2020 USRA B-MOD RULES

Published November 25, 2019

THE RULES AND/OR REGULATIONS SET FORTH HEREIN ARE DESIGNED TO PROVIDE FOR THE ORDERLY CONDUCT OF RACING EVENTS AND TO ESTABLISH MINIMUM ACCEPTABLE REQUIREMENTS FOR SUCH EVENTS.

THESE RULES SHALL GOVERN THE CONDITION OF SPEEDWAY EVENTS AND, BY PARTICIPATING IN THESE
EVENTS, ALL RACEWAY COMPETITORS ARE DEEMED TO HAVE COMPLIED WITH THESE RULES. NO EXPRESS OR
IMPLIED WARRANTY OF SAFETY SHALL RESULT FROM PUBLICATION OF, OR COMPLIANCE WITH THESE RULES
AND REGULATIONS. THEY ARE INTENDED AS A GUIDE FOR THE CONDUCT OF THE SPORT AND IN NO WAY
ARE A GUARANTEE AGAINST INJURY OR DEATH TO PARTICIPANTS, SPECTATORS OR OTHERS.

References are made throughout these regulations requiring and/or recommending that particular products meet certain specifications. These products are manufactured to meet or exceed certain criteria and are labeled as such upon satisfying those criteria. Any change to these products voids that certification. Under no circumstances may any certified product be altered from the “as manufactured” condition or such certification is voided.
Changes and additions to the 2019 USRA B-Mod rules are underlined. Changes made for grammatical purposes or to improve clarity are not highlighted. All participants and officials are expected and required to additionally be familiar with the definitions and details in the USRA General Rules, Regulations & Procedures.

The United States Racing Association shall hereafter be simply referred to as the USRA throughout the rules description. USRA official(s) shall include all personnel employed as an official by the participating racetrack.

TABLE OF CONTENTS
Article 1: Body
Article 2: Roll Cages
Article 3: Frame
Article 4: Cockpit, Steering & Seat
Article 5: Suspension
Article 6: Electrical System
Article 7: Fuel System
Article 8: Tires & Wheels
Article 9: Braking System
Article 10: Drive Shaft
Article 11: Transmission
Article 12: Rear End
Article 13: Engine
Article 14: Weight
Article 15: Safety
Article 16: Claiming Procedures

Amendments

ARTICLE 1: BODY
1.1 Plastic and/or composite body panels are not allowed.
1.2 An aluminum half-windshield may be used on driver’s side of the front window opening only.
1.3 Stock appearing front window support units must be used (painted roll bars are not acceptable
substitutes). Front window may have a support of no more than twenty (20) inches at bottom, going
straight up to top.
1.4 A minimum window opening of twelve (12) inches must be maintained on all four window openings
(front, back, left and right).
1.5 Streamlining at top of windshield is not allowed. Bodies must have standard appearing windshield
opening and corner post must follow standard configuration.
1.6 Original roof line (parallel to deck, side to side) of vehicle must be maintained with a maximum of five (5)
inches of slope from rear to front. No more than one-half (0.5) inch stiffener allowed at the rear of the
roof and must turn down perpendicular to the ground. A maximum of one (1) inch roof lips on outside
edge of roof are permitted. A maximum of four (4) inch sides on roof are permitted. Fiberglass roofs are
permitted. Aluminum roofs are permitted but must remain flat and not concaved.
1.7 Sail panels must be solid and of matching design with matching styles on both sides of racecar. Sail panel
may be no farther forward than the driver’s seat and no farther back than rear of decking. Sail panel
must be mounted within one (1) inch of the outer edge of deck and flush with the outer edge of roof. Sail
panels, side to side, may have no more than four (4) inches of variance in material length when
measured from roof line to deck.
1.8 Sail panels may have no more than four (4) inch bow from top to bottom. A maximum eighteen (18)
inches of sail panel along the roof and maximum five (5) inches tall at rear of decking and must be a
straight line from back edge of roof to back edge of deck when the sail panel is held flat. Leading edge
must within two inches of 90 degrees from roof to quarter panel.
1.9 Hood may be no more than two (2) inches above decking and must be sealed off from driver. Reverse
hood rake is not allowed. Hood must be level or slope forward toward nose of racecar. Lips on the hood
are not allowed. Hood must be flat from side to side—bowed and/or concaved designs are not allowed.
1.10 Belly pans are not allowed. A belly pan will be defined as any object or material that alters the airflow
under the racecar.
1.11 Panel(s) in front of the right door next to the engine compartment is/are not allowed. Panels under the
deck area mounted horizontal or vertical are not allowed.
1.12 Bodies with excessive damage (as determined by an official) will not be allowed to compete.
1.13 Spoilers are not allowed.
1.14 The rear deck lid and/or trunk area must be covered. Deck height may be a maximum of thirty-nine (39)
inches—NO TOLERANCE. Must have an access panel no smaller than six (6) inches wide and twelve (12)
inches long in front of fuel cell in the deck to view pull bar location. Drop decks are not allowed. Deck
may be a maximum length of one hundred twenty (120) inches from rear of engine. Deck must remain
parallel to the frame and level from side to side. Deck may have a maximum total slope of six (6) inches
with a maximum of three (3) inches of slope from racing seat to rear of deck. Doors and quarter panels
must be flush with deck. Doors and quarter panels may not be concaved towards center of car. Deck
width may be a maximum of sixty-six (66) inches and must be the same from front to rear.
1.15 Maximum overall width of nose is forty-two (42) inches top and bottom. Two (2) inch nose fins are
permitted along both sides of the nose. Nose fins may not pass the leading edge of radiator or continue
past leading edge of hood. All aluminum of the nose (including the fins) must be completely inside the
outer edges of the bumper. Nose fins must match side to side. If it is between nose fins, it is the nose; if
it separates from the hood, it is the nose.
1.16 Tires must remain the widest part of the racecar. No part of body may extend beyond the outside edge
of the tires. Exception: The lower part of the left rear quarter panel’s wheel opening’s front edge may
extend a maximum one inch outside the tire but wheel opening must remain no smaller then outside
diameter of tire.
1.17 Excluding hood and nose piece, body may extend no further forward than the back of the engine block.
Exception: Bottom of door may extend a maximum of eight (8) inches ahead of rear of block.
