Preface
All equipment is subject to the approval of SMS Officials. You may be assessed penalties including but not limited to: added weight, fines, loss of points, loss of handicapping, and suspension, car parts, components, and/or equipment deemed as not in compliance with these rules. Any car part, component, and/or equipment which does not conform to specifications or tolerances contained in the 2022 rule book or is not otherwise approved by SMS may not be used in competition in 2023.
By engaging in competition at SMS, you hereby agree to have read the 2023 NASCAR Weekly Racing Series rulebook, the 2023 SMS General rulebook and the 2023 SMS Street Stock rulebook.
All 2023 NASCAR Weekly Racing Series (NWRS for Late Model Stock) rules will be enforced for the SMS Street Stocks, when applicable, with the following changes and/or additions (EIRI). SMS Officials decisions regarding rules are final and non-appealable.
You may not compete without a roof, hood, trunk lid, bumpers, fenders, quarter panels, air cleaner or mufflers.
STREET STOCK MISSION STATEMENT
The Street Stock division was designed and created to be an inexpensive way to help competitors develop basic mechanical and driving skills. This division provides a platform to identify and learn the basic skills prior to moving on to more complex competition.
DRIVER ELIGIBILITY- All Street Stock drivers must have an SMS Street Stock driver’s license. Drivers must be a minimum of 14 years of age. Cross division competition will be permitted upon approval and a maximum of 3 times throughout the 2023 season. All cross competition must be approved by Stafford Motor Speedway. See below matrix for allowed cross competition in 2023.
Cross Competition | |||||
Full-Time Division | SS | LLM | SKL | LM | SK |
Street Stock | YES | YES | YES | YES | |
Limited Late Model | NO | YES | YES | YES | |
SK Light Modified | NO | YES | YES | YES | |
Late Model | NO | NO | NO | YES | |
SK Modified® | NO | NO | NO | YES |
DEFINITION OF STOCK- In the following rules you will see the term OEM Stock used. This means Original Equipment Manufacturer. The parts must come on a standard production car. Special “Off-Road” or racing parts are not permitted unless pre-approved. No carbon fiber or titanium engine, chassis or body parts are permitted.
20F- 1 Competing Models
20F- 2.2 Overall Car Weight
20F- 2.3 Added Car Weight
20F- 2.4 Car Weights After Race
20F- 3 Detailed Body Requirements
The body must be stock appearing and be mounted in the stock location on the frame. Steel aftermarket replacement bodies may be used in place of stock. All body panels must be steel. Hood may be steel or fiberglass. No other fiberglass panels are permitted. Lowering, chopping, channeling, or streamlining of any body part (including roof) is not permitted. Stock window openings must be maintained. No aluminum replacement parts unless noted elsewhere in the rules. All exterior chrome trim, ornaments, outside mirrors and door handles must be removed. Replacement body parts must meet SMS templates. Riveted or welded Rocker panels are permitted, but must maintain minimum ride height at all times. Rear of car must maintain a stock appearance. Stock will be determined by SMS Officials.
20F- 3.1.2 Rear Spoilers
Spoiler must be placed in the center (left-to-right) and at the rear edge of the trunk lid. All spoilers are subject to SMS Officials approval.
20F- 3.2 Glass
20F- 3.2.3 Window Net
20F- 3.2.5 Rear View Mirror
20F- 3.3 Dashboard
20F- 3.4 Firewalls
- Front firewall must be in stock location and be made of minimum .031” magnetic sheet steel with all holes covered using magnetic sheet steel a minimum of .031” thickness. The front firewall must extend down to the top of the frame.
- Rear firewall must be made of minimum .031” magnetic sheet steel securely installed over the rear seat back brace and top shelf or “hat rack”, completely closing off the trunk compartment.
- The top shelf or “hat rack” must be positioned horizontal and approximately level and be no longer front to rear than stock.
- The stock floor pan may be replaced with minimum .031” magnetic sheet steel bent similar to the original configuration. No part of the passenger side floor pan may be higher than the top of the frame rail. The passenger side floor pan may come straight across from a maximum height of the top of the frame rail to the transmission tunnel. The floor must be sealed to the bottom of the door on both sides of the car. The rear seat area must seal to the rear firewall.
- The transmission tunnel shape may be altered, however it must remain in original center position (equal distance from frame rails to either side of the tunnel) and within 1-inch of original height. Additionally, the transmission tunnel must remain within 2-inches of stock width.
- Door bars may not be covered on the interior of the car and must be visible for inspection from the inside of the car.
- Closing in of passenger compartment next to or behind driver is not permitted.
Reminder for main cage construction- You must have 4 door bars on each side, with door bars being curved, not straight, as described below in the NASCAR Weekly Racing Series Rulebook
The door bars (#9A & B), on both the left and right sides, must have a minimum of four (4) bars equally spaced from top to bottom that must be welded horizontally between the vertical uprights of the main roll bar(#1) and the front roll bar legs (#2A & B). All door bars must each be a continuous length of tubing. The top door bar on each side must maintain a minimum vertical height of 20 inches from the top of the main frame rails and match up with the intersection of the dash panel bar (#8) at the roll bar legs (#2A & B) at the front and the intersection of the horizontal shoulder bar (#7) at the main roll bar (#1) at the rear. All door bars must be convex in shape except the bottom door bar on each side which may be straight. The door bars (#9A & B) must have a minimum of six (6) vertical supports per side with two (2) equally spaced between each door bar. These supports must be made from a minimum of 1-3/4 inches by 0.090 inch wall thickness magnetic steel seamless round tubing (not numbered but shown in the left side view of Diagrams #3, #4 & #5).
