Irwindale Race Trucks

 

2018-2020 IRWINDALE SPEEDWAY IRWINDALE RACE TRUCKS RULES

ALL RACE EQUIPMENT IS SUBJECT TO INSPECTION BY IRWINDALE SPEEDWAY, AT ANY TIME AND IN ANY MANNER. ALL EQUIPMENT IS SUBJECT TO THE APPROVAL OF IRWINDALE SPEEDWAY OFFICIALS. ANY MOFIFICATIONS NOT COVERED IN THESE RULES WILL NOT BE ALLOWED UNLESS APPROVED BY IRWINDALE SPEEDWAY IN WRITING. MODIFICATIONS TO ANY SPEC PART(S) IS NOT PERMITTED. NO EQUIPMENT WILL BE CONSIDERED AS HAVING BEEN APPROVED BY REASON OF HAVING PASSED THROUGH INSPECTION UNDETECTED AT ANY TIME OR ANY NUMBER OF TIMES.

  1. COMPETING MODELS
  2. Open to stock appearing trucks provided they comply with specifications as outlined
  3. for this
  4. Competing models as selected by Irwindale Speedway: the following trucks are the only eligible models approved for competition:

Chevy S-10

Ford Ranger

Dodge Dakota

Toyota Tacoma.

 

  1. GENERAL TRUCK AND BODY REQUIREMENTS
  2. General Truck
  • Spec Truck is the standard for Irwindale Race Trucks at Irwindale Speedway. Trucks must be neat appearing. All panels must fit properly and be free of sharp edges.
  • Bodies must be standard as produced by manufacturer.
    1. Spec part required: cab-half (roof/door half), STI part number:
    2. Spec part required: bedside, STI part number:
    3. Spec part required: tail, STI part number:
  • All body mounting will be stock as
  • Truck bodies will be required to fit an Irwindale Speedway approved overall body
  • Body mounting and body location must remain in stock
  • Flat or slab-sided or deformed bodies not
  • Carbon Fiber or Kevlar body parts not
  1. Floorboards
  • All holes in floor must be
  • Floorboard must be a minimum of 16-gauge magnetic
  • Floorboard and tunnel must be welded in place and show good
  1. Interiors
  • Interior must be completely
  • Interior panels must be trimmed neatly around roll cage and sealed for fire
  • Interiors panels must be painted and must fit properly and free of sharp
  • Interior panels except crush panels must be fabricated of 24-gauge magnetic steel
  1. Overall Truck Weight:
  • Minimum weight all trucks, 2,700 pounds, including driver before the
  • Maximum left side weight 0% at all times including driver.
  • Maximum rear weight all trucks, 0% including driver.
  1. Added Truck Weight:
  • Added weight must be in block form of no less than ten (10)
  • All added weight MUST be painted white with the truck number on it.
  • All added weight must be securely bolted in place with a minimum ½-inch
  • Weight may not be located inside the driver’s
  • Any lead mounted behind the rear axle must be in front of the fuel
  • Weight shifting devices shall not be

 

 

 