1.18 A maximum five (5) inch plastic skirt on bottom of doors and quarter panels and nose piece is permitted.
Body must remain a minimum of three (3) inches from ground. Engine covers are not allowed. Fins,
wings, lips or other air spoilers (other than noted) are not allowed. Any approved lip(s) must be the same
from side to side.
1.19 Bumpers:
1.19.1 Center of bumpers (front and rear) must be at least sixteen (16) inches from the ground and no more
than twenty (20) inches from ground.
1.19.2 Both front and rear bumpers must be used, and must not have any sharp edges. Any inappropriate
bumper will be disallowed by an official. Front bumper must be mounted from frame-end to frame-end
with the bottom loop parallel to ground. Bumpers must be made of a minimum of one and one-quarter
(1.25) inch diameter tubing with a minimum wall thickness of sixty-five one-thousands (.065) inch and
must be able to support the racecar if lifted by a tow vehicle. Top bar must be directly above bottom bar
(not off-centered).
1.19.3 Rear bumpers and side rail bars must not extend beyond the width of the rear tires. Tires must be the
widest part of body.
1.19.4 Rear bumpers may be constructed of tubing or flat stock, and must protect the fuel cell. Rear bumpers
may be no more than two (2) inches wider than the body on each side and may not be open-ended
(must wrap around and be connected to side rail bars).
1.19.5 Any aluminum of the nose may not extend outside of front bumper. Plastic valances and/or plastic nose
pieces are permitted but no plastic may extend in front of the bumper. Plastic may flare past the sides of
the bumper but all nose piece components must be a minimum of five (5) inches above the ground.
1.19.6 Front bumper may be a maximum width of 44 inches from outside to outside.
1.20 Appearance:
1.20.1 All racecars must be numbered with large legible numbers on both sides, on top and on the nose and real
panels. Numbers on the sides of the racecar should be in contrasting color from the body and be at least
four (4) inches thick and at least eighteen (18) inches high. Top numbers should be at least four (4)
inches thick and twenty-four (24) inches high.
1.20.2 Officials reserve the right, in the public image of the sport and/or the USRA, to assign, approve or
disapprove any advertising, sponsorship or similar agreement in connection with any event. All cars must
be neat appearing and are subject to approval of officials to compete. By competing in an event, all
drivers agree to comply with the decisions of officials in this regard.
ARTICLE 2: ROLL CAGES
2.1 The main roll cage must consist of continuous hoops of round steel tubing, and must be acceptable to
officials. Acceptable tubing is as follows: minimum one and one-half (1.5) inches diameter by ninety-five
one-thousandths (0.095) inch wall thickness for main four point roll cage. Any tubing measuring one and
three-quarter (1.75) inches diameter will be allowed a tolerance on the wall thickness for tubing
manufacturing imperfections. Any tubing under one and three-quarter (1.75) inches diameter will not be
allowed any tolerance on wall thickness. A minimum of three (3) driver side door bars must be parallel to
ground and located perpendicular to the driver to provide maximum protection for the driver, but without
causing undue difficulty in getting in or out of the racecar. Side bars must be welded to the front and the
rear of the roll cage members. Driver side door bars and uprights must be at least one and one-half (1.5)
inches in diameter at a minimum of eighty-three one-thousandths (0.083) of an inch wall thickness. Steel
door plate, 18 gauge or forty-nine one-thousandths (0.049) inch minimum thickness, must be securely
welded to outside of driver side door bars and cover area from top door bar to bottom door bar and from
rear hoop down-post to five inches in front of seat. Passenger side must have at least one cross door bar,
horizontal or angled, minimum one and one-quarter (1.25) inch O.D. with eighty-three one thousandths
(0.083) inch wall thickness, and one top horizontal door bar, minimum one and one-half (1.5) inch O.D.
with eighty-three one thousandths (0.083) inch wall thickness.
2.2 Roll bars within the driver’s reach must be padded with an accepted material as determined by an official.
Fire retardant material is highly recommended.
2.3 Installation and workmanship must be acceptable to officials.
2.4 Must be frame-mounted in at least six (6) places.
2.5 Must consist of a configuration of front and rear hoops connected by tubing on the sides or side hoops.
2.6 With helmet on and driver securely strapped into the racing seat, top of driver’s head must not protrude
above the roll cage. A cross bar in halo is required.
2.7 Must have a protective screen or bars in front window opening in front of driver’s face.
2.8 Protection of driver’s feet utilizing a bar across the back of the engine with vertical bars and rub rails or
similar protection is mandatory.
2.9 Brace bars forward of roll cage may not be higher than the stock hood height.
2.10 Adjustable bars on the frame and/or roll cage are not allowed. Removable bars are permitted.
ARTICLE 3: FRAME
3.1 Factory production complete full 1960 or newer parallel American passenger car frames only. Frames may
be cut in rear only at a point not further than thirty-six (36) inches from center of rear end housing.
3.2 May only be altered for the installation of springs and shocks. Top of frame may not be altered for upper
“A” frame clearance.
3.3 All components must be made of steel and be properly welded.
3.4 Must be full and complete on both sides, may not be widened or narrowed and must be able to support
roll cage on both sides. All factory holes must be present for inspection. All measurements must meet the
frame diagram tolerances listed or be within one-half (0.5) inch (either way) of OEM measurements on
any measurement not listed on frame diagram—NO TOLERANCE.
3.5 Minimum height from ground is four (4) inches. Exception: Front cross member may be notched for
radiator clearance only. Outside frame rails may not be raised. (See measurement “L” on frame diagram)
3.6 Rear of frame may be altered to accept leaf or coil springs.
3.7 Hydraulic, ratchet or electric weight jacks are not allowed anywhere on the racecar. Aluminum jack bolts
are not allowed.
3.8 Wheelbase must be a minimum of one-hundred eight (108) inches on both sides and a maximum of onehundred twelve (112) inches on both sides (no tolerance).
3.9 Tubular front clips are not allowed.
3.10 Overall width of the racecar may not exceed seventy-eight (78) inches. Width shall be measured from the
widest points on each side of the racecar (the tires).
3.11 Rear of engine (bell housing flange) must be mounted at least seventy-two (72) inches forward from the
center line of the rear axle—NO TOLERANCE.