20F- 3.5 Doors
20F- 3.6 Fenders / Quarter Panels
20F- 3.7 Grilles
20F- 3.8 Hoods / Roof
- A Stock OEM steel or an aftermarket fiberglass hood must be used and be in place at all times. Hoods must lay flat and fit the same as a stock hood without bows or bubbles in the center. Hood must be sealed at firewall and windshield.
- Hood must be held closed with a minimum of three (3) quick release pins across the front. Hinges are permitted on the back corners of hood.
- The hood must be solid and can have no holes or functioning air scoops.
- A 2” (maximum) tall non-functioning hood scoop is permitted.
- An OEM stock steel or an aftermarket fiberglass Street Stock roof is permitted. Roof panels must be mounted in stock position the same as the stock production roof. Roof must be bolted to cage at all four corners with at least 5/16” diameter grade 8 bolts. All roofs must be acceptable to SMS Officials. You may not compete without a hood or a roof.
20F- 3.9 Trunks
20F- 3.10 Bumper / Bumper Covers
- The front and rear bumpers and/or bumper covers must be installed in the same location as far as height, width, and depth as a stock factory production bumper.
- Magnetic steel tubing must be used to reinforce the front and rear bumper covers. The tubing must not be exposed and must remain behind the bumper covers.
- The front and rear bumpers/bumper covers must be solid. Holes are not permitted.
- All front and rear bumper covers must be painted the same color as the car including bolts and rivets.
20F- 3.11 Identification
20F- 3.12 Body Templates
20F- 4- General Engine Requirements
SMS 602 CRATE ENGINE As an option, the 602 GM Performance Factory Sealed Circle Track Crate Engine is permitted. The engine is the GM Part Number 88958602 GMR 350/350 Circle Track Engine with no performance modifications. The engine will be inspected, tested and resealed with blue seals by an SMS Official. All engine seals must remain intact and unaltered. Any service work requiring the removal of any seals/ bolts must also be scheduled with and approved by SMS Officials before the seals/ bolts are removed. Tampering with seals/bolts may result in penalties and loss of eligibility of the engine to compete in the Street Stock division. The sealed engine is only available through R.A.D. Auto Machine, the SMS approved service center. The price for this brand new 88958602 engine is $4,600, which includes dealer delivery to our Authorized Service Center, inspection, break-in, dyno service, documentation, and sealing. The Street Stock engine will be sealed with Blue SMS seals. SK Light or LLM engines are not permitted in Street Stock competition. Please call R.A.D. Auto Machine (413-583-4414) or email the SMS technical staff at tech@staffordspeedway.com with any questions.
20F- 5.1 Engine Location
- Engine must be in the stock location for a V8 in the chassis being run. Stock engine location is when the distance between centerlines of the forward most fuel pump to engine block mounting bolt and the upper idler-arm to frame mounting bolt measures 8.75” inches +/- .25” inch, with all bolt holes being in Stock OEM location.
- The front centerline of the crankshaft must be no less than 13- 3/4 inches from the ground with the car’s frame set on six inch (6”) high blocks under all four outer corners of the frame.
20F- 5.10 Carburetor
- Body of carburetor and metering block: No polishing, grinding, or reshaping of any part. Drilling of additional holes or plugging holes is not permitted.
- The choke may be removed, but all screw holes must be permanently sealed.
- Choke Horn: Choke horn may not be removed.
- Boosters: Boosters may not be changed. Size or shape must not be altered. Height must remain standard.
- Venturi: Venturi area must not be altered in any manner. Casting ring must not be removed.
- Alterations to allow additional air to be picked up below the opening of the venturi such as altered gaskets, base plates and drilling holes into the carburetor will not be permitted.
- Base Plate: Base plate must not be altered in shape or size.
- Butterflies: The stock Holley 4412 or Stainless Steel Holly part #346 butterflies must be used. They may not be thinned or tapered. The Butterflies must remain as manufactured and must maintain the Holley production tolerance thickness of .0438” to .0398”. Idle holes may be drilled in butterflies. Screw ends may be cut even with shaft, but screw heads must remain standard.
- Throttle Shaft: Shaft must remain standard and must not be thinned or cut in any manner.
20F- 5.10.2 Carburetor Adapter, SMS 602 Crate Engine
One standard gasket per side, maximum gasket thickness of .075” permitted.
Alterations of any kind to the adapter plate are not permitted.
20F- 5.12.1 Carburetor Air Filter / Air Filter Housing
- Only a round dry type paper air filter element maintaining a minimum 12 inches and maximum 14 inches diameter is permitted. The air filter element must maintain a minimum of 1 ½” inches, maximum three and a half (3.5”) inches in height. All air must be filtered through the element.
- Only a round, metal filter housing (top and bottom) is permitted. The top and bottom of the air filter housing must be solid with no holes. A maximum of one (1) inch lip is permitted from the air filter element to the outer edge of the air filter housing top and bottom. The air filter housing carburetor mounting ring must have only one (1) round hole, a minimum of five (5) inches in diameter. It is permissible to attach a shield to the front area of the air filter housing up to a maximum of one half of the air filter circumference. The shield must not be higher than the height of the air filter element. The air filter housing metal top and bottom must be of the same diameter. The air filter housing must be centered and sit level on the carburetor. Air induction, ducts, baffles, tubes, funnels, or anything that may control the air entering inside of, or between the air filter and carburetor is not permitted.
- The bottom of the air filter element must measure within one (1) inch of the carburetor’s top flange. A spacer may be used between the carburetor and the air cleaner so long as the one (1) inch specification is not exceeded.
