud girdles. Steel or aluminum pulleys allowed. No serpentine belts allowed. Any overflow tubes are to be directed to the ground, between frame rails. Mufflers are recommended. Accumulators and Accusumps must be mounted under the hood. OEM Starter must bolt in stock location. Stock steel accessory brackets only. Screw-in rocker arm studs and guide plates are allowed.
(D) All cars must run a stock two barrel carburetor, no Holley. Fords must run Motorcraft carburetor only. Chrysler and General Motors must run Rochester carburetor only. May remove choke, but no other alterations allowed. (NOTE: Carburetor may be claimed for $50 (or claimee may choose to swap instead of taking the money), following engine claim procedure. Penalty for refusal will be loss of points and money for that night. Carburetor or engine, but not both, may be claimed by single eligible driver on any given night.) Conventional air cleaner housings only. No top flow air cleaner housings, cold air boxes or air cleaner duct work allowed.
(E) All cars must have the capability of starting without being pushed or pulled. All cars must have capability to join lineup on demand, unaided, or go to the rear of that race.
(F) Engine must be in OEM location, using any steel engine mounts (no mid-plate allowed)
NOTE: During engine claim, exhaust manifold must be pulled and heads inspected prior to transfer of engine to claiming driver. If, at this time, heads are found illegal, claimed driver is disqualified and suspended from all A.C. S. sanctioned events until such time as a $250 fine is paid, for first offense. Claimer has the option to accept or decline the engine. If claimer declines, claim is not charged against him/her. Second offense penalties will be same as engine refusal, loss of all A.C. S. points, 30-day suspension and $1,000 fine.
16. ENGINE CLAIM
(A) $325 cash claim on engine, $25 of this goes to wrecker for pulling engine. (Tech man cannot make change.)
(B) Claim does not include - 1. flywheel, 2. clutch, 3. pressure plate, 4. bellhousing, 5. valve cover breathers, 6. carburetor, 7. starter, 8. motor mounts, 9. sending units and switches for oil pressure and water temperature, 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. exhaust manifold.
(C) First four position finishers must report directly to claim area and are subject to engine claim by any other driver finishing fifth on back in feature. Failure to report directly to claim area will result in disqualification and loss of money and points for first infraction (engine is still claimable); will be treated as engine claim refusal for second infraction. Any driver lapped by the fourth place car is not eligible to claim. Driver allowed one claim ONLY per event, regardless of outcome of that claim. If two drivers claim the same engine, a drawing will be held to determine the eligible claimor. If three or more drivers claim the same engine, the claim will automatically become a promoter’s claim. All claimors will place a sealed bid of the price over and above $325 that they are willing to bid for the engine. The highest bidder will become the eligible claimor. At that point, the claimee can choose to take the $325 or swap engines with the claimor. All money over and above the $325 will go into the class year-end point fund.
Should the first eligible driver withdraw his claim, the next qualified driver will be awarded the engine. The claim is not charged to those drivers not awarded the claim.
(D) Driver making claim must drive his race car immediately after finish of feature, under its own power, directly to claiming area. Highly recommended that only involved drivers and officials be allowed in claiming area.
(E) Claims must be made immediately following feature race, and claimed engine must be completely removed within a reasonable amount of time.
(F) Claims must be made to track official, and $325 cash must accompany declaration of intention to claim.
(G) Only driver may claim engine and only driver may agree to sell or refuse to sell engine. Claimee may trade engines instead of taking the cash. Claimer will pay both wrecker charges.
(H) Refusal to sell forfeits all cash and contingency winnings for feature, any trophies earned in feature, plus ALL A.C.S. points in all claim divisions for the night.
Any driver refusing to sell engine, when claimed within rules, regardless of his reinstatement with A.C.S., loses his right to claim any A.C.S. driver's engine for 12 calendar months from date of claim. Claim is not charged to claiming driver in case of a refusal.
(I) First refusal to sell will result in driver being suspended from A.C.S. competition for two completed events and $500 fine must be paid to return to competition. Second, third, etc. refusal to sell will result in suspension for four complete events and $1000 fine.
(J) Once an engine claim has been made and accepted, the engine is not to be started, under any circumstances. The car is to be pushed to the area where removal will take place. The penalty for starting a claimed engine will be the same as a refusal of a claim. All claimed engines must be removed from car at the track.
(K) The cylinder block may not be altered in such a way as to prevent it from being used in a stock application. Stock approved OEM components must be able to be immediately used in their stock location. Drivers are to be held accountable for any sabotage discovered while pulling the engine, and will be responsible for any and all penalties as a result of any sabotage. Any sabotage discovered to claimed engine will result in driver being suspended from A.C.S. competition for 30 calendar days and until $1,000 cash fine is paid to A.C.S. The claim will be disallowed and the money returned to the claimer.
(L) Claim is in effect opening night for all eligible drivers who competed in at least 2/3rd of the events of the previous year. Driver must have been in competition on opening night plus 2/3rd of the events of the previous year to be eligible to claim the second night. Following that no driver can claim unless he/she has competed at the track the two previous completed events, plus at least ˝ of the events of that season. (Example: if claiming on July 17th must be in competition July 3rd and July 10th , and if that is the 10th night of the year, competed in at least 5 events for the season)
(M) No one driver may claim any other one driver more than once during current calendar year.
(N) During engine removal, if claimee is found to be illegal, claim will continue and claimee will also be disqualified for the event. If claimor is found illegal, claim is voided and not charged against either driver with claimor being disqualified for the event.
(O) Unsportsmanlike conduct during the claim procedure, or while pulling the engine, will result in an immediate $100 fine per person
(P) Any one driver may only have two completed claims of engines, carburetors, shocks, or combination thereof per calendar year
(Q) Driver claiming is not required to return with claimed engine the next time he competes at A.C.S.
(R) Promoter reserves the right to claim any engine, regardless of finish position. If claim is completed, engine will be auctioned and sealed bids will be taken. Claimee will receive $300 and wrecker pulling engine will receive $25. Claimee may pull his own engine and take the $25 pulling fee. All money received in the highest bid exceeding $325 will be put into the hobby stock point fund. All drivers registered to compete on that night of racing will be eligible to bid on engine (including claimee).
17. EIRI- (Except in rare instances) Decisions of officials are final and binding without exception. In some cases, track safety rules may take precedence over NASCAR rules.
All changes and clarifications of rules have been put in red print.