ARTICLE 4: COCKPIT, STEERING & SEAT
4.1 Loose objects and/or weights are not allowed.
4.2 Air bags are not allowed.
4.3 Rear view mirrors are not allowed.
4.4 Floor and firewall must be complete in the driver’s compartment. Minimum 0.125 inch aluminum, or
0.060 inch steel, complete floor pan required. .Interior sheet metal cannot be higher than or enclose a
standard window opening. Sheet metal in the driver’s compartment must be horizontal from the top of
the driver shaft tunnel to the right side door bars or angle from the top of the drive shaft tunnel upwards
to the top of the right side door bars. Driver must be able to exit the racecar from both sides.
4.5 Steering:
4.5.1 Must be OEM and remain within original bolt pattern for type of frame used. Idler arm, pitman arm and
center link must match frame. Outer tie rod end and adjustment sleeve may be replaced with a heim end
and steel tube.
4.5.2 Rack and pinion is not allowed.
4.5.3 600 steering gear boxes are not allowed.
4.5.4 May be modified to suit driver, but must remain on left side of cockpit (no center steering).
4.5.5 Quick-release metal coupling on steering wheel is mandatory. Plastic couplings are not allowed.
4.6 Seat:
4.6.1 Factory-manufactured racing seats are mandatory, and must be acceptable to officials.
4.6.2 Homemade aluminum, plastic or fiberglass seats are not allowed.
4.6.3 Must be properly installed and seat back cannot be moved back further than rear edge of quarter post.
4.6.4 High-back aluminum seats only. Full containment racing seats are strongly recommended.
ARTICLE 5: SUSPENSION
5.1 Front suspension must remain stock-type for the type of frame being used. Lower A frame must be
unaltered stock stamped steel and in OEM location and remain OEM dimensions with OEM type bushings
only. Mono ball or heim style bushings are not allowed. One-piece steel, rubber, polyurethane or nylon
bushings only No offset or bearing type bushings allowed. Inner steel sleeve in bushing must be present.
Screw-in ball joints are permitted. GM 1978-1988 metric “G” body frames are allowed to use Nova lower
“A” frames. Front suspension travel limiting devices are not allowed. Front suspension must travel freely
in both directions from ride height measured at the shock.
5.2 Aluminum and/or titanium components are not allowed. Magnet must stick to all components Exception:
aluminum cross shafts are permitted. Stainless steel is permitted. Gun-drilled, tubular and/or hollow bolts
or studs are not allowed anywhere on the racecar.
5.3 Steel tube-type upper A-frames are permitted and may be moved.
5.4 Stock unaltered passenger car spindles only, must match side to side make and dimensions. Fabricated
spindles are not allowed.
5.5 Front sway bars may be used. Must be made of steel and may be attached to the bottom A-frame using
steel Heim joints. Must be solid full-length OEM.
5.6 A solid rear panhard bar or solid J-bar may be used. J-bar must be mounted to right side of pinion and go
over the top of the driveshaft to left side of the chassis. Must be made of steel and may be attached by
using a minimum three-quarter (0.75) inch i.d. steel Heim joint. Minimum length must be nineteen (19)
inches measured from center of Heim to center of Heim.
5.7 Two-link suspension only. Four-link type suspensions are not allowed. All suspension bars and/or arms
must remain solid and straight, a minimum fifteen (15) inches from center of Heim and must mount on
the bottom side of rear end housing. Swing arms are not allowed. Solid pull bars only and centerline of
pull bar must be mounted above driveshaft and within one (1) inch of driveshaft centerline.
5.8 Suspension or rear-end parts, including jack bolts and mounting brackets, must be made of steel. Lift
arm is not allowed. Spring and suspension covers are not allowed. Tarps and/or covers on racecar are
not allowed outside of your pit area.
5.9 Floating suspensions are not allowed. All bird cages and/or brackets must be welded to the rear-end
housing.
5.10 A tether chain is permitted on front and rear suspension. Chain must be mounted from lower A-frame to
frame on front end and on top of axle tube to frame on rear end. Chains must be mounted vertical and
solid and must remain loose at ride height. Only left side rear chain may utilize a rubber biscuit. Springs
of any kind are not allowed on chains.
5.11 Shocks & Springs:
5.11.1 One (1) shock per wheel is permitted and rear shocks must be mounted within twenty five(25) degrees
of vertical. Only conventional type (closed on one end) single shaft shocks are permitted. Rear end
dampener shocks are not allowed. Rear shocks may be mounted on a weight-jack-type adjustable bolt.
5.11.2 Shock shaft must be able to compress all the way into shock body. Shocks must have a minimum of
seven (7) inches of travel. Shock shaft must move in both directions from its installed position at ride
height. Shock cannot preload the spring.
5.11.3 Shock covers are permitted but may cover only front half of shock and must be mounted directly to
shock. Bump stops (internal or external) are not allowed. Shock rubber stoppers on the right front are
not allowed.
5.11.4 Steel shock mounting bolts only. Aluminum and/or titanium is not allowed.
5.11.5 Coil-over, remote and/or air reservoir shocks are not allowed. Canister and/or adjustable shocks are not
allowed. Bulb-type shocks are not allowed. Air shocks are not allowed. Aluminum shocks are not allowed.
Inerter shocks, J-damper shocks, active mass damper shocks and/or through-rod-designed shocks are
not allowed. Dummy shocks are not allowed. Aluminum shaft guides are permitted.
5.11.6 Bladder-type valves and/or Schrader valves are not allowed. Shocks shall be subject to claim, as outlined
in Claim Procedures (see Article 16).
5.11.7 One spring slider on each rear wheel is permitted. Coil springs must be at least four and one-half (4.5)
inches outside diameter. Steel springs only. Torsion bars are not allowed in rear. Spring rubbers are not
allowed. Progressive, tapered, stacked and/or welded springs are not allowed.
5.11.8 Leaf Spring Rule: Must use steel, multi-leaf springs. Must be same number of full springs on each side
(half springs are not allowed). Additional suspension components are not allowed. Adjustable lowering
blocks are permitted.
5.11.9 Mono-Leaf Spring Rule: Must utilize coil springs centered on top of rear-end housing.
5.11.10 Must adhere to either Leaf Spring Rule or Mono-Leaf Rule. Mixing and matching is not allowed.
ARTICLE 6: ELECTRICAL SYSTEM
6.1 Battery:
6.1.1 Must be securely mounted inside frame rails and covered.
6.1.2 One (1) 12-volt battery only (no 16-volt batteries).
6.1.3 Voltage converters are not allowed.
6.1.4 All battery posts must be securely covered.
6.2 Ignition:
6.2.1 Must utilize OEM distributor and ignition. Stock-appearing coils, coil covers and modules only. Square coil
covers are not allowed. Multiple spark ignitions are not allowed. Crank trigger ignitions are not allowed.