- No part of the air filter or air filter housing may protrude through the hood.
You may not compete without the air filter and air filter housing in place.
20F- 6.1 Ignition System, SMS 602 Crate Engine
- Adjustable timing controls are not permitted.
- Retard or ignition delay devices are not permitted.
- An MSD #8728 or #8727CT external RPM limiter with a 6,300-RPM chip / setting is mandatory. The violet wire of the MSD #8728 or #8727CT must be cut back flush to the unit’s housing. The green and the white wires of the MSD #8728 or #8727CT must run directly to the coil negative. The MSD #8728 or #8727CT must be mounted on the engine side of the firewall in plain view. SMS Officials may require the replacement of the RPM chip with a track issued chip at any time during an event. RPM limiters must be fully functional and operational at all times.
20F- 6.4 Starter
20F- 6.5 Battery
20F- 6.7 Accessories
20F- 6.7.1 Radios
Track Frequency Channel– 461.13750 UHF
Waddell Communications www.waddellcommunications.com 860-573-8821
20F- 6.7.2 Transponders
MYLAPS AMERICA
www.mylaps.com
32 Highlands Parkway Suite 104
Smyrna, GA 30082
Tel 678-816-4000
20F- 7 Engine Cooling System
20F- 7.1 Water Pump
- A Stock OEM type pump must be used. Electric pumps or the combination water pump/alternator units are not permitted.
- Any V-Belt or serpentine belt/pulley system is permitted. Cog belts or pulleys are not permitted. Pulleys must be steel or aluminum.
20F- 7.2 Fan
20F- 7.4 Radiator
- An OEM type radiator must be used in the stock location.
- All cars must be equipped with an approved overflow catch can under the hood by the right front fender. The overflow hose coming out of the catch can must run and up through a fitting in the cowl, at the base of the windshield on the right side.
20F- 8 Engine Oil Specifications
20F- 9 Engine Exhaust System
- Stock OEM exhaust manifolds or Schoenfeld # 185 header must be used.
Headers may not be modified, other than foe interior or exterior coatings.
Ford engines must get header approval by SMS Officials prior to competition. - The exhaust header flange must mount directly to the cylinder head with no spacers between the flange and the cylinder head.
- The header collector must be used as supplied and may not be modified.
- Exhaust pipe must be reduced from 3” to 2 ½” before entering muffler. The pipes after the muffler may have a maximum diameter of 2 ½ inches must run to within twelve (12) inches of the rear axle housing, then turn down a minimum of 45 degrees. Pipes may not exit out the side(s) of the car. Both exhaust pipes must be independent with no connection between them.
- LOBAK # RCM 25-12-25 or Moroso #94050 mufflers must be used and are required at all times. Modifications or repairs of any type are not permitted on the muffler. Both muffler flanges must be intact. Stainless steel mufflers are not permitted. Mufflers must be removable for inspection.
- Thermal wrap is not permitted anywhere on exhaust system.
- Only one muffler and exhaust pipe per side of car is permitted.
- The exhaust system is subject to approval by SMS Officials.
NOTE: The life expectancy for all mufflers is two years. Each team is responsible for inspecting their mufflers to insure they are not illegal due to wear. A muffler will be deemed illegal if it is missing one or more of the internal baffles. You may not compete without the mufflers.
20F- 10 Engine Drive Train – Flywheel And Clutch
Pressure Plate- OEM stock type 10.5” steel pressure plate must be used. See weight requirement below.
Clutch Disc- OEM stock type 10.5” steel full 360 degree disc or Magnus part # 384152F and 384152C must be used.
Pressure plate & clutch disc combined minimum weight – 16 lbs. (fasteners not included).
Clutch disc minimum weight 2.5 lbs. and a maximum weight of 3.8 lbs. (fasteners not included).
Drilling or lightening of any part is not permitted. Solid magnetic steel fasteners must be used. An OEM stock or aftermarket clutch pedal may be used. The pedal and components may be steel or aluminum. A hydraulic clutch bearing, hydraulic slave cylinder, or mechanical linkage may be used. All components are subject to SMS Officials approval.
20F- 10.3 Bell Housing
20F- 10.4 A – Automatic Transmission Option
Torque Converter
- Full size stock torque converter for your year/make/model must be used.
- Torque converter must be operational. Any alteration that may serve to “lock” the torque converter at any time or in any way is not permitted.
- Torque converters of less than 11 inches in diameter are not permitted. Torque converters must have a retail price of less than $325.00.
20F- 10.4 B- Manual Transmission Option
- Only OEM production stock 3 & 4 speed transmissions may be used. Top loader transmissions are not permitted. Gear ratio must be of stock OEM production, with 2nd gear being a 1.50 to 1 ratio.
- Only cast iron housings are permitted. Aluminum or magnesium transmission housings are not permitted.
- Only OEM type, steel, angle cut forward gears are permitted. Square cut forward gears are not permitted.
- All forward and reverse gears must be in working order, and they must be operational from inside the driver’s compartment. All transmissions must have a constant engagement of the input shaft with gear and countershaft with cluster gears.
- Five-speed transmission, with gears removed are not permitted.
- Quick change transmissions are not permitted.
- Machining or lightening of any internal rotating or non-rotating parts including gears, shafts and case is not permitted. Gun drilled transmission shafts are not permitted. Welding on any internal part is not permitted.
- Additional or different from OEM bearings other than the tail-shaft, which may have roller bearings, are not permitted.
- Auxiliary, over or under drive transmissions are not permitted. High gear must have a ratio of 1 to 1, 2nd gear must have a ratio of 1.50 to 1, and no other forward gear may have a ratio higher than 1.20 to1. The shifter and all of its components must be made of steel or aluminum.
