Late Model Rules

Building Rules

Notice: All model, engine, or equipment changes or modifications not governed by the following Shangri-La II Rules must be submitted for consideration of approval, not less than 30 days prior to the date of intended usage in competition. Equipment will not be considered as having been approved by reason of having passed through inspection unobserved.

Construction and component selection of all cars in the Late Model Division must follow guidelines set forth in the following table and as detailed in the Approved Car Bodies section.

Any rules contained in the Shangri-La II Speedway Late Model Division Rulebook must be followed regardless of inclusion or exclusion from the ABC Body Program Rules.

Late Model Demensions Chart

Late Model Demensions Diagram



1.0 Approved Car Bodies
All cars competing for season points (registered team & driver) must use Five Star, ARP, or other ABC bodies that conform to ABC and Shangri-La II measurements or teams may compete with non ABC Bodies that meet the dimensions outlined above. All bodies must be kept neat in appearance.

1.1 The following bodies are approved for competition:

  • ABC Bodies: Impala, Monte Carlo, Fusion, Camry, Grand Prix, Taurus, Charger, Avenger & Intrepid
  • Other non ABC bodies permitted with weight adjustments:
    Monte Carlo, Lumina
    Grand Prix
    Intrepid, Charger
    Thunderbird, Taurus, Fusion

1.2 General Car Body Requirements

  1. Cars must be neat appearing and have complete bodies. No altering of bodies or body style permitted without track approval. That is, all body panels installed must match the brand of car, which is indicated on the front of the car.
  2. Down force Bodies are allowed with 75 lb. (pound) weight penalty but must not be altered from Manufactures specifications except as allowed on Down force Body Dimension sheet.
  3. Outlaw ‘wedge’ style bodies are prohibited.
  4. “ABC” Five Star & ARP bodies must fit templates within 1/2” (inch) and maintain all dimensions in diagram for “ABC” Dimension Guidelines page. All car base weights are based off the utilization of the ABC body. Other bodies that are previously mentioned may be permitted with appropriate weight penalty as listed.
  5. No carbon fiber, Kevlar or composite body panels allowed.
  6. Rub rails or nerfbars are allowed outside of the perimeter of the body. Must be constructed of 3/4"(inch) box tubing and covered with Lexan type decal protectors.

1.2.1 Body Positioning and Mounting

  1. The body must remain parallel to the centerline of the tread width. Tires must remain covered by the fenders and rear quarter panels.
  2. Dimensions for body heights “A” and “I” must be no more than 16" difference in drop for Non-ABC Bodies.
  3. All body panels must connect in stock locations, without alteration.
  4. Right Side deck (A & B post to outside of body) maximum of 5" (inches), Exceeding 5" (inches) but less than 7" (inches) requires a 25 lb. (pound) weight penalty, exceeding 7” (inches) is not allowed.
  5. Left side deck (A & B post to outside of body) maximum of 3" (inches).
  6. Roof "X" dimension (a point on "A" post to opposite outer edge of rear spoiler) shall not exceed 3" (inch) difference.

1.2.2 Hood, Roof and Deck Lid

  1. The hood must have positive pull pin type fasteners with 4 pin fasteners on leading edge. Holes or scoops in hood are prohibited.
  2. Hoods or cowls must remain as purchased from manufacturer and may not be cut or altered in anyway, with the exception of a 3” (inch) x 20” (inch) opening at the center of the hood located at the base of the windshield, hood must seal to windshield and/or cowl. Hoods may be trimmed to fit nose, fender, cowl and/or windshield as required.
  3. Hoods must be held in place with hood pins. A minimum of four (4) in front and two (2) at the rear of the hood (unless hinged) are mandatory.
  4. Hoods must lie flat on fenders and must remain sealed to windshields at all times.
  5. ABC Style cowl air intake opening between the hood and the windshield must retain the original opening dimensions and may not be modified. Any body with a cowl air intake opening may not have any other openings in the hood.
  6. The rear trunk/deck lid must be pinned with or without hinge. Hood pins and/or DZUS fasteners are acceptable.
  7. The roof may have a maximum 3" (inches) drop, as measured from a point 12" (inches) back from the windshield to the rear window.
  8. The deck lid must not be more than 1/2" (inch) lower than rear quarter heights in any area.