GM external coils are not allowed. All ignition parts must remain out of the reach of the driver.
6.2.2 Kill switch required within easy reach of the driver. The switch must be clearly marked “OFF” and “ON”.
6.2.3 GM must utilize OEM GM HEI distributor. Chrysler and Ford may use aftermarket HEI (bushing type only).
Roller bearings are not allowed. Must utilize stock-type components.
6.2.4 Open circuit board modules are not allowed.
6.3 Digital gauges are not allowed. Digital tachometers are permitted. Cameras pointing to any moving or
suspension parts are not allowed. Except for memory recall tachometer, electronic monitoring computer
devices capable of storing and/or transmitting information are not allowed.
6.4 Wiring elements must be accessible for technical inspection. Any racecar advancing spots and missing will
be subject to disqualification.
6.5 All standard engines (see Rule 13.7) must utilize a soft-touch rev control box MSD part #8727CT with a
7,200 RPM maximum limit. All crate engines (see Rule 13.6) and concept engines (see rule 13.8) must
utilize a soft-touch rev control box MSD part #8727CT with a 6200 RPM maximum limit This must be out
of reach of the driver but easily accessible for inspection at all times. MSD part #8727CT rev control box
is required with unaltered wiring harness and will be required on all race cars. Ground wire must be
visible for inspection and it is recommended that it be mounted near or on the distributor.
6.6 Transponders must be mounted vertically on or behind engine mid-plate, less than two (2) feet from the
ground and unobstructed by any metal.
ARTICLE 7: FUEL SYSTEM
7.1 Fuel:
7.1.1 Automotive gasoline, racing gasoline is permitted. Oxygenated fuel is not allowed; however an ethanol
blend is allowed up to 85%. Additives of any kind are not allowed. Penalty for illegal fuel is loss of points,
cash and awards earned for that event and subject to a fine.
7.1.2 May not be blended with ethers or other oxygenates, and may not be blended with aniline or its
derivatives, nitro compounds or other nitro containing compounds. Fuel is tested using a Digitron
dielectric meter. It is the responsibility of the driver and/or owner to have fuel tested.
7.1.3 Upper cylinder lubricants are not allowed.
7.2 Electric fuel pumps are not allowed. Belt driven fuel pumps are not allowed. Pumps must bolt to block in
stock location.
7.3 Carburetor:
7.3.1 Must be naturally aspirated.
7.3.2 Fuel injection is not allowed. Aerosol carburetors are not allowed.
7.3.3 The Standard Engine must utilize a gauge-legal, unaltered Holley 500 CFM two-barrel (part #4412). HP
carburetors are not allowed. Aftermarket metering blocks are permitted. Grinding and/or polishing of any
kind is not allowed. All carburetor components must be for a Holley 500. Milling and/or grinding of
throttle shaft is not allowed, and shaft must stay round. The choke and air horn may be removed (this is
the only reworking permitted). Casting line at venturi must be present. Boosters must remain centered in
venturi and may not be raised or lowered. Annular discharge boosters are not allowed.
7.3.4 Crate engines and concept engines are permitted to use a Holley 4150 Series four-barrel carburetor.
HP carburetors are permitted. This carburetor has no size requirements but must remain to function as
the 4150 series carburetor was designed and must utilize Holley type boosters. Vacuum secondary
carburetors are not allowed. Annular discharge boosters are not allowed.
7.3.5 A one (1) inch adapter plate or spacer is permitted. Distance between bottom of carburetor and top of
intake manifold cannot exceed one and one-quarter (1.25) inch. Spacer thickness must remain the same
front to back and side to side.
7.3.6 Carburetors shall be subject to claim, as outlined in Claiming Procedures (see Article 16).
7.4 Fuel Cell:
7.4.1 Must be commercially manufactured and must be mounted utilizing at least two (2) steel straps. Straps
must be two (2) inches wide at all measuring points.
7.4.2 Must be enclosed in a steel container and must be protected in rear of axle by roll cage tubing mounted
securely.
7.4.3 No part may be lower than protective tubing. Protective tubing must be no wider than six (6) inches on
both sides. Fuel cell may be no lower than ten (10) inches from the ground.
7.4.4 Must have check valves. A ball-type, flapper or spring or filler rollover valve is mandatory for fuel cells
without a positive seal filler neck/cap system.
7.4.5 Limited to a maximum capacity of thirty-two (32) gallons.
ARTICLE 8: TIRES & WHEELS
8.1 Wheels:
8.1.1 Must be fifteen (15) inches in diameter and eight (8) inches in width.
8.1.2 Bleeder valves are not allowed.
8.1.3 Must be reinforced steel only.
8.1.4 A steel bead lock may be used on the right side wheels only, and may be mounted on the outside of the
wheel so long as it does not add to the overall width of the wheel.
8.1.5 Homemade mud caps are not allowed.
8.1.6 Wheel covers are permitted on right side wheels only. Inner mud plugs are permitted.
8.1.7 Wide five wheel adaptors are not allowed. Steel lug nuts only are permitted.
8.1.8 Spacer between hub and wheel is permitted, but must be made of aluminum only and overall width of
racecar cannot exceed 78 inches.
8.1.9 Added ballast to any wheel is not allowed.
8.1.10 Solid and/or non-spoked wheels are not allowed.
8.2 Tires:
8.2.1 The only tire permitted is the American Racer G60-15 KK704 (Short, Tall or X Tall). Tires must durometer
50 or harder at the conclusion of any race. Any tire not meeting this durometer reading is subject to
having a tire sample sent in for chemical testing.
8.2.2 Softening is not allowed. Solvents of any kind are not allowed. Altering tires with any components or
chemicals which alter the manufacturer’s baseline-settings of the tire is not allowed.
8.2.3 Grooving and/or siping is permitted.
8.2.4 Sidewall markings must remain visible. Buffing and/or removing compound designations is not allowed.
8.2.5 Added ballast to the inside of any tire is not allowed.
8.3 Tire Testing Procedures:
8.3.1 Random GC (gas chromatography) scans may be performed to identify illegal substances. A GC scan
should always be a peak in 19-20 minutes. If there is no peak, the driver will be disqualified. Driver may
protest the GC scan results and request a mass spec test at the cost to the driver (usually around $300).