20F- 10.5 Driveshaft
- Drive shaft, universal joints, and yoke must be magnetic steel and be similar in design to the standard production type. The drive shaft must be made of one-piece magnetic steel and must either 2-3/4 inches or 3 inches in diameter.
- Two (2) 360 degree solid magnetic steel brackets with no holes or slots, not less than 2 two (2) inches wide and ¼ inch thick, must be placed around the drive shaft. The front bracket must be welded to the rear suspension crossmember and the rear bracket must be welded or bolted, with a minimum of two 3/8-inch diameter bolts on each side, to the horizontal tunnel bar (#6).
- All drive shafts must be painted white.
Gear Rule
OP-20F- 10.6 Gear Rule
You may run a 3.23 / 3.25 (GM 7.5″ / Ford 9″) numerical rear gear along with a 1.50 2nd gear ratio transmission, or you may use a 4.56 (GM or Ford) numerical rear gear with a 1:1 3rd gear ratio transmission. No other options or combinations are permitted.
20F- 10.7 Wheels
20F- 10.8 Tires
TIRE INVENTORY- T-B-D for 2023 Season
Each tire will carry a special bar coded serial number. The legibility of the bar code is the sole responsibility of the team. Drivers must pick up their Tire Inventory card from the Handicapping / Sign in booth and enter the barcode serial number of the tires they wish to use. Each tire barcode that is entered on the tire sheet will use one of your credits. The Tire Inventory card will be filled out and turned in to the Tech Center tire window each week prior to the scheduled drivers meeting. Drivers that do not turn in the Tire Inventory Card on time may be penalized. Edits to the tire inventory card after it is turned in is not permitted.
Drivers that have non-inventoried tires on their car during qualifying or feature events will be penalized.
In the event a driver changes cars for qualifying or feature racing, their tire inventory must accompany them to the new car (EIRI).
The amount of extra tires allowed for longer distance feature events will be determined by SMS Officials.
If a tire cannot be identified, it will be considered illegal.
SMS Officials may change or amend these rules at any time.
20F- 10.8.1 Physical Requirements
NOTICE: Participants specifically agrees that he/she acknowledges that it is illegal to soak or treat racing tires and that said soaking or treatment of racing tires is against EPA regulations and further contains carcinogens and hazardous material which are unfit for his/her health and the health of all competitors and spectators. Any participant found violating the rule will be subject to suspension. JTR Eagle PPM Tester will be set at a fixed level and will be strictly enforced throughout the 2022 season.
20H- 11.1 Stock OEM Frames
- The Hamm’s Welding front frame section (# TBD) may be installed from the front edge of the front spring pocket forward that incorporates the correct OEM steering box, idler arm and sway bar mounting locations. The front frame horns may be replaced with 2” X 3” .083” square tubing from the forward most ½” measuring hole to the front bumper. No other part of front frame rails can be replaced with tubing. On the stock front sub frame a minimum opening may be cut into the front of the spring pocket to access the adjustable spring spacer.
- The front cross member must remain unaltered, Stock OEM.
- Rear frame rails may be replaced with 2” x 3” .083” magnetic steel square tubing from the rear edge of stock upper cross member back, only if following stock configuration height, width, and length. Optionally the replacement rear frame rails may extend parallel rearward maintaining a minimum width of the stock frame rails width at rear most edge of the upper cross member. Both the Stock OEM cross member ahead of the rear axle and Stock OEM upper cross member must be used.
- No offset or shortening of frame rails.
- Frames must measure within a 1/4inch of all factory specifications for year/make/model used. All measuring cups or holes must remain unaltered.
- Tubing of a size and length that will not protrude from the stock frame may be located inside the driver’s side frame rail. All roll cage bars normally attaching to the drivers side frame rail must be welded directly to the supplemental tubing.
- Tubing may be utilized as a replacement for the stock transmission cross member. Any non-stock replacement transmission cross member must be located perpendicular at 90 degrees to the stock frame rails and no further towards the rear of the car than to have the rear edge of the tubing even with the rear edge of the transmission hosing.
- Additional X-tubing may be added so long as the tubing connects to the cross member and is not one continuous piece running from corner to corner of the stock frame. The X-tubing must attach within the two corners of each frame turnout. The X-tubing may not extend past any of the frame turnouts and may not be attached to the perimeter frame rails short of the frame turnouts.
FORD FRAMES- Ford full-size frames, (LTD, Crown Victoria) 1979 and newer may be shortened to 108” wheelbase. Frame must be shortened in center section only using the same area on both sides. Any Fords that are shortened to 108” wheelbase are allowed to use the Ford Thunderbird body from the same era.
20H-11.2 Optional Tubular X-Y-G Frames
Main Frame
- A tubular magnetic steel “perimeter” frame must be used. Offset frames are not permitted. The main frame side rails must be parallel and be an equal distance from the centerline of the frame. The main frame side rails must be Stock OEM “C” channel rails, Hamm’s part # GHC-664235 fabricated “C” channel rails, or fabricated as described herein: the main frame side rails must be the same size (left and right, height and width), constructed using a single tube, and must be magnetic steel box tubing three (3) inches in width by four (4) inches in height with a minimum wall thickness of not less than 1/8 inch, meeting ASTM A-500 specification. The main frame side rails start at a distance of 20 inches forward of the rear axle centerline and extend forward a length of 66 inches. When measured from the outside of the left frame rail to the outside of the right frame rail, a width of 54 inches, plus or minus (+/-) ½ inch, must be maintained. The distance from the outside edge of the main frame side rails, left and right, must be the same, measured from the centerline of the tread width, front and rear.