  1. DETAILED TRUCK BODY REQUIREMENTS
  2. Front Air Dam and Nose
  • Spec part required: nose, STI part number:
  • Holes for ducting air allowed in the front air dam for air inlet
  • All support brackets and bumpers must be mounted behind
  • Front nerf bars, or external reinforcing bars are not
  • The nose may not be altered by trimming to enhance aerodynamic performance.
  • Nose widths and dimensions must remain
  1. Rear Spoilers
  • All trucks must use a spoiler that is 6-1/4 inches in height and 56 inches in
  • Spoiler must be attached and centered to the rear of the Spoiler cannot be curved.
  • Rudders or braces in front or behind of the spoiler are not
  • Rear spoiler must maintain a 65 degree
  1. Windshields
  • A clear Lexan polycarbonate windshield with a minimum 1/8-inch thickness must be used.
  • A minimum of one metal brace support must be mounted in the center
  1. Rear Window
  • The rear window must be used and must be made of clear minimum 1/8-inch thick Lexan polycarbonate.
  1. Side Windows, Quarter Windows, Air Deflectors and Net
  • Side Window and Quarter Windows
  1. Side window openings must retain original
  2. Door windows may not be
  • Deflector and A-post
  1. A-post deflector must be of clear Lexan polycarbonate and may not protrude outward.
  2. The deflector must not be longer than twelve (12) inches in length.
  • Window Net
  1. Mandatory left side window net Net must be a rib type with one (1) inch wide nylon material. Window net lower mount must be a solid steel rod ½” diameter on the bottom with rod mounts welded to roll cage. Window net upper mount must be solid steel must be ½” inch diameter rod (or 1” x 1/8” flat bar) with mounts welded to roll cage. The window net must fit tight and secured with a lever-type quick release latch at top.
  2. Window net must have a manufacture’s date tag within 5
  • Rear View Mirror
  1. All trucks must have only one (1) rear view Spot mirror permitted and must not extend outside of the body.
  2. Doors
  • Doors must retain stock for contours and
  1. Fenders
  • All fenders and side of bed must be mounted as per specifications, and not be concaved or deformed behind
  • Fenders may only be trimmed at wheel opening for tire clearance
  1. Quarter and Rocker Panels
  • Quarter panels and side of bed must be mounted as per
  • Quarter panels and side of bed behind tires cannot be pulled in or
  1. Grill
  • Openings in the grill may be cut in the stock opening portion only to allow airflow to the engine.
  1. Hood
  • Spec part required: hood, STI part number:
  • Hood must maintain original configuration when fitted to vehicle, hood cannot be deformed to enhance airflow to the engine
  1. Roof
  • All roofs must be stock configuration and mount in stock location with no
  1. Rear (Bed) Deck Lids
  • Rear deck lids and bed covers must remain flat to top of rear quarter panels with no spacing, shimming or
  • Bed cover may be
  1. Bumpers and Rear Filler Panel
  • Bumper supports or reinforcements may only be added using stock attachment points and may not extend outside the
  1. Identification and Marking
  • Numbers must be at least 20” high and on both sides of the truck in the center of the
  • A number 22” in height must be painted on the roof, reading from the passenger
  • Gold or silver foil numbers are not
  • All race truck numbers will be issued through the Absolutely NO “x”s or duplicate numbers allowed at any time.
  • Block type numbers six inches in height must be attached to the right front headlight area, and the right rear taillight

 

  1. GENERAL ENGINE REQUIREMENTS
  2. Only engines of a type approved by Irwindale Speedway are
  3. Approved Engine Type: Spec Motor, Vortec, GM part number: 12486041 or GM part number:
  4. All competition-approved motors must be purchased through approved spec motor
    • Engine must be purchased complete and sealed from approved spec motor
    • Engine is sealed on intake manifold, timing cover, and oil Seals may not be broken or removed except by approved spec motor supplier or Irwindale Speedway Tech Official.
    • Engine may not be modified in any way and must remain intact as originally sold by the approved spec motor
    • Only approved spec motor suppliers are authorized to perform repairs to any engine requiring the breaking or removing of engine
    • Only approved spec motor suppliers are authorized to reassemble and reseal any spec motor, including but not limited to:
  5. Disassembled during post-race
  6. Any engine having a broken seal(s). Any engine with a broken seal is subject to inspection of internal components as deemed necessary by approved spec motor suppliers.
  7. The following are approved spec motor suppliers:
  • The Loe Pit Stop – 19425 Santa Fe Way, Shafter, CA 93263 – 661-829-2140
  • GM Performance – any authorized GM dealer
  • JMS Racing Engines, 5450 Peck Rd., El Monte, CA 91732 – 626-579-4567
  • Van Dyne Engineering, 17696 Metzler Lane, Huntington Beach, CA 92647 – 714-847-4417
  1. All engines must remain

 