The mass spec test will reveal exactly what substance was used. The main peak of the tire should never
be in half.
8.3.2 Traces of chemicals and/or excessive quantities of chemicals found to be outside the baseline on any test
shall result in the penalties declared in Section 2.15.5 of the USRA General Rules, Regulations &
Procedures plus an additional indefinite financial penalty and indefinite length of suspension. This penalty
also applies to driver refusal of a tire test. Refusal of tire test shall be treated the same as an infraction.
Official(s) may inspect any tire on the racecar and/or any tire in possession of the driver in his/her pit
area and/or hauler (in other words, if you have “doped” tires then do not even bring them to the track).
8.3.3 It is strongly recommended that all drivers use only soap and water. Baking tires will not eliminate traces
of illegal substances. The USRA will aggressively test for illegal substances and will levy severe
punishment for infractions relating to tires.
ARTICLE 9: BRAKING SYSTEM
9.1 Must be operating on all four wheels and must lock up all four wheels during inspection.
9.2 Must have caliper and rotor on all four wheels. Caliper and rotor must be standard size and weight.
Vented rotors are required on front and rear wheels.
9.3 Electronic brake actuators are not allowed. Brake shut-offs are not allowed.
9.4 Calipers may not be lightened, must be OEM, made of steel and must match front to front and rear to
rear. Brake pads may not be altered or lightened and must match side to side.
9.5 Rotors must be steel and may not be lightened, scalloped, slotted or drilled. Rotors may be re-drilled for
different bolt patterns or larger studs. Oil bath hubs are not allowed.
9.6 Front-to-rear brake bias is permitted (no left to right).
9.7 Brake floaters are not allowed.
9.8 Brake lines must be visible.
9.9 Must maintain minimum OEM dimension for hubs, rotors, pads and calipers.
ARTICLE 10: DRIVE SHAFT
10.1 A loop is required and must be constructed of at least one-quarter (0.25) inch by two (2) inches solid
steel. Loop must be mounted no more than six (6) inches from the front of the drive shaft tube.
Alternatively, two (2) loops of one-quarter (0.25) inch by one (1) inch solid steel fastened to cross
member are permitted.
10.2 Must be a minimum two (2) inches in diameter.
10.3 Must be painted white.
10.4 Aluminum drive shafts are not allowed.
10.5 Carbon fiber drive shafts are permitted but must be painted white.
ARTICLE 11: TRANSMISSION
11.1 OEM three-speed, four-speed and five-speed and automatic production-types are permitted. With engine
running and racecar in stationary position, driver must be able to engage racecar in gear and then move
forward and then backward at time of inspection.
11.2 “In and out” boxes are not allowed. Ball spline transmissions are not allowed.
11.3 May all be clutch-operated or an OEM automatic with a coupler. May use a hand or clutch pedal operated
ball valve for neutral.
11.4 Aftermarket transmissions are permitted.
11.5 Approved aftermarket transmissions are Bert (Part #LMZ/GEN II), Brinn (Part #70001), Falcon (Part
#60100) and RaceGator (Part #140002/140002-C) and Mitchell Machine Bullet Tranny with internal
clutch.
11.6 Clutch must be inside of bell housing for OEM production-type transmissions (except as noted in Rule
11.4).
11.7 Starter must bolt to engine block or factory location.
11.8 One (1) forward gear and one (1) reverse gear must be in working order, plus a neutral position, and
must be able to be shifted by driver.
11.9 Aluminum flywheel is permitted. Must have full-sized explosion proof, aluminum or steel bell housing.
Aluminum must be SFI approved (Note: GM bell housing is not SFI approved). Flywheel must bolt to
crankshaft. Clutch must bolt to flywheel, a minimum six and one-quarter (6.25) inch clutch.
11.10 Automatic and aftermarket transmissions must have a guard two-hundred seventy (270) degrees around
flex plate or flywheel, and must be constructed of at least one-quarter (0.25) inch steel. Alternatively,
automatic and/or aftermarket transmissions may utilize an SFI-certified aftermarket guard. Flex plates
must be SFI certified.
11.11 Internal clutches are not allowed except for approved aftermarket transmissions.
ARTICLE 12: REAR-END
12.1 Any passenger car- or truck-type is permitted. Aluminum is not allowed except lowering blocks, axle cap,
U-joint caps and drive plate.
12.2 Nine (9) inch Ford rear-end is permitted (floater recommended).
12.3 Quick change rear-end is permitted with steel axles and steel axle tubes only. Must use a ten (10) inch
ring gear and minimum one (1) inch wide solid spur gears.
12.4 Cambered rear-ends are not allowed (one-piece drive flange only).
12.5 Traction devices are not allowed (includes Gold Track, True Track or similar type components).
12.6 Rear of engine (bell housing flange) must be mounted at least seventy-two (72) inches forward from the
center line of the rear axle—NO TOLERANCE.
ARTICLE 13: ENGINE
13.1 Overflow tubes must be directed toward the ground and inside the frame rails.
13.2 Radiator must be mounted in front of engine. Aluminum pulleys and radiators are permitted.
13.3 All belt driven components must be mounted on front of engine. Electric water pumps and/or fans are
not allowed. Engine oil coolers are not allowed. Air pumps are not allowed.
13.4 Exhaust & Mufflers:
13.4.1 Tri-Y headers are not allowed. Round tube headers only. All primary tubes must enter one collector at the
same point. Concept Engines must utilize non-stepped headers only. Standard Engines and Crate Engines
may utilize stepped headers. Header wrap is not allowed.
13.4.2 Exhaust system and/or mufflers must be mounted in such a way as to direct spent gases away from the
cockpit and away from areas of possible fuel spillage. Exhaust through body panels or fenders is not
allowed.
13.4.3 Mufflers are recommended. Mufflers may be required at track’s discretion.
13.4.4 Exhaust sensors, merge collectors, dividing collectors, venturi collectors and/or extension cones are not
allowed. Collector extension and/or muffler and turn down may not exceed twenty-four (24) inches and
must maintain a consistent inside diameter.
13.4.5 Zoomies, Crossovers and/or 180s are not allowed.
13.4.6 Oil pan evac systems are permitted but must enter exhaust header from the side of the collector only.
External pump systems are not allowed.