- Sub-frame kick outs must be constructed using a single tube and must be magnetic steel box tubing three (3) inches in width by four (4) inches in height with a minimum wall thickness of 1/8 inch meeting the ASTM A-500 specification. The sub-frame kick-outs must turn in 90 degrees to the main frame side rails and be welded to the inside ends of the main frame rails. The open ends of the sub-frame kick-outs must be closed by welding caps on the ends or bolting weight containment caps. The distance from the front of the front kick-out to the rear of the rear kick-out must be 66 inches. The front kick-out must measure 86 inches from the rear axle centerline.
- A cross member constructed of magnetic steel box tubing, two (2) inches by two (2) inches with a minimum wall thickness of 0.083 inch meeting the ASTM A-500 specification, must be welded between the main frame side rails at a distance of 48 inches from the rear axle centerline.
- All frames must have diagonal cross bracing constructed of a minimum one (1) inch by one (1) inch by 0.065 wall thickness steel tubing.
- All cross members and diagonal bracing must be installed flush to the top of the main frame side rails. The centerline of cross members may be notched a maximum width of 12 inches for driveline clearance. No part of the cross members or diagonal bracing may extend lower than the main frame side rails.
- If the optional tubular metric frame is used, the center to center dimension of the main roll bar #1 and the rear axle must be a minimum of 23-1/2 inches.
Rear Sub-Frame
- The rear sub-frame rails must be configured and attached in the same location on the left side and right side to the sub-frame kick-outs four (4) inches in from the outside edge of the main frame rails. The rear sub-frame when measured from the outside edge of the left sub-frame rail to the outside edge of the right sub-frame rail must measure 46 inches, and this width must be maintained for the entire length of the sub-frame. The rear sub-frame must angle rearward and upward at an angle between 45 degrees and 50 degrees to a maximum height of 22 inches from the ground (on five (5) inch blocks), then angle rearward parallel to the main frame rails a maximum distance of 16 inches, then angle down to a minimum height of 11 inches and a maximum height of 14 inches from the ground. The rear sub-frame must be constructed using magnetic steel box tubing, two (2) inches in width by three (3) inches in height, with a minimum wall thickness of 1/8 inch and must be similar in design and configuration to Stock OEM rear kick-ups.
- The rear sub-frame tail section must extend rearward at a minimum height of 11 inches and a maximum height of 14 inches, to a maximum length of 38 inches from the centerline of the rear axle. The rear sub-frame tail section side rails must be parallel to the main frame side rails and have a minimum length of 24 inches. The rear sub-frame tail section must be constructed using magnetic steel box tubing two (2) inches in width by three (3) inches in height with a minimum wall thickness of 0.083 inches.
- The rear sub-frame must incorporate the mounting locations for the rear springs, shock absorbers, 4 link, and fuel cell, ending with a cross member constructed of magnetic steel box tubing two (2) inches in width by three (3) inches in height with a minimum wall thickness of 0.083 inches a maximum length of 38 inches from the centerline of the rear axle.
- A reinforcement bar, made from round magnetic steel tubing, minimum 1-1/2 inches in diameter with a minimum wall thickness of 0.083 inches, must extend below the rear sub-frame section behind the fuel cell. This reinforcement bar must be as wide as the rear sub-frame rails and extend as low as the bottom of the fuel cell with two (2) vertical uprights evenly spaced between the sub-frame rails and attached to the rear cross member. Two (2) support bars, one (1) located on each corner, must angle upward and be welded to the rear sub-frame side rails. (See the Construction Guidelines in the rear pages of the Rule Book).
- Weight containers, if used, must only be attached to the inside of the frame rails and must not be lower than the bottom of the frame rails.
- The back of the rear sub frame from the center line of the rear end may be mitered to conform to the rules stated above. This is the only mitered section allowed, excluding the front radiator support.
FRONT SUB-FRAME
All vertical (height) dimensions listed are measured with the frame at 5” ride height at all 4 corners. The front sub-frame must be constructed by the following guidelines.