  1. DETAILED ENGINE REQUIREMENTS
  2. Engine Location
  • The centerline of crankshaft must remain centered in
  1. Engine Mounts
  • All engine mounts must be securely
  1. Engine Displacement
  • A P&G cubic inch measurement tool may be used to evaluate cubic inches without tear down.
  1. Engine Compression Ratio
  • The maximum compression ratio is 1 to 1 on all engines.
  • Compression ratio will be calculated by Irwindale Speedway Tech
  1. Piston/Rods
    • Stock OEM pistons only, GM part number
    • Stock OEM rods only, GM part number
  1. Oil Pans and Coolers
  • Spec part required GM part number 1286041 for GM part number 8895602 as
  1. Cylinder Heads
  • Valve springs: seat pressure cannot exceed 85
  • Valve springs must be GM part number:
  1. Crankshaft and Harmonic Balancer:
  • Spec part required, harmonic balancer, one of the following mandatory:
  1. GM part number:
  2. GM part number: 12555879, 8
  3. GM part number: 12551537, 6-3/4
  4. Camshaft, Valve Lifters, and Rocker Arms
  • Rocker arms must be GM part number: 10089648, 5 to 1 ratio.
  • Rocker shaft poly or nylon lock nuts
  1. Intake Manifold
  • Spec part required: for GM part number 1286041 intake manifold, Performer Vortec, Edelbrock part number: for GM part number 8895602 as supplied.
  • The manifold must remain as produced by original
  • Modifying, drilling or flow improvement work of any kind is not
  1. Carburetor
    • Holley List 4412, two-barrel, 2300 Model, 500 CFM carburetor is the only approved
    • Approval of carburetor shall be conducted on a race-to-race
    • Any carburetor modification not specifically covered in the rules will NOT be
    • Choke linkage actuator rods may be
    • Choke horn must not be Choke horn butterfly plate must be removed.
    • Boosters height must remain
    • Two (2) throttle return springs
    • A carburetor adapter meeting the following must be used:
  2. A single aluminum adaptor with (2) square cut holes.
  3. All trucks must have one carburetor mounting stud or bolt, and one adjacent adapter mounting stud or bolt drilled to accept a wire type
  4. Air Intake (air filter)
    • Spec part required: air cleaner assembly, K & N part number: 60-1150.
    • All air must be filtered through the filter element, K&N part number E-1200.
    • Only round uncoated metal air filter housings
    • Controlled vacuum leaks are not
    • Ducts or hoses to the air cleaner or element are not

 

  1. ENGINE/TRUCK ELECTRICAL SYSTEM
  2. Ignition System
  • Spec part required: distributor, GM part number:
  • Coil, module and magnetic pick-up replacements permitted that do not exceed stock spec part performance
  1. Alternator
  • Driveline mounted or engine mounted alternator
  1. Starter
  • The self-starter must be in working order and mounted in stock
  • All trucks must start under their own
  • After racing is underway, trucks may be restarted by means of
  1. Battery
  • The approved battery must be located in a steel battery
  • Twelve-volt system battery
  1. Electrical Switches and Locations
  • All switches must be located within easy reach of the
  • A labeled (minimum ½ inch letters) on/off master switch is required and must be located in the driver’s compartment so that it is accessible from both sides of the
  • The on/off master switch must be connected to the battery cable in such a manner that would cut off all electrical power to the
  1. Accessories
  • On-board computers, traction control devices, recording devices, telemetry devices, automatic lap scoring/timing devices (other than those issued by Irwindale Speedway), or digital readout gauges will not be
  • Any driver and/or truck found with an electronic traction control device will be suspended for 1 year and be fined a minimum of $500.00, and result in loss of all championship

 

  1. Radios
  • Two-way radio communication between driver and crew is
  • The Official Irwindale Speedway radio vendor must clear your radio
  • During the race event, each competitor must have a spotter in the designated location and that spotter must monitor Irwindale Speedway race
  • During practice, each competitor must have a
  • One truck radio, one wiring harness, and one antenna

 