13.6 OPTION #1 – Crate Engine:
13.6.1 GM Performance Parts (GPP) factory-sealed CT350 Chevy small block crate engine (Part No. 88958602 or
19258602): includes four-bolt-main block, 9.5:1 hypereutectic pistons, cast iron crankshaft, GM iron
Vortec cylinder heads, high-rise dual-plane intake manifold, 8-quart single kick-out circle track oil pan,
valve cover kit with breather tube and breather, unique dual-pattern cam and special “kool nut” rocker
arm nut design.
13.6.2 May utilize one (1) Holley 4150 Series four-barrel carburetor (see Article 7.3.4). Use of a spacer between
carburetor and intake is optional, but spacer may be no more than one (1) inch thick and may not be
throttle bore adjustable. Aerosol carburetors are not permitted. Carburetors shall be subject to claim
(crate to crate only) as outlined in Claim Procedures (see Article 16).
13.6.3 Must utilize soft-touch rev control box with a 6,200 RPM limit. This must be out of reach of the driver but
easily accessible for inspection at all times. Any driver caught altering the chip or ignition system in any
way so as to defeat the chip rule shall receive a 30-day suspension, loss of all track and national points
for the night and a $1,000 fine for the first offense. Second offense shall be a one-year suspension, loss
of all track and national points for the season and a $2,000 fine.
13.6.4 Must have “Crate” sticker on racecar or crate engine is claimable. Any driver running a “Standard” engine
with a “Crate” sticker will be disqualified. Any driver running with a crate motor will not be eligible to
claim in that season. Any driver that claims a standard engine and switches to crate engine will be eligible
to be claimed.
13.6.5 Must be unaltered and sealed from factory at appropriate points (intake, head, timing chain cover and oil
pan) with approved GPP break-off bolts. Any altered, damaged or missing GPP break-off bolts will result
in driver being disqualified from that event, loss of all track and national points accumulated up to, and
including, the date of the offense, and a $2,000 fine and fourteen (14) day suspension from all USRAsanctioned events. Second offense carries a $5,000 fine and one (1) year suspension.
13.6.6 GM seal bolt exception is USRA, USMTS or approved rebuild seals (call 515-835-9946 for verification).
13.6.7 Crate Engine is not subject to claim.
13.7 OPTION #2 – Standard Engine:
13.7.1 Must be stock appearing. Any American make is permitted. Absolutely no changes allowed. Must use
stock firing order for that make and model (GM to GM, Ford to Ford, etc.). Titanium is not allowed.
13.7.2 May be a maximum of 360 cubic inches. (370 c.i. for Chrysler).
13.7.3 Must be a maximum 9.5:1 compression. Exception: 302-, 305-, 307- and 318-cubic-inch engines may run
10.5:1 compression. Only flat top or dished pistons are permitted.
13.7.4 Must appear strictly stock for that model and make and in the original mounts. Parts for 400 cubic inches
or larger are not allowed. Stroke must match block. Block casting number must remain visible.
13.7.5 Only stock appearing crankshafts are permitted. Lightweight cranks are not allowed. No undercut, bull
nosed, gun drilled or knife edge crankshafts allowed.
13.7.6 Lightweight, aluminum and/or fluid dampeners are not allowed
13.7.7 GM five and seven-tenths (5.7) inch or six (6) inch rods are permitted. Must be stock appearing I-beam
non-polished rod. Aluminum or light weight is not allowed. Cap screw rods are permitted
13.7.8 A minimum one (1) inch plug above the oil level in the side of the oil pan is recommended. If not utilizing
a one (1) inch plug, oil pan may have to be removed at time of inspection.
13.7.9 Only stock, unaltered two-barrel low rise cast iron intake manifolds or Approved aluminum intakes are
permitted. Approved aluminum intakes are GM - Edelbrock (#2101 or #2701) or Weiand (#7547 or
#7547-1); Ford - Edelbrock (#2121 or #2181 or #2665) or Weiand (#7515 or #8023 or #7516);
Chrysler – Edelbrock (#2176) or Weiand (#7545 or #8022). Porting, polishing or port machining is not
allowed. Bowtie, aftermarket, SVO and W2, marine, VORTEC or other special production intake manifolds
are not allowed. External cooler lines from back of intake to front of intake is permitted.
13.7.10 Cast iron stock production or aftermarket steel stock replacement heads are permitted. Porting and/or
polishing is not allowed. GM cars must utilize 76cc heads (approved head numbers are 336, 339, 388,
441, 454, 487, 624, 813, 882, 991 and 993). Aftermarket head numbers are: GM – EQ Part #CC167ES2
or #CH350I; Dart Part #10024267 or #10024360; World Products Part #043600 or #042670; Ford
– World Products Part #53030; Chrysler – EQ Part #CH138B; RHS/Indy Part #20300 or #20301. Heads
may be flat milled to reach the 9.5:1 compression rule. Valve size no larger than 2.02 intake and 1.60
exhaust. VORTEC heads are not allowed. Beehive valve springs are not allowed.
13.7.11 Screw-in studs, guide plates and poly-locks are permitted.
13.7.12 Roller cams and lifters are not allowed. Roller rocker arms are not allowed (stock-type stamped steel
rocker arms or cast steel rocker arms only). Roller tip rocker arms are permitted. Chryslers may utilize
OEM steel shaft rockers but may not exceed one hundred twenty (120) pounds of valve spring seat
pressure and must maintain OEM valve spring dimensions. Under valve cover pressurized valve train
oiling systems are not allowed.
13.7.13 Mushroom lifters are not allowed (stock diameter only). Must match make and model.
13.7.14 Stud girdles are not allowed.
13.8 OPTION #3 – Concept Engine:
13.8.1 Must be stock appearing. Any American make is permitted. Absolutely no changes allowed. Must use
stock firing order for that make and model (GM to GM, Ford to Ford, etc.). Titanium is not allowed.
13.8.2 May be a maximum of 360 cubic inches. (370 c.i. for Chrysler).
13.8.3 Must be a maximum 9.5:1 compression. Only standard weight (minimum 450 grams) flat top or dished
pistons are permitted. Must use standard weight wrist pins (minimum 130 grams). Must use minimum
1.5mm, 1.5mm, 3mm piston rings. Maximum six one hundredths (.06) inch oversized allowed.
13.8.4 Aftermarket and splayed main cap blocks are not allowed. Grinding, polishing, painting or coating of
internal engine parts are not allowed. Altering lifter bores are not allowed. Lifter bore valley vent tubes
are not allowed. Block casting number must remain visible.