- A GM-METRIC type front steer tubular front sub-frame must be constructed using two (2) inch wide by four (4) inch high magnetic steel tubing with a wall thickness of meeting ASTM A-500 specifications. The front sub-frame rails must be parallel to each other both vertically and horizontally. The front sub-frame rails must be parallel both vertically and horizontally to the mainframe rails from the Stock OEM shock hole location forward. All front steer assemblies must maintain a dimension of 31 inches from the center of the left side frame rail to the center of the right side frame rail at a point from the Stock OEM shock hole location extending forward in front of the steering assemblies. Spring bucket may be cut into left side and right side frame rails. Top of spring buckets will maintain a vertical height of 15 ¼ (+/-) ½ inch. Stock OEM shock hole location will maintain a centerline distance of 33 ½ (+/-) ½ inch measured at top of spring bucket from left side to right side and be located equal distance from centerline left and right. Note: a measurement and angle for the upper A-frame mounts will soon be inserted. A distance of 21 inches (+/-) ¼ inch must be maintained from the front frame kick-outs forward to the Stock OEM shock hole location centerline. The front sub frame rails may angle outwards and downwards from the Stock OEM shock hole location to the front frame kick-out to a maximum distance of 41 inches. If frame rails are angled outward. a wishbone made from round magnetic steel seamless tubing 1 ½ inch by .083 minimum wall thickness meeting ASTM A-519 specification must extend from dash bar #8 to an area at the rear lower a-frame mount and continue to connect at an intersection of roof support bar #12 and diagonal bar #7A extend rearward a distance of 34 inches than angle down 30 degrees to the front frame kick-out. The front frame extensions using two (2) inch wide by three (3) inch high minimum wall thickness of 0.083 inch magnetic steel tubing meeting ASTM A-500 specifications must angle out and forward and extend a distance of twelve (12) inches forward of the forward most top steering box bolt to a minimum distance of 33 inches from the center of the left side frame rail extension to the center of the right side frame extension. This forward top steering box bolt will be a horizontal distance of 39 inches from the front frame kick-out and a vertical height of 15 inches (+/-) ½ inch (Steering box bolt location will be inspected with a fixture that will read zero (0) degrees with the frame on six (6) inch ride height blocks). At a point four (4) inches in front of the top steering box bolt a two (2) inch wide by four (4) inch high magnetic steel tubing with a minimum wall thickness of 0.125 inch meeting ASTM A-500 specification must be a distance of 24 ½ (+/-) 1/8 inch must be maintained to the center of an O.E.M. three quarter (3/4) inch pin boss located on the mainframe centerline at the front of the front sub-frame cross member. The O.E.M. pin boss will be used for locating inspection fixtures. The front sub-frame cross member must be mounted at the centerline of the front sub-frame at a 90 degree angle against the back of the ¾ inch pin boss and be constructed using two (2) inch high by four (4) inch wide magnetic steel tubing with a minimum wall thickness of 0.125 inches meeting the ASTM A-500 specifications. A minimum thickness of one hundred thousandths (0.100) 12ga.magnetic steel must be used to construct the remainder of the front sub-frame cross member. The front mounting points for the front lower a-frames must be constructed using a minimum 3/16 inch thickness magnetic steel. The front mounting points for the front lower A-frames must be 9 3/8 inches, measured from the centerline of the front sub-frame to the centerline of the mounting bolt at the front side of the mount and a vertical height of seven (7) inches (+/-) ¼ inch. The rear mounting points for the lower A-frames must be constructed using a minimum 3/16 inch thickness magnetic steel. The rear mounting points for the lower A-frame must be 13 inches (+/-) ¼ inch measured from the centerline of the front sub-frame to the centerline of the mounting bolt at the rear side of the mount and the vertical height will be 6 7/8 inches (+/-) ¼ inch. Adjustable insert slugs may be used on the rear mounting bolt to maintain a distance of 22 inches (+/-) ½ inch from the center of the lower ball joint to the leading edge of the mainframe side rail and kick-out. A ½ inch round by 15 inch long solid steel pin must pass freely through these points during inspection. When measuring either the right side or left side the distance from the centerline of the bottom ball joint to the centerline of the sub-frame must be equal. The mounting plates for the upper A-frames must be welded to the top of the sub-frame rails and be parallel with the centerline of the sub frame rails. A distance of 37 inches will be maintained from the top idler arm bolt centerline to the front frame kick-out with a vertical height of 14 inches (+/-) ¼ inches. The GM-METRIC tubular front sub-frame must weigh a minimum of 95 lbs. A bare front sub-frame must be submitted to track officials for weigh in and approval. Front sub-frame must be acceptable to SMS Officials before it can be used in competition
NOTE: The tubular front sub-frame may not have jacking bolts, and the shock hole location and the upper a-frame mounting points must remain in the Stock OEM location.
Approved front sub-frames (front clip):
Stock OEM Metric
Hamms Welding P/N GHC-54108, (mandrel or mitered)
Hamm’s Welding P/N GHC-54108-Z61 (mitered w/ crossmember change)
Johnson Chassis P/N JCI 09-011
20F – 12.1 Coil Springs / Spring Mounts / Jacking Bolts
Front Coil Spring– Must meet the following:
Manufactured from round magnetic steel wire.
Have consistent wire diameter from top to bottom.
May not exceed $110 in retail advertised price.
All the coils must be active.
Must maintain consistent spacing between coils.
Must be 8-1/4” to 11” in free height.
Must be 5-1/4” to 5-3/4” in outside diameter.
Rear Coil Springs- Must meet the following:
Each rear coil spring may not exceed 400lbs. in rate.
The spring will be checked for rate through several inches of travel, and must not be higher than 400 lbs per inch (+/-).
The spring will be checked for rate through several inches of travel, and must remain at the 400lb. rate (+/-) throughout the travel range.
Manufactured from round magnetic steel wire.
Consistent wire diameter from top to bottom.
May not exceed $110 in retail advertised price.
All the coils must be active.
Must maintain consistent spacing between coils.
Both coil ends closed and ground.
The closed ends of the coil spring must not have a gap larger than 1/8”.
Must be 10” to 15” in free height.
Must be 4-3/4” to 5-1/4” in outside diameter.
20F- 12. 2 Sway Bars
- One Stock OEM sway bar may be used in the front and/or rear. The sway bar must be magnetic steel, one-piece, and can be no larger than 33 millimeters (1.299”) in diameter. The sway bar must be used as it is manufactured. Modifications to the sway bar are not permitted. Front sway bar must mount under the frame, in the stock location, and attach to the lower a frames in their stock location.
- Bump pad configurations are not permitted. Splined sway bars and arms are not permitted.
- Rubber sway bar bushings may be replaced with metal bushings or eye/lollipop type mounts.
- Heim joints (spherical rod ends) are not permitted.