  1. ENGINE COOLING SYSTEM
  1. General Cooling System
    • Engine cooling system must be acceptable to Irwindale Speedway Tech
    • No anti-freeze in cooling.
  1. Water Pump
  • Approved OEM stock type water pumps
  • Water pump pulley may be changed and must be V-belt type
  1. Fan
  • Electric fan(s) are
  1. Radiator:
  • Radiator assembly radiator core dimensions: 34-1/2 by 24-1/4 by 1-7/8 inches, plus or minus 1/8
  1. Overflow:
    • An approved overflow system is
    • The reservoir outlet hose must exit outside the

 

  1. ENGINE LUBRICATION
  2. Oil:
  • Any oil may be
  1. Oil Filter:
  • Any single production type oil filter in stock location may be

 

  1. ENGINE EXHAUST SYSTEM
  2. Exhaust Manifold:
  • Spec part required: headers STI part number:
  1. Exhaust Pipes:
  • Pipes must be securely fastened to Pipes must be securely attached to the frame or chassis with bolts in a minimum of two separate locations.
  • Exhaust pipes must extend past driver and either turn down or to outside of
  • Tri-Y header not
  1. Heat Shields:
  • A heat resistant floor mat, that is properly secured, may be used in the driver’s
  1. Mufflers:
  • Spec part required: muffler, STI part number:
  • Muffler must be capable of maintaining a maximum of 90 DECIBALS AT 100
  • Muffler must be in place at all

 

  1. DRIVE TRAIN
  2. Transmission:
  • Spec part required: GM Power Glide automatic Transmission assembly must remain unmodified from the spec transmission requirements.
  • Transmission must not weight less than 100 pounds with
  • Transmission shifter/selector boot seal required STI part number: (4) Internal parts may not be lightened or modified.
  • The approved flex plate is GM part number 14088765 or equivalent aftermarket with the same size, shape, and
  • Permitted transmission changes
  1. Output bushings may be replaced with bearings to accommodate alternator belt Any transmission hardened input shaft.
  2. Band material and clutch plate material may be any
  3. Gear ratio must be 1:82 or 1:76.
  4. Pan extended for right side pick-up.
  5. Drive Shaft:
    • Spec part required: drive shaft, STI part number: 0548, three (3) inches in minimum diameter, minimum thickness of 060 inch.
    • Only one-piece magnetic steel drive shaft
    • It is mandatory that two 1/8 inch x 1-1/2 inch steel drive shaft hoops front and rear be installed in a safe manner and installed so as to prevent the drive shaft from becoming dislodged and falling onto the race
    • All drive shafts must be painted
    • All drive shafts must have truck number painted on (7) No aluminum drive shafts.
  1. Rear Axle:
  • Spec part required: rear axle housing including all mounting brackets and suspension mounting brackets, STI part number:
  • The rear axle housing must remain stock to original specs. .188 wall GN housing. All mounting and suspension mounting brackets must remain in spec
  • Axle housing must be made of magnetic
  • Gear assembly must remain unmodified from the spec gear requirements.
  • Rear end gear ratio must be 456 or 457, approved gears are as follows:
  1. Richmond part numbers: 69-0185-1.
  2. Motive Gear part numbers: F9-456, F890-457.
  • Polishing or coating of ring and pinion is
  • Gears must remain as produced, no lightening or back cutting
  • No “AX” cut gears or factory outside machine gear
  • Steel mini spools
  • Rear axle assembly must not weight less than 230 The rear axle assembly for determining minimum weight includes: oil, hubs, axles, third member, housing, and brake components.
  • Spec parts required: axles, STI part number: 0566, 26-3/4 inch left axle; and STI part number: 0563, 31 inch right Minimum OD 1.200” solid
  • Rear end pinion must remain centered between left and right
  • Solid magnetic steel axles
  • Third member including bearing retainer and yoke must be made of magnetic
  • Quick change rear end not
  • No cambered rear
  • No tapered or crowned rear axles.
  • Rear axle coolers not
  • Drive plates must be made magnetic steel.
  1. Wheels and Lug Bolts:
  • Spec part required: Wheels: Circle Wheel P/N 5 or Diamond Wheel 15080-18-35-225-6-00 for black, Circle Wheel P/N 04580550225.5 or Diamond Wheel 15080-18-35-225-2-00 for chrome.
  • Diamond Racing Wheel has bought Circle Racing wheel. Wheels must be 15-inch steel wheels with a maximum 8-inch rim width, minimum weight 25# and only 2.25” back space.
  • Solid heavy-duty 5/8-inch steel studs and 1” hex lug nuts must be used on all four
  • The use of bleeder valves is not One valve stem per wheel.
  • Wheel studs must protrude past lug
  • All tire/wheel balance weights must be installed facing towards the inside of (6)  Wheel spacers are not permitted.
  1. Tires
  • Tires must be purchased from Irwindale Speedway.
  • Approved tire is Hoosier 970 – 8”. No Star tires.
  • Tires will be scanned and logged to each truck.
  • Tires that have been altered by any means will not be permit No tire shaving.