13.8.5 Only stock appearing crankshafts are permitted. Lightweight cranks are not allowed. No undercut, bull
nosed, gun drilled or knife edge crankshafts allowed. Balancing permitted by drilling only. Resizing
journals to a maximum .030 inch under is permitted. Stroke must match block.
13.8.6 Lightweight, aluminum and/or fluid dampeners are not allowed. Any stock OEM steel balancer is
permitted.
13.8.7 Must be stock appearing I-beam non-polished connecting rod. Aluminum or light weight is not allowed.
Only an OEM Length rod is allowed. Cap screw rods are permitted. Minimum weight of 530 grams is
required.
13.8.8 Steel oil pans only with a minimum one (1) inch plug above the oil level in the side of the oil pan. If not
utilizing a one (1) inch plug, oil pan may have to be removed for inspection. Wet sump oil systems only.
13.8.9 Only stock, unaltered two-barrel low rise cast iron intake manifolds or Approved aluminum intakes are
permitted. Approved aluminum intakes are GM - Edelbrock (#2101 or #2701) or Weiand (#7547 or
#7547-1); Ford - Edelbrock (#2121 or #2181 or #2665) or Weiand (#7515 or #8023 or #7516);
Chrysler – Edelbrock (#2176) or Weiand (#7545 or #8022). Porting, polishing or port machining is not
allowed. Bowtie, aftermarket, SVO and W2, marine, VORTEC or other special production intake manifolds
are not allowed. External cooler lines from back of intake to front of intake is permitted.
13.8.10 Cast iron stock production or aftermarket steel stock replacement heads are permitted. Porting and/or
polishing is not allowed. GM cars must utilize 76cc heads (approved head numbers are 336, 339, 388,
441, 454, 487, 624, 813, 882, 991 and 993). Aftermarket head numbers are: GM – EQ Part #CH350I;
Dart Part #10024267 or #10024360; Ford – World Products Part #53030; Chrysler – EQ Part #CH138B.
Heads may be flat milled to reach the 9.5:1 compression rule. Valve size no larger than 2.02 intake and
1.60 exhaust. VORTEC heads are not allowed. Intake valves must weigh a minimum one hundred three
(103) grams. Exhaust valves must weigh a minimum eighty seven (87) grams. Only stock diameter valve
springs are permitted. Beehive valve springs are not allowed. Only stock steel valve spring retainers
permitted.
13.8.11 Screw-in studs, guide plates and poly-locks are permitted.
13.8.12 Roller cams and lifters are not allowed. Only flat tappet hydraulic camshafts with forty-five one
hundredths (0.45) inch maximum lift are permitted. Roller Rocker arms are not allowed (stock-type
stamped steel rocker arms or cast steel rocker arms only). Roller tip rocker arms are not allowed. Must
maintain an OEM rocker arm ratio (1.5 for GM). Chryslers may utilize OEM steel shaft rockers but may not
exceed one hundred twenty (120) pounds of valve spring seat pressure and must maintain OEM valve
spring dimensions. Under valve cover pressurized valve train oiling systems are not allowed.
13.8.13 Mushroom lifters are not allowed. Steel stock diameter lifters only and lifter must collapse one-tenth (0.1)
inch minimum.
13.8.14 Stud girdles are not allowed.
13.8.15 Any Holley 4150 Series four-barrel carburetor is permitted (see Article 7.3.4).
13.8.16 Only non-stepped headers are permitted. Must follow all header rules (See Rule 13.4).
13.8.17 May utilize a four-hole carburetor spacer with a maximum one inch height and a maximum 1.693 inch
straight thru holes and a maximum three-eighths (0.375) inch of gasket material between carburetor and
intake.
13.8.18 Must utilize a rev limiter with a maximum setting of 6,200 RPM (See Rule 6.5).
13.8.19 Overall racecar weight must be a minimum two-thousand five hundred (2,500) pounds
13.8.20 Must have “Concept” sticker on racecar, otherwise engine is claimable. Any driver utilizing a concept
engine will not be eligible to claim in that season. Any driver that claims a standard engine and switches
to concept engine will be eligible to be claimed.
13.8.21 Concept engines are not subject to claim.
13.8.22 All USRA fuel rules apply.
ARTICLE 14: WEIGHT
14.1 The overall weight of the racecar shall be measured at the conclusion of an event with the driver in the
cockpit, wearing complete racing apparel. All racecars must display weight at which it will compete on
both windshield posts. Must be two (2) inches tall and in contrasting color to the racecar. Any racecar not
displaying their weight will be required to weigh the maximum weight for this class and required to add
any weight in any location required in this class.
14.2 Overall weight of the racecar must be a minimum of two-thousand five hundred (2,500) pounds.
14.3 Ballast:
14.3.1 May not be mounted in cockpit, outside of body or hood area, or on any rotating parts. Weight must be
mounted to the frame, roll cage or rear-end housing only. Weight brackets for rear-end housing must be
made of steel.
14.3.2 Must be securely mounted, painted white and clearly marked with the car number.
14.3.3 Must be attached with at least two (2) one-half (0.5) inch bolts with a maximum of one hundred (100)
pounds per mounting. Any ballast weighing twenty-five (25) pounds or less may be mounted with one (1)
one-half (0.5) inch bolt.
14.3.4 May not be attached to rear bumper.
14.3.5 Any part of the racecar that may be deemed “added ballast” is subject to all ballast rules.
ARTICLE 15: SAFETY
15.1 It is recommended that each racecar have built-in fire extinguishing equipment, but cannot be of the dry
powder type (must be Halon 1211 or equivalent).
15.2 Drivers should have in their pit area as part of their equipment, at all times, a fully charged dry chemical,
Halon (or its equivalent) fire extinguisher. Ten- or thirteen-pound fire extinguishers are recommended.
15.3 Driver must wear required helmet, fire suit and five-point safety harness whenever the racecar is on the
racetrack. This includes during track packing, warm ups, hot laps and races.
15.4 Helmets are mandatory and must be certified SA2010 or SA2015.
15.5 Helmet must accompany driver and racecar at time of inspection.
15.6 Complete one- or two-piece fire suits of a flame retardant nature are mandatory.
15.7 Fire-resistant gloves and shoes are mandatory. Fire-resistant socks are recommended.
15.8 The use of a five- six- or seven-point driver restraint system (safety belts, sub-belt and shoulder harness)
is required. Factory-type shoulder belts or straps are not allowed. The use of a seven-point driver
restraint system is recommended.