20F- 12. 3 Shock Absorbers
Brand | Front | Rear |
Carquest | 64600 | 64604 |
KYB | KG-4513 | KG-5548 |
Monroe SSF Series | N/A | 12475-6-7-8 |
Monroe SensaTrac | 5840 | 5802 |
Doetsch | 0101 | 0102 |
AFCO | 1020 | 1030 |
AFCO | 1021 | 1031 |
AFCO | 1022 | 1035 |
Bilstein | AK1043 | AK1044 |
ProShock | SS-100 | SS-201 |
QA1 | EC1956P | EC1685P |
For non-GM cars, you must use the same series shocks from the above list and obtain prior written (email to tech@staffordspeedway.com) approval.
20F- 12. 4 A-frames
- Upper & lower A-frames must remain stock OEM & unaltered for year/make/model. A-frames may not be changed from side to side. The upper and lower a-frames must be installed in the stock OEM location / stock OEM mounting points.The following upper a-frames are permitted:
*Stock OEM upper A-frames for the chassis year/make/model.
*Speedway Motors P/N 91031134L and 91031134R with steel cross shaft.
*ALLSTAR P/N ALL57831 and ALL57830 with steel cross shaft.
*UB Machine P/N 14-0809-5R and 14-0829-6L with steel cross shaft.
No modifications may be made to the upper A-frames.The following lower a-frames are permitted:
*Stock OEM lower A-frames for the chassis year/make/model.
*X-Y-G aftermarket stock geometry replacement for chassis year/make/model.
*Hamm’s Welding GHC-1425727 (L-R)
*Hamm’s Welding GHC-1425727-10deg.-R
*Johnson Chassis JCI-9-02-001 (L-R)
The only modification permitted to the lower A-frame is the following: the flat surface of the right front ball joint helix may be cut and moved 10 degrees for ball joint bind clearance purposes only if a Chrysler screw-in type ball joint is used. - Lower ball joints may be replaced with “pressed-in” stock type extended lower ball joints in Stock OEM position or with standard factory Stock OEM production Chrysler screw-in type or standard factory Stock OEM production Chrysler screw-in type direct replacement ball joints in the stock location on the A-frames.
- Rebuildable or serviceable ball joints are permitted. Adjustable and “mono” ball joints are not permitted. Ball joints must be stock appearing, heavy-duty magnetic steel construction and must be acceptable to SMS Officials. The ball joints must not have any adjustment with the exception of a free play adjustment in the housing for the ball and socket. The total length of the ball joint pin from the top of the ball joint housing to the top of the pin must not exceed 3.375 inches for both upper and lower ball joints.
- Upper ball joints must be stock OEM. Shimming of the upper ball joint is permitted.
- Only Stock OEM type steel, zero offset upper control arm cross shafts are permitted.
- Upper & lower A-frames must use the Stock OEM rubber bushing or an aftermarket polyurethane bushing. Bushings must have zero offset (be concentric). Bushing hole location may not be altered.
- All A-Frame mounts must remain in Stock OEM location.
20F- 12.5 Spindles And Hubs
GM Stock OEM Metric or Camaro steel spindles or the QA1 part #’s 9056-104 or 9056-105 must be used.
The Coleman two piece steel stock Metric replacement safety hub #16798 and rotor #140-753, or the Camaro hub #20651 and rotor #130-750-2, and the Mittler Bros. part # 1400-5X5S hub are permitted (and recommended). No modifications are permitted to the spindle or hub assemblies. Low Drag components are not permitted. Two standard steel wheel bearings, a wheel bearing seal, a torque nut and a standard nut locking mechanism are the only components permitted on each spindle/hub assembly.
20F- 12. 6 Track Width
Maximum track width measured outside the tire bulge at wheel center height is 72¼ inches. Metal wheel spacers are permitted to utilize the maximum allowable track width. The wheel spacers must be the same thickness left and right, however, the front and rear do not have to match.
20F- 12.8 Wheelbase
GM Metric chassis or XYG must measure 108” +/- ¼”. All other chassis year/make/model must be +/- ¼” from factory listed wheelbase.
20F- 12.8.2 Ground Clearance
A minimum of six (6) inches of ground clearance must be maintained at all times measured at the lowest point of the frame rail. No part of frame, body, sheet metal or bumper may be lower than 6” from ground. All ground clearance requirements are with the driver in the car.
20F – 12.9 Body Height
Minimum height for the roof is 51 inches measured 8” rearward from the centerline where the windshield and roof meet.
20F- 12.11 Weight Transfer Devices
The only weight jacking or transferring devices allowed on the car are standard spring pocket jacking bolts, front and rear. Upper rear spring perch may be trimmed only enough to accommodate new pocket. No other types of weight transferring or jacking devices may be used. Handles must be removed from jacking bolts before the car is moved.
20F – 13 Steering Components
All steering components must be acceptable to SMS Officials and meet the following minimum requirements:
- All cars must be equipped with a magnetic steel steering shaft.
- All steering boxes must be mounted in the stock location and the stock position at an angle of not less than 10 degrees on GM type front sub-frames. Any means of raising or changing the steering box position will not be permitted.
- Tie rods, drag links, pitman arms, idler arms, and component parts must be heavy duty magnetic steel. Holes and/or other modifications in steering components that, in the judgment of SMS Officials, have been made with the intent of weight reduction will not be permitted.
- An OEM centerlink and idler arm, or a commercially manufactured non-adjustable stock type steel replacement is permitted.
- The center top of the steering post must be padded with at least two (2) inches of resilient material acceptable to SMS Officials.
- A quick-release steering wheel coupling with a metal housing, acceptable to SMS Officials, must be used. The steering wheel coupling should meet the SFI 42.1 specification.
- Rack and pinion steering will not be permitted. All steering components must be made of magnetic steel including but not limited to drag links, pitman arms, idler arms, steering arms, and steering boxes.
- Only magnetic steel spoke steering wheels will be permitted.