Tire Rule:

  1. At a competitors first event of the season he/she will be may purchase five (5) new tir
  2. At each race after the competitors first race he/she will be allowed one (1) recorded tire.
  3. You must race the tire the night you log/scan it in for competition.
  4. You must qualify and start the race on logged/scanned tires.
  5. You must practice on 970 tires.
  6. Flats or damaged tire in an accident must be presented to Track Officials before the end of the night to be evaluated.
  7. Irwindale Speedway reserves the right to impound tires for storage between ev

 

  1. FRAME REQUIRMENTS
    • Spec part required: frame/full tubular chassis, STI part number:
    • Spec part required: front clip, STI part number: (c) Spec part required: rear clip, STI part number: 0307.
    • Frame/chassis must remain stock as produced by Spec Truck Inc. Frame/chassis repairs must maintain original

 

  1. SUSPENSION
  2. General Suspension
  • No alteration of any type will be allowed to any suspension components except for the modifications listed
  • Damaged suspension parts must be repaired as close as possible to original
  1. Front Suspension
  • Camber and caster may be changed by any conventional
  1. Front Coil Over Springs
    • Front coil over style shocks/springs shall be allowed on the front of the
    • Single coil over spring
  1. Rear Suspensions
  • Rear lower trailing arms must be
  1. Rear Coil Over Springs
  • The rear springs must mount on the rear axle in equal distance left to
  • Rear coil over style shocks/springs shall be allowed in the
  • Single coil over spring
  1. Sway Bars (Anti-Roll Bar)
  • Chain link sway bars not
  • Rear sway bars are not
  • Front spec sway bar required, GM part number: 015677614, one (1) inch outside
  • Front sway bar adjusting device must be approved STI part, and must attach to lower control arm at the lower shock
  1. Track bar
  • Spec part required: pan-hard bar, STI part number:
  • Pan hard bar spec clamp part number:
  • Remote panhard bar adjuster STI part number
  1. Shock Absorbers
  • Spec part required: the following shocks are permitted only:
    1. AFCO, Series
    2. QA1-Series
    3. Carrera, Series
    4. Advanced Racing Suspensions, 2000 Series, Non-Adjustable.
  • Only one shock per wheel is
  • Shocks absorbers and components must be used as supplied by the manufacturer and all components must be used in only their respective manufacturer’s shock Modification or changes to the shock absorber and internal components will not be permitted.
  • All downward chassis movement while the race car is in competition must be limited only by the normal increasing stiffness of the springs or the bottoming of the chassis against the race track, whichever occurs
  • NO BUMP STOPS.
  1. A-Frames
    • Upper and lower A-arms must be made of magnetic steel and remain stock
    • A-arms cross-shafts must be magnetic steel or
    • Upper A-arms may be shimmed up to 1 inch off mounting
    • Upper ball joints must be Afco part number: 20032-1 and remain
    • Upper A-arms must be the spec A-arms and must remain
      1. L/F Upper A- Arms must be 9” Afco part number:
      2. R/F Upper A- Arms must be 8” Afco part number:
    • Lower A-arms must be the spec A-arms and must remain
      1. Spec part required: lower control arm STI part number
    • Lower A-arm adjusting rods must be
  1. Spindles, Wheel Bearings and Hubs:
    • Spec parts required: right front spindle, GM part number: 18021053; left front spindle, GM part number:
    • Spec parts required: rear axle hub, AFCO part number:
    • Spindles must remain stock OEM.
  1. Tread Width Requirements:
  • Front tread width shall not exceed a maximum of 70 inches measured from outside of rim at bead of tire to outside of rim at bead of
  • Rear tread width shall not exceed a maximum of 69 inches measured from outside of rim at bead of tire to outside of rim at bead of
  1. Wheelbase Requirements:
  • Wheelbase minimum is 108 inches on one side, and plus or minus 1/2 inch on opposite
  1. Ground Clearance Requirements:
  • No part of the chassis shall be lower than minimum 4 inches at any time, measured without the
  • Side skirts and body must maintain a minimum 4 inches height at all times, measured without the driver.
  • Approved front nose and lower air dam must maintain a minimum ground clearance of 4 inches, measured without the
  1. Truck Height Adjusting Devices:
  • No adjustable shock mounts.
  • Optional remote panhard bar adjuster STI part number: 1401, is