1.2.3 Taillight Panel

  1. Tail-light panel must be closed and remain as manufactured. NO CUTTING ALLOWED

1.2.4 Ground Clearance

  1. Minimum ground clearance for the front spoiler/air dam shall be 3.5” (inches).
  2. Rocker panels must be a minimum of 3.5" (inches) from the ground and must remain perpendicular (90 degrees) to the ground and not bow out.
  3. Frame rails and/or any other part of the chassis must maintain a minimum ground clearance of 3.5” (inches).
  4. All measurements will be taken with a fully suited driver sitting in a normal position with helmet in lap.

1.2.5 Vanes, Skirts Air Dams, Vents, Ducts and Noses

  1. A maximum of 2 roof air vanes/deflectors are allowed, mounted parallel to each other with a maximum height of 1.0” per approval of tech inspector.
  2. Vent windows are permitted and may extend no more the 20” at the bottom of the window opening between the “A” post and “B” post area and may not protrude out side of the body more than 1”.
  3. Rear quarter panel windows may be used. Rear Quarter Windows may contain NACA Ducts to provide Driver Air and/or Brake Cooling.
  4. Brake vents may be installed in front nose subject to approval by Shangri-La II Tech Officials.
  5. Wear strips may be used on bottom of front nose to achieve 3.5” (inch) nose height.
  6. Dirt style front header, nose or rear bumper sections not allowed.
  7. Additional vanes, air dams, flared skirts or other added devices or sheet metal to divert or direct airflow are not allowed.

1.2.6 Windshield & Rear Window

  1. Full 1/8" (inch) lexan type windshields must be used. Windshield must have a minimum of two (2) internal aluminum or steel braces approximately 4" (inches) to 6” (inches) apart and roughly centered in windshield.
  2. Full rear windows are mandatory. Must be 1/8" (inch) lexan type, mounted securely, with at least two (2) internal aluminum or steel braces to prevent any collapsing.
  3. The rear window height at the top may not drop more than 1" (inch) from center to either side.

1.2.7 Bumpers

  1. Front and rear bumper covers must remain stock. NO CUTTING ALLOWED. Bumpers may be reinforced. Outside bumper reinforcement/bracing is prohibited.
  2. All cars must provide hooks and/or alternate method for towing, in both the front and rear and may be located under hood and/or trunk.
  3. Front bumper/nose must Display brand logo in center location. All bumpers must be made from Hollow Tubing not exceeding .095” (inch) wall thickness.

1.2.8 Spoilers

  1. Non- adjustable Rear Spoiler shall not exceed 6 1/2" (ABC bodies), for non-ABC bodies the following heights apply: 6” (inches) Thunderbird and 5” (inches) for other bodies in overall or surface height.
  2. The spoiler shall not exceed 60" (inch) width and must be attached to and centered on the rear bumper cover.
  3. Spoilers must be made from at least 1/4” (inch) clear polycarbonate or lexan and control the flow of air over one surface only.
  4. The spoiler must be slotted 1/2” (inch) in the center for all ABC Bodies to fit the ABC overall body template.
  5. Rudders, side enclosures or bracing, lips, bends or forward mounting brackets are strictly prohibited.
  6. The maximum height of the top of the spoiler to the ground for non-ABC Bodies shall be 38", ABC bodies 41 1/2”.
  7. No decals will be allowed on the spoiler at anytime.


2.0 Floor/Fire Walls

  1. Interior of car must be completely enclosed in respect to engine compartment, track surface, wheel wells, and rear (fuel cell) compartments. The area immediately beneath the driver (floor) and the vertical panels surrounding the seat area (front and left side firewalls and transmission tunnel) must be constructed of minimum 18 gauge steel (.047 inch) and be of welded construction. Other interior panels may be constructed of aluminum, minimum of 0.040 inch thickness. No air ducts through the firewall and/or floor are permitted.
  2. Panel on passenger side of car may be either flat across at transmission height, or angle up to the top of the right side door bars.