- The power steering pump must be mounted and driven off the front of the engine.
- All steering boxes must be constructed of magnetic cast steel.
- The use of two (2) universal joints, a minimum of 12 inches apart, in front of the firewall and a collapsible steering section in the steering shaft is recommended and must be acceptable to SMS Officials.
- Stock type steering box must be used. Rack and pinion steering will not be permitted.
- Inner tie rod: OEM type tapered fit, non-threaded pin, magnetic steel tie rod end must be used on the inner tire rod. Outer tie rod: OEM type tapered fit, non-threaded pin, magnetic steel tie rod end must be used on outer tie rod end. Tie rod sleeve: Stock OEM type or aftermarket radius rod (steel or aluminum) may be used. Tie rod sleeve bolts and/or jam nuts must be magnetic steel.
20F- 13.1 Steering Wheel
A NASCAR approved quick release steel coupling on steering wheel is mandatory. Center-top of steering wheel must be padded with at least 2” resilient material.
20F- 14 Brakes
Stock OEM type hydraulic brakes must be used- disc front, disc or drum rear. Front and rear calipers must be Stock OEM type steel, single piston calipers. Two-piece steel rotors may be used, no aluminum hats or hubs. Only magnetic cast iron or cast steel round circular rotors permitted. Front rotors must be vein type with a minimum thickness of 1”, rear rotors must have a maximum thickness of 1”. Rotors cannot be drilled, slotted, or grooved. Only factory dust clean out allowed. The brake rotors must be bolted to the hubs. Floating brake rotors are not permitted. All rotors and brake components subject to SMS Officials approval. Other brake components may be utilized from different year/make/models. One aftermarket hydraulic bias adjustable unit may be used. The aftermarket unit must proportion the front/rear bias only, and it may be accessible by the driver in the cockpit. Racing type brake pedals and master cylinders may be used. Master cylinder(s) must be single stage design.
20F- 14.2 – Brake Cooling
The Ultra Cool steel fan, part # LMBFS5-625 L or R may be used, one on each front wheel/hub assembly. No other brake coolers, blowers, or fans of any type are permitted. Additionally, coolers, blowers, or fans of any type are not permitted anywhere on the car unless specified elsewhere in this rulebook.
20F- 15 Fuel Specifications
- SMS has instituted an approval process for all racing fuel. The intent of this rule is to help control costs, to eliminate very expensive fuel blends and fuel additives, to prevent engine damage from untried concoctions, and to ensure that the fuels used are available to all. Sunoco Race Fuel 260GTX is the only fuel permitted. The fuel may not be blended with any other fuel or additive. This fuel is available for purchase in the SMS paddock area. Several testing procedures will be utilized to ensure the fuel is pure Sunoco Race Fuel 260GTX, with no additives. All fuel samples taken must exactly match all of the manufacturer’s printed specifications or penalties may result.
- Icing or cooling of the fuel system is not permitted anywhere on SMS property.
- Fuel may be tested and certified at any event through the application of various chemical analyses as considered appropriate by SMS Officials. Fuel may be checked before, during and after racing events.
- Nothing may be placed in the fuel line except a standard fuel filter. The use of any type of fuel catalyst or other fuel-altering device is prohibited.
20F- 16 Fuel System
20F- 16.1 Fuel Cell
20F- 16.2 Fuel Cell Container
20F- 16.5.3 Fuel Shut-off
20F- 16.3 Fuel Cell / Conatiner Installation
20F- 16.4 Fuel Filler / Vent Requirements
20F- 17. 4.1 OEM Frame Roll Bars
20M -18 Roll Bars X-Y-G Frame
NOTICE – Competitors are solely and directly responsible for the safety of their race cars and racing equipment and are obligated to perform their duties (whether as a car owner driver or crew members) in a manner designed to minimize to the degree possible the risk of injury to themselves and others.
NOTE: All vertical (height) body measurements are at ride height with driver in the car, and all vertical (height) frame dimensions are at ride height.
SPECIAL STREET STOCK RULES
HANDICAPPING – Current season Street Stock feature winners will not be posted to start higher than 5th position in any feature events (EIRI). When there are “ties” in the Handicapped order, drivers will be placed according to their “wins”, the driver with more wins starting behind the driver with fewer.
YELLOW FLAG – CAUTION – Slow down as soon as possible. The pace car will pick up the leader.
Rules For Pit Road:
If you choose to come down pit road during an event to have your car inspected for damage or leaks: Bring your car to the stand on pit road. Your car will be inspected (but not serviced or repaired) for damage and leaks. If your car is OK, you will be instructed to join the field at the rear of the running order. If, in the judgement of SMS pit road officials, your car has damage or leaks that are not safe, you will be done for the event.
If you are told to come to pit road for an inspection: Bring your car to the stand on pit road. Your car will be inspected for damage and leaks. If your car is OK, you will be instructed to join the field. If, in the judgement of SMS pit road officials, your car has damage or leaks that are not safe, you will be done for the event.
Drive-through penalty: If you are assessed a drive-through penalty for an on-track incident, you must come to pit road immediately, and drive through / down pit road at 25mph, rejoining the field at the exit of pit road.
Black flagged from the event: If you are black-flagged out of the event, you must come to pit road immediately.
CONTINGENCIES– Contingency sponsors are a valuable part of the SMS program. Contingency stickers must be displayed for either product or monetary considerations. Each division will be notified as to what stickers are required to be eligible for contingency rewards. The sticker must be displayed on both sides of the car in such a manner as to be clearly visible in a photograph. Contingency stickers must be used as supplied by SMS. Alterations to the stickers are not permitted.