 

  1. STEERING
  • Steering box must be No Delphi boxes.
  • Power steering pump must remain OEM type.
  • Pitman arm spec part required STI part number
  • Center top of steering wheel must be padded with 2 inches of resilient
  • An approved all metal quick-release steering wheel coupler must be
  • All steering shafts are required to have a collapsible steering section, part number:
  • Steering shafts are required to have two (2) unsupported universal
  • No Delphi style steering boxes

 

  1. BRAKES AND COMPONENTS AND BRAKE COOLING
  2. Brake Components:
  • Spec parts required: left front brake caliper, GM part number: 18015427; and right front brake caliper, GM part number:
  • Spec parts required: left rear brake caliper, ARI part number: 10-4125; and right rear brake caliper, ARI part number: 10-4126.
  • Spec parts required: front brake rotors, GM part number:
  • Brakes must be in a good operating condition on all four wheels at all
  • Only hanging type brake pedal/linkage assembly is
  • Any brake master cylinder may be
  • Any master cylinder located inside the driver’s compartment must be
  • One adjustable proportioning brake valve may be
  • No carbon fiber
  • No titanium
  1. Brake Cooling
    • Brake cooling ducts only permitted below the front bumper line.
  1. FUEL
  2. All trucks must compete with fuel purchased from Irwindale Speedway.
  3. All fuel must be Sunoco 110 octane Standard fuel and run as
  4. No cooling or icing of any fuel or fuel
  5. No fuel additives.

 

  1. FUEL SYSTEM
  2. Fuel Cell
  • Spec part required: spec fuel cell, Fuel Safe part number: SM115, with 15-gallon
  1. Fuel Cell Container:
  • The fuel cell must be completely enclosed in a steel container (box), minimum 22-gauge.
  1. Fuel Cell and Fuel Container Installation
  • Fuel cell must maintain a minimum height of 9-1/2 inches, measured from ground level, without the
  • A steel framework, welded to frame rails, must be used to mount fuel This framework must be fabricated from a minimum of 1-inch x 1-inch x .065-inch square tubing.
  • Fuel cells must be securely mounted behind the rear axle, and between the frame
  • A fuel cell protector bar made from a minimum of 1-½ inch x .090 inch steel tubing is
  • The length must be greater than the width of the fuel cell and must extend lower than the fuel cell.
  1. Fuel Vent Requirements
  • Fuel cell vent hose minimum 5/8 inch, maximum one (1) inch, and must extend to outside at left rear taillight
  1. Fuel Lines
  • Only one (1) fuel line from fuel cell to fuel pump is Maximum diameter 5/8 inch ID.
  • If a fuel line runs in the driver’s compartment, it must be enclosed in a steel
  1. Fuel Pump
  • Spec part required: fuel pump, GM part number: Stock equivalent, OEM type mechanically driven, fuel pump replacement permitted.
  • No electric fuel pumps
  • Fuel pump must be mounted on engine in the stock
  1. Fuel Filter
  • Glass fuel filters not
  1.   Fuel Filler Cans
  • Fuel must be stored in approved containers.