2.1 Dashboard

  1. A full width dashboard is required. Top area of windshield to vertical plane of dash must be enclosed. Gauges must be mounted on a vertical panel.


3.0 Car Weights

  1. All car weights and percentages listed are to be met when scaled with fully suited driver in normal seated position with helmet in lap and hands on the steering wheel.
  2. Maximum left side weight percentage for ALL cars will be 58% before, during and after event with NO Allowances
  3. Weights based on ABC body. of any form.
  4. Minimum overall car weight:
    • 2800 lbs: 11.0:1 Compression
    • 2825 lbs: 11.1:1 to 12.0:1 Compression
  5. The following are available options that are permitted in competition with established weight adjustments as listed below.
    • Add 50 lbs : Dry Sump
    • Add 25 lbs : 1999 - 2003 non-ABC template body
    • Add 25 lbs : 2004 - 2006 non-ABC template body
    • Add 75 lbs : Downforce body
  6. All weights will be taken using the Shangri-La II Scales. These scales will be the only Official method for determining weight.


Crate Motors with the following rules:

  1. Unaltered GM 604 Crate Motor Part #88958604 2800 lbs- 58% left side weight
  2. Unaltered Ford Crate Motors Part #M6007, D347SR or D347NST.  2800 lbs - 58% left side weight.
  3. Altered Crate Motors- ASA:
    1. GM 604 Part #88958604
    2. Ford McGunegill Part # ASA 425LM
    3. Dodge Part #ASA 75360

The following rules apply for Altered ASA Crate Motors:

  1. Weight 2850 lbs after race. NO EXCEPTIONS
  2. Left side weight 58%
  3. Chevy 1.6 Rockers
  4. Ford 1.5 Rockers
  5. Dodge 1.5 Rockers
  6. 1” tall Aluminum Carb Spacer with 4 Non-Tapered Holes
  7. Harmonic Balancer, Aluminum 6” minimum
  8. No Chip
  9. Maximum Gear Allowed 4.65  NO EXCEPTIONS
  10. 10. ASA approved Bee Hive Springs
  11. Caburetor: Holley Model 4150, 650 CFM Part # 80541-1

4.0 Engine Requirements
Only V8 engines allowed from manufactures GM, Ford, Chrysler (cast iron) are allowed for competition.

Note: The track reserves the right to inspect any engine for adherence to these rules at anytime, engines may be whistled and P&G tested at random.

4.1 Engine Displacement

  1. General Motors: 350 c.i. (cubic inch) displacement. OEM block plus a maximum of .061” (inch) overbore per cylinder.
  2. Ford Motor Company: 351 c.i. (cubic inch) displacement. OEM block plus a maximum of .061” (inch) overbore per cylinder.
  3. Chrysler Corporation: 340 c.i. or 360 c.i. (cubic inch) displacement. OEM block plus a maximum of .031” (inch) overbore per cylinder. Chrysler 355 c.i. (cubic inch) displacement engines are not eligible for competition.

4.2 Cylinder Heads

  1. Any steel head, limited to two (2) valves per cylinder.
  2.  12.0:1 Compression ratio is the absolute maximum allowed as measured by the whistler tool. In all cases, compression ratio will be calculated by any means deemed proper by Shangri-La II Speedway Tech Officials.
  3. Any attempt to alter, change, or eliminate part numbers will result in that part’s ineligibility.