15.9 Metal to metal buckles are required on shoulder and seat belts.
15.10 Shoulder harness must be mounted securely to the main roll cage.
15.11 Where the belt passes through the seat edges, a grommet must be installed, rolled and/or padded to
prevent cutting of the belt.
15.12 Driver restraint system must be less than three (3) years of age past the date of manufacture. It is
recommended that the driver restraint system be no more than two (2) years of age past the date of
manufacture.
15.13 Full-size window net mounted in the left side driver’s window opening is required. Window net mounts
must be welded to the roll cage. All bars around the driver must have approved roll bar padding.
Approved racing arm restraints are recommended.
15.14 Fire-resistant safety neck collars are mandatory.
15.15 Absolutely no plastic except from edge of firewall to body skin and inner wheel tub to body skin.
ARTICLE 16: CLAIMING PROCEDURES
16.1 Any driver possessing a valid USRA license may have the opportunity to execute a claim on the cylinder
heads and intake manifold, shocks or carburetor of another driver’s racecar. Crate Engines and Concept
Engines are not claimable. Drivers utilizing a Crate Engine or Concept Engine are not eligible to claim
another driver’s cylinder heads and intake manifold. Any driver running with a Crate Engine or Concept
Engine will not be eligible to claim another driver’s cylinder heads and intake manifold in that season. Any
driver that claims a standard engine and switches to a Crate Engine or Concept Engine will be eligible to
have their cylinder heads and intake manifold claimed.
16.2 The first four (4) finishers in the main event must drive their racecars directly to the designated claim
area at the conclusion of the main event, and are subject to being claimed by any other driver that
finishes fifth or lower and finishes on the same lap as the winner. Any of the top four finishers that do
not go to the claim area will be disqualified, but are still subject to being claimed.
16.3 Claims must be made within five (5) minutes of the completion of the main event. Claimed items must be
removed at the racetrack and within one (1) hour after claimed driver accepts the claim.
16.4 Driver making claim must drive his/her race car immediately after finish of feature, under its own power,
directly to the claim area.
16.5 Claiming driver must present license and cash to official overseeing the claim area at the time that the
driver declares his/her intention to claim. The cash price of the claim for cylinder heads and intake
manifold shall be $500. The cash price of the claim for carburetors shall be $300 or $150 and exchange.
Only four-barrel for four-barrel and/or two-barrel for two-barrel claims are permitted. The cash price of
the claim for shocks shall be $50 per shock. Drivers claiming shocks may claim one or more shocks
during a single claim.
16.6 The cylinder heads and intake manifold claim includes both cylinder heads and intake manifold, rocker
arm studs and guide plate, valves, valve springs, retainers and keepers, and intake bolts. This claim does
not include carburetor spacer, valve covers, rocker arms, pushrods, thermostat and thermostat housing,
any fittings, adapters, studs or head bolts.
16.7 Claiming driver shall select from the first four (4) finishers in the main event, and must declare that
choice to the official overseeing the claim area. If the claiming driver decides at that time that he/she
does not wish to execute the claim, he/she will nonetheless be charged one claim. If multiple drivers
declare an intention to claim, the driver finishing farthest back in the main event will select first. If the
claimed driver is utilizing a non-claimable engine, the claiming driver may not choose another driver and
will not be charged a claim.
16.8 Driver is permitted one (1) claim per event, regardless of the outcome of that claim.
16.9 Only drivers, car owners and officials are permitted in the designated claim area. Any other participants
associated with that racecar that enter the claim area will be subject to disqualification, fine and/or
suspension.
16.10 Only a driver may claim, and only the claimed driver or car owner may agree to accept or refuse the
claim. The first statement of acceptance or rejection of the claim by the claimed driver or car owner is
binding.
16.11 Any driver or car owner refusing to accept a claim will forfeit all cash and contingency winnings for that
event.
16.12 Any driver or car owner refusing to accept a claim forfeits his/her right to make a claim in any USRA
event for a period of one (1) year from the date of refusal.
16.13 Any driver or car owner refusing to accept a claim will forfeit all USRA points (national and track)
accumulated up to, and including, the event at which the claim was made.
16.14 First refusal to accept a claim will result in that driver and car owner being suspended from all USRA
events for thirty (30) days and until a $1,000 fine is paid and received at USRA headquarters. Second
refusal to accept a claim will result in that driver and car owner being suspended from all USRA events
for one (1) year and until a $5,000 fine is paid and received at USRA headquarters.
16.15 In the event of a dispute between driver and car owner whether to accept or refuse a claim, the decision
of the driver shall overrule that of the car owner.
16.16 Any driver found to be making a claim for another person will lose all USRA points (national and track)
accumulated to date for the entire season, all cash and contingency winnings for that event, and will be
suspended from all USRA events for thirty (30) days and until a $1,000 fine is paid and received at USRA
headquarters.
16.17 Sabotage of claimed parts will result in driver being suspended from all USRA events for fourteen (14)
days and until a $1,000 fine is paid and received at USRA headquarters. Driver will also forfeit all USRA
points (national and track) accumulated up to, and including, the event at which the sabotage occurred.
Furthermore, driver will forfeit the privilege to make a claim for a period of one (1) year from the date on
which the sabotage occurred.
16.18 Driver may claim a maximum of three (3) times during the calendar year.
16.19 After making an accepted claim, driver must finish in the top four (4) of a main event and reinstate
his/her license. Cost is $25 for reinstatement of license. Driver will not be eligible to make another claim
unless license is reinstated.
16.20 Cost for replacement of a lost license is $25.
16.21 Driver must compete in a minimum of three (3) consecutive events prior to the event at which he/she
makes a claim.
16.22 The USRA reserves the right to disallow any claim at their discretion.
16.23 Drivers utilizing a provisional starting position in the main event are not allowed to make a claim in that
event.
16.24 At their discretion, officials reserve the option to claim the cylinder heads and intake manifold, shock or
carburetor of any racecar.
16.25 Drivers will be eligible to make a claim during the first event of the season. After one event, driver must
have raced in previous events before Rule 19.21 applies.
16.26 Disqualification shall not affect a legal claim. Claimed parts will be removed and transferred prior to any
penalties being assessed. All involved claimed parts and related parts are subject to technical inspection
and any illegal parts are subject to all fines and penalties but do not void the claim.