 

  1. PERSONAL SAFETY EQUIPMENT AND ROLL BARS
  2. General Safety
  • Each competitor is responsible for the effectiveness of personal safety equipment. Each competitor is expected to educate themselves fully with respect to the availability and effectiveness of personal safety equipment. It is the sole responsibility of the driver to ensure that he/she maintains, wears and properly uses protective clothing and safety equipment.
  1. Protective Clothing
    • It is recommended that at all times, the driver wears a driving suit and gloves of fire resistant material that effectively covers the
    • It is recommended that driver’s suit be of the best quality fire protection It is also recommended that during an event, practice, or qualifying a driver wears the following: fire resistant shoes and socks, fire resistant hood, fire resistant underwear.
  1. Fire Control
  • It is recommended that all trucks have a built-in, fully charged fire suppression
  • All entrants should have a 10-lb. fire extinguisher in their pit
  1. Helmets; Head and Neck Restraint Devices
  • Snell SA2005 or SA2010 helmet or newer
  • Full face helmets with Lexan face shield
  • Nomex helmet skirt, and Nomex covered chinstrap
  • At all times drivers must connect their helmet to an approved head and neck restraint device/system which is SFI-approved and acceptable to track
  1. Seat Belts
  • A quick release seat belt no less than three (3) inches wide is Both ends of the lap
  • belt must be fastened to the roll cage with high quality bolts, not less than 3/8 inch in
  • Shoulder harness must be no less than three (3) inches in width and must come from behind
  • and below top of driver’s Y-type shoulder harnesses not permitted.
  • A center crotch belt must be It must be a minimum of two (2) inches wide and mount to the roll cage or seat mount.
  • Where belts pass through the seat edges, the edge must have a grommet or be rolled to prevent belt from being
  • All belts must connect in a single latch, at the lap
  • Seat belt restraint system shall not be used beyond two (2) years after their date of
  1. Seats
    • A professional racing seat is No fiberglass or plastic seats.
    • Seats must be mounted with a minimum of six (6) 3/8 inch grade 5 Two bolts at front of seat on bottom, two at bottom rear or two lower back of seat, and two at #7 shoulder bar at upper seat back.
    • Seats must have a built-in padded headrest behind
    • It is recommended that the seat also offer rib protection and have leg (5) Headrest recommended on sides of head.
  1. Roll Bars
  • Spec part required: full tubular chassis, part number:
  • Roll cage must be constructed of tubing, 1-3/4 inch x .095 inch
  • A minimum of four (4) door bars is required on the both the left and right sides of the All door bars except the bottom door bar must extend into the door skin and be convex. The bottom bar may be straight with a minimum of (3) convex door bars required on each side of truck. The door bars must have a minimum of six (6) vertical supports per side with two (2) equally spaced between each door bar.
  • The driver’s side door bars must be plated with a steel plate of not less than 1/8-inch
  • The minimum size for this plate shall be 24 inches in height and 32 inches in The plate may be a single plate or several plates cut and welded into the door bar gaps.
  • All trucks with steel covering over inside door bars on driver’s side must be
  • All areas of roll cage near driver and within his/her reach must be padded with approved padding.
  • It is recommended that the area behind the driver’s seat be plated with 1/8 inch or thicker

 

Non-conforming trucks – ASA Speed Truck or Southwest Tour Trucks Please e-mail competitors@irwindalespeedway.com for penalties or adjustments.

 

Any part found at any time during an Event that does not meet applicable Irwindale Speedway rules, is subject to impound by the Irwindale Speedway Officials. It is at the discretion of Irwindale Speedway if such part will be returned.

Irwindale Speedway Tech Officials reserve the right to make final decisions in the interpretation of any rules or race procedures at any time.  

8.15.18