4.3 Valves, Springs

  1. Valves must be identical in appearance and construction to OEM valves.
  2. Valve springs of any type may be used, springs must be made of steel.
  3. Titanium valve spring retainers and keepers are permitted.
  4. Multi-angle valve grinding is permitted with a maximum of a three (3) angle valve job is permitted.
    Valve Angle Specifications:

    • Ford Cleveland and GM heads with an 18 degree valve angle are not allowed for competition.
    • General Motors: Must be cast iron head, not exceeding maximum valve size and must be GM valve angle. Only GM valve angle approved for competition is 23 degrees. 
    • Ford Motor Company: Must be cast iron head, not exceeding maximum valve size and must be Ford valve angle. Only Ford valve angles approved for competition are 10 and 22 degrees.
    • Chrysler Corporation: Must be cast iron head, not exceeding maximum valve size and must be Chrysler valve angle. Only Chrysler valve angle approved for competition is 18 degrees.
    Maximum Valve size Specifications:
    All valve sizes are to be measured at the face of the valve.
    • General Motors: 2.020” (inches) Intake, 1.625” (inches) Exhaust
    • Ford Motor Company: 2.020” (inches) Intake, 1.600” (inches) Exhaust
    • Chrysler Corporation: 2.020” (inches) Intake, 1.625” (inches) Exhaust
  5. Port matching allowed up to 1/2” (inch) on intake port, maximum.

4.4 Rocker Arms

  1. Any type stud mounted Roller Rocker arms are allowed. No shaft rockers allowed with an exception for Chrysler Corporation manufactured engines.

4.5 Stud Girdles

  1. Stud Girdles are allowed.

4.6 Pistons, Rods, Cams, Crankshaft

  1. Steel connecting rods required, no titanium, aluminum or stainless steel connecting rods allowed.
  2. Only I - Beam and H - Beam type connecting rods are approved for competition. No hollow beam connecting rods are allowed.
  3. Any length after market rod permitted, must maintain stock stroke.
  4. Titanium crankshafts are not allowed.
  5. Minimum crankshaft weight is 46 lbs (pounds).
  6. Any flat top piston permitted. Valve relief may be cut into piston. Pistons may not exceed engine compression rule. Dodge pistons may remove minimal material from top of piston to maintain 11:0:1 compression.
  7. No dome, pop-up or dished pistons are allowed.
  8. All pistons must utilize the mandatory three (3) rings only.
  9. No part of the piston may protrude above the deck of the block.
  10. Any flat tappet camshaft permitted. Roller cams are strictly prohibited.
  11. Lifter bores may be bored, or re-bored and sleeved to accept Ford lifters. No mushroom type lifters permitted.

4.7 Oiling System

  1. Oil system may be of Wet Sump or Dry Sump type, Dry Sump oil systems are limited to a maximum of 5 Stages and are subject to a weight penalty as outlined in the Weight Section.
  2. An aqua-sump, is also allowed and must be located under the hood.
  3. Oil coolers are allowed but cannot be located near or in the driver’s compartment.

4.8 Intake Manifolds

  1. Any one piece, untouched, as cast manifold is allowed.
  2. The manifold must remain as produced by the original manufacturer and must be stamped with the part number.
  3. The manifold may not be modified, painted, polished or coated.
  4. Port matching is allowed up to ½” (inch) max. No other machining including but not limited to drilling or flow improvement work is permitted.
  5. No acid porting or etching of any kind. Violation of this rule will result in disqualification. Teams will also be stripped of all season points and maybe banned from competition at the discretion of Shangri-La II track officials.

4.9 Carburetors

  1. Carburetor is limited to one (1) unaltered stock 4412 Holley 500 cfm two (2) barrel, Must pass gauge inspection. HP Carburetor is allowed.
    Venturi Bore: 1.373” – 1.377”
    Booster Outside Diameter: .620” (+ or -) .10”
    Booster Inside Diameter: .390” (+ or -) .003”
    Throttle Bore: 1.6855” – 1.6856”
    Combined Throttle Shaft and Plate: .1868” - .2008”
  2. Choke may be removed and all holes must be permanently sealed. Choke horn may not be removed or altered.
  3. Boosters may not be altered in any manner including size, shape or height.
  4. Venturi area must not be altered in any manner.
  5. Stock butterflies must not be thinned or tapered. Idle holes may be drilled in butterflies. Screw ends may be cut even with shafts, but screw heads must remain standard.
  6. Throttle shafts must remain standard and must not be cut or thinned in any manner. Any attempt to pull outside air other than through the venture is not permitted.
  7. No alterations will be allowed including but not limited to polishing, grinding, or drilling holes in the body of the carburetor.
  8. Metering block must maintain stock configuration. After market metering blocks are not allowed. Resizing of bleeds are permitted.
  9. Carburetor must be mounted in stock configuration.
  10. Carburetor must pass all Shangri-La II Speedway gauge checks to be eligible for competition.

4.10 Carburetor Throttle Linkage

  1. All linkage must be mechanical type. No cable type. Two springs MANDATORY.
  2. A toe strap is MANDATORY.

4.11 Carburetor Spacer and Gaskets

  1. No alterations allowed to carburetor spacer.
  2. Only a 1 piece carburetor spacer, maximum 1” inch in thickness may be installed between the intake manifold and the carburetor. No spacer allowed if 1.0” (inch) is built into intake.
  3. The top (carb side) and the bottom (manifold side) must be parallel, No wedge shape allowed. Port Holes must be vertical top to bottom (90 Degrees). No beveling, tapering, grooving, flaring, or radiusing of port holes. Spacer may not be stepped or undercut.
  4. Port Holes must be same size and shape at the top and bottom and must pass through the entire spacer adapter with no additional holes or channels that will allow air to enter the engine.
  5. Only 2 paper gaskets (1 per side) with a maximum thickness of 0.075 inch will be permitted. Gaskets may be altered to match carburetor base openings.

4.12 Carburetor Jets

  1. Carburetor jets must be the same type as supplied by the carburetor manufacturer.

4.13 Carburetor Air Filter

  1. Air filter element must be a minimum of 12 inches and a maximum of 16 inches in diameter. Air shall be filtered through the element. K&N type filter elements are allowed along with K&N type filter tops.
  2. The air filter housing must be centered on the carburetor. No tubes, funnels or any other device which may control the flow of air is permitted between the air filter housing and the carburetor.
  3. Air cleaners cannot be removed during practice or competition.

4.14 Air Intake

  1. No cowl air induction is permitted. Absolutely no air ducts or baffles permitted on or leading to the air cleaner or element.
  2. An air box opening 3 inches by 20 inches may be cut in the hood at the base of the windshield to allow fresh air to the air cleaner and carburetor.


5.0 Ignition

  1. All ignition systems must be acceptable to Shangri-La II Tech Officials. MSD Ignition Boxes are subject to testing by the track, a track ignition box will be supplied to the competitor while their box is being tested.
  2. Any MSD Analog 6 Series Ignition amplifier boxes (6T, 6AL, 6ALN or 6 Series HVC) and RPM limiters are allowed, but must not contain programmable, computerized, or memory circuits.
  3. Ignition boxes may not be altered in any way. Any Ignition box that is found to be altered will be confiscated by the Speedway. Traction Control of any type is strictly prohibited.
  4. No magnetos or computerized systems are permitted.
  5. No crank trigger ignition systems permitted.
  6. Any distributor may be used, dual pickup distributors are allowed.
  7. The distributor must mount in the stock location and maintain the same firing order as a factory produced engine for the make and model car being used.
  8. No adjustable timing controls permitted.
  9. The entire ignition system must be mounted in the dashboard area on the passenger side of the car and remain out of reach of the driver while in the sitting position. All wiring to and from the Ignition box(s) must be visible and accessible for inspection purposes.
  10. Positive wire from ignition box to distributor unspliced, continuous wire with no insulation breaks or any other introduction point for traction control devices, any plugs must be accessible for inspection by Shangri-La II Tech Officials.
  11. Ignition system must not contain any open wire or terminals. Unused ignition amplifier box wires must be cut flush to the box. Unused rev limiting chip sockets must be permanently sealed shut.

5.1 Spark Plugs

  1. Any make or brand of spark plugs may be used.

5.2 Alternator

  1. The alternator system when used must be working within specifications.

5.3 Starter

  1. The self starter must be in working order. Gear reduction starters are acceptable. All cars must be capable of starting under their own power.
  2. After a race is underway, cars may be started by hand pushing in the pit area only, but under no circumstances is any car permitted to be pushed onto the race track from pit area.

5.4 Battery

  1. The battery may not be located within the driver’s compartment.
  2. Battery must be isolated within the fuel cell area of the car and securely mounted and covered by a non-conductive cover.
    Dry Cell batteries are exempt from cover.

5.5 Electrical Switch Locations

  1. All electrical switches must be located within the driver’s reach. A labeled on/off master switch must be located within reach of the driver’s side window opening and effectively kill power from the battery to the car’s ignition system.

5.6 Accessories

  1. Cars will not be permitted to carry on board computers, micro-controllers, processors, recording devices, electronic memory chips or digital readout gauges during competition. Radios must be of two-way voice communication type only, independent of the car’s electrical system.

Fuel System

6.0 Fuel Cell

  1. Maximum size is 22 gallons (U.S.).
  2. Fuel cell must have a minimum ground clearance height of 7.5 (inches) from the track.
  3. Must have flapper/ball valve assembly in cell to prevent spillage when upset.
  4. Must be enclosed in a 20 gauge metal canister and installed in a safe manner.
  5. Must have a check valve in vent tube to prevent spillage. Vent line must not be excessive in length.

6.1 Fuel Pumps

  1. Mechanical fuel pumps only, no electric fuel pumps allowed. Only one fuel line between fuel cell and fuel pump is allowed.

Cooling System

7.0 Radiator

  1. Must have radiator contained under the hood of the car with overflow tank. Overflow must blow on right lower quarter of windshield.

7.1 Liquids

  1. Absolutely no anti-freeze liquid allowed, water only.
  2. Products such as Liquid Cool and Water Wetter are allowed.

7.2 Water Pump

  1. Must have OEM type water pump only.

Drive Train and Running Gear

8.0 Drive Train

  1. No carbon fiber or titanium products allowed without Speedway approval.

8.1 Engine Location

  1. Engine/drive line must be centered in frame or on center of front wheels +0.50” (1/2 inch).
  2. Engine crankshaft center height must be a minimum of 10" measured from the centerline of the crankshaft/harmonic balancer to the ground.
  3. Engines manufactured by General Motors must be mounted so the location of the forward most spark plug socket center does not exceed 3.5" as determined by a line across the center of the upper ball joints. Engines manufactured by Ford Motor Company or Chrysler Corporation must be mounted so the location of the forward most spark plug socket center does not exceed 5.5" as determined by a line across the center of the upper ball joints.
  4. Engine must be mounted in a normal upright position, whereby the cylinder vertical centerline of a 90degree engine shall be a 45-degree angle to a vertical line projected from the ground plane.

8.2 Clutches

  1. External Multi-disc clutch designed for racing, minimum of a 5.5” (inch) clutch allowed.
  2. No internal or dog-type clutches are allowed.
  3. Carbon fiber, Titanium and Ceramic clutch parts of any kind are not allowed this includes Carbon Fiber clutch discs.

8.3 Flywheel

  1. Must have flywheel with starter ring. No carbon fiber or titanium drive train parts or fasteners permitted. Flywheel must be bolted to and turn positive with the crankshaft.

8.4 Bell Housing

  1. Any aluminum, magnesium or steel bell housing allowed. Bell housings utilizing reverse mount starters are allowed.
  2. Bell housing must contain a 2.5” (inch) inspection hole on side or bottom.

8.5 Transmission

  1. Transmissions must be of production type three, four, or five speed cases.
  2. Not to exceed 4 forward gears. Must have at least two (2) forward gears and one (1) reverse gear in working order.
  3. Fourth or high gear ratio must be 1 to 1.
  4. Manual Shifting linkage only, no assisted shifting (e.g. spring, electric, hydraulic).
  5. No “in-out” type transmissions including but not limited to BERT and Brinn are permitted.
  6. No automatic or semi-automatic transmissions permitted.
  7. All transmissions must be approved by Shangri-La II Officials.

8.6 Drive Shaft

  1. Drive shafts and universals must be similar in design to standard production type. Only a 1 piece steel or aluminum drive shaft permitted, no carbon fiber allowed.
  2. It is mandatory that two (2) 360 degree solid steel brackets, no less than 1.5” (inches) wide and 1/4 inch thick, be placed around the drive shaft located 6.0” (inches) from the front and 6.0” (inches) from the rear and fasten to the cross member or chassis of the car.
  3. All drive shafts must be painted white.

8.7 Rear Axle

  1. Any rear end center section with magnetic spur gears will be permitted but must not use any electronic devices.
  2. Full floating rear axles are compulsory.
  3. Must utilize a solid spool, no lockers or limited slip differentials, either locked or unlocked of any kind (e.g. Detroit Locker, Gold Track, etc…) are allowed.
  4. Cambered rear axle housings, tubes, or snouts or any combination thereof any are not permitted.
  5. No independent type or open tube rear ends are allowed.
  6. Rear Quick Change center section may be constructed of aluminum or magnesium. All other parts and components must be constructed of either steel or aluminum, and as specified. Titanium, magnesium and/or any other special alloy or ceramic is not permitted.
  7. Front Mount Quick Change rear ends are allowed.
  8. Differential oil coolers are permitted.
  9. Steel, aluminum or rubberized drive hubs may be used.
  10. Final gear ratio : nothing over a 500

8.8 Track Bar

  1. Only one (1) Track bar (Pan-Hard or J-Bar) is allowed. Adjusting devices will not be permitted on the interior of the car within the drivers reach.
  2. Any car with an adjustable track bar (Pan-Hard or J-Bar) device inside the interior of the car must have the extension device in a vertical position and mounted as straight up as practical.

8.9 Wheels

  1. Only 15-inch diameter 5 lug steel wheels with a 10-inch rim width and a reinforced center are permitted.
  2. Solid heavy-duty steel lug bolts and nuts must be used, hollow studs are not allowed.
  3. Wheel Spacers, if used, must be made of steel or aluminum and a minimum 6.75” (6 3/4 inches) in diameter. Shims are not permitted when mounting wheel studs to hubs.
  4. Bleeder valves are not permitted.

8.10 Headers, Mufflers and Exhaust

  1. Any steel header is allowed, no 180 degree headers.
  2. All cars must have mufflers in "as produced condition" and meet sound level specifications.
  3. Cars not adhering to this rule or excessively loud cars may not be allowed to compete.
  4. Exhaust must extend behind driver. The exhaust must exit under the car. A minimum of 6” (six inches) is required between door panel and location of exhaust dump point. Must be turned down.
  5. Maximum allowable noise decibel to be 95db (decibels).

Chassis Construction

9.0 Wheelbase, Tread Width, Frame Height

  1. Minimum wheelbase is 102" (inches) on either side. The left side wheelbase must be +/- 1" (inch) of right side. Maximum wheelbase is 108" (inches).
  2. Maximum tread width front and rear is 66" (inches) measurements will be taken from center of tires at spindle height, tolerance of 1” (inch) max is allowed.
  3. Absolute minimum height of frame and cross members is 3.5" (inches) from ground before, during, & after each race event with fully suited driver in the car in the normal sitting position. There is Zero (0) tolerance on frame height. Rear spoiler height maximum must be maintained before, during, & after each race event.

9.1 Center Section Components

  1. Main frame rail structure of chassis, defined as the primary structure to which roll cage members, major suspension components, engine, etc., mount to (center section) must be constructed of a mild steel box tubing with a minimum of size of 2.0” (inches) x 3.0” (inches) x .120” (inches) steel box.
  2. Main frame rail members shall be constructed so that the side rails are located within the normal tread width of the car. Right side main frame rail may be of perimeter or straight rail design.
  3. A perimeter chassis is defined as having symmetrical left & right frame rails (max 1” (inch) tolerance).
  4. Frame rails must measure a minimum of 52” (inches) and a maximum of 60” (inches) from outside to outside and must be a minimum of 44” (inches) in length.
  5. The left main frame rail on a straight rail chassis must measure 10” (inches) minimum from the left front frame rail.
  6. When using an under-slung front snout on a straight rail chassis, the right main frame rail must be outside of the right front frame rail. They must not be in a straight line.

9.2 Front and Rear Sections

  1. Front and Rear Clips must be constructed of mild steel box tubing with a minimum of size of 2.0” (inches) x 3.0” (inches) x .083” (inches) steel box.
  2. Rear frame section must extend beyond the rear edge of the fuel cell. The rear frame section maybe be 2.0” (inches) x 2.0” (inches) from the rear axle rearward.
  3. Rear frame section may be fabricated above or below the rear axle.
  4. Front and rear frame sections centerline must be located within 1” (inch) of the centerline of the main frame section. Front clip may or may not be passenger car type.
  5. Rear frame section must measure a minimum of 38” (inches) outside to outside.

9.3 Right Side Door Bar

  1. Off-set chassis right side door bars commonly called The Outrigger or The Kick-Up Bar, must be constructed of a minimum 1.250” (inches) x .065” (inch) wall round or square steel stock. All supporting Sub-structure must be constructed of 1” (inch) x .063” (inch) wall round or square steel stock. No material substitutions permitted.

9.4 Suspension Components

  1. Front and rear suspensions may be coil spring or coil over spring type.
  2. Rear trailing arms may be of any unequal length and may use a spring or shock assembly.
  3. The third link may be of any length or type.
  4. Rack and pinion steering is allowed.

9.5 Brakes

  1. Hydraulically activated, four wheel disc brakes are mandatory, brakes must be in a good operating condition on all four wheels at all times.
  2. Any aftermarket caliper may be used.
  3. Brake bias adjusting device in driver’s compartment is allowed.
  4. Master cylinders and reservoirs should be mounted in the engine compartment.
  5. When master cylinders are mounted in driver’s compartment they must be covered.
  6.  Electric brake actuators are not permitted.
  7. No carbon fiber, titanium or ceramic brake components are allowed.
  8. Any steel, non-coated rotor allowed, Minimum rotor size outside diameter/thickness:
    • Front: 11” (inch) x 1 1/4” (inch)
    • Rear: 10” (inch) x .810” (inch)
  9. A maximum of two hoses per wheel may be used for brake cooling.
  10. An approved Anti-Lock Braking (Sierra or DEI type) system and/or brake fluid re-circulating system is allowed.

9.6 Springs

  1. Type of springs including height and wire diameter is optional.
  2. Spring rubbers are permitted and must be removed manually. No removal devices may extend out side the body of the car or be accessible in the driver’s compartment.

9.7 Shocks

  1. A maximum of 1 shock absorber per wheel is permitted.
  2. No experimental shocks.
  3. Type and location of shock absorbers is optional. External Shock Reservoirs are permitted.
  4. Quick Disconnect shocks not permitted, shocks must be securely bolted.
  5. No in-car, electronic, or remote (cockpit) adjustable shocks are permitted.
  6. External Schrader valves to pressurize shocks with nitrogen are permitted.

9.8 Sway Bars

  1. Any type sway bar is allowed.

9.9 A-Frames

  1. Independent front suspension is mandatory with articulating upper and lower control arms.
  2. Lower A-frames may be stock appearing or strut arm type.
  3. Upper and lower A-frames may be unequal lengths.
  4. Ball joint type is optional. Mono balls are allowed.

9.10 Spindles

  1. Steel spindles only. Floater or safety hubs are required.