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 Modified 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
ARTICLE 1: BODY
1.1 An aluminum half-windshield may be used on driver’s
side of the front window opening only.
1.2 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.
1.3 A minimum window opening of twelve (12) inches must be
maintained on all four (front, back, left and right)
1.4 Streamlining at top of windshield is not allowed.
Bodies must have standard appearing windshield opening and
corner post must follow standard configuration.
1.5 Original roof line of vehicle (parallel to deck, side
to side) must be maintained with a maximum of five (5)
inches of slope from rear to front. Two (2) inch maximum
roll, turned downward, is permitted along the front edge
of the roof. 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 one (1) inch roof lip is
allowed on the left and right edges of the roof. A maximum
of four (4) inch sides on roof allowed. Aluminum roofs are
permitted but must remain flat and not concaved.
1.6 Sail panels must be solid and be of matching design
with matching styles on both sides of racecar. Sail panels
must extend from back of driver’s seat to within a minimum
of three inches from the spoiler support. Sail panels may
have a maximum outward bow of four (4) inches top to
bottom, maximum bow of three (3) inches front to back and
may be no more than eight (8) inches above the back edge
of deck. Sail panel must be mounted within one inch of the
outer edge of the deck and flush with the outer edge of
roof. Sail Panels, measured from side to side, may not
have more than four inches of variance in material length
when measured from roof line to deck.
1.7 Reverse hood rake is not allowed. Hood must be level
or slope forward toward nose of racecar. Back of hood may
be no more than two (2) inches above decking and sealed
off completely. Lips on the sides of hood are not allowed.
Hood must be flat from side to side (bowed or concave
designs are not allowed).
1.8 Belly pans are not allowed. A belly pan will be
defined as any object or material that alters the airflow
under the racecar. A rock shield may be installed to
protect the oil pan and the bottom of the motor, from the
front cross member no further back than the rear engine
mount (mid-plate/mid-mount) no wider than the radiator
front to back.
1.9 Engine covers/panels in front of the door next to the
engine compartment are permitted but must maintain a
left-to-right gap of six (6) inches from the door. One
side must remain open for inspection of engine on the
1.10 Bodies with excessive damage (as determined by an
official) will not be allowed to compete.
1.11 Overall width of the racecar may not exceed
seventy-eight (78) inches—NO TOLERANCE. Width shall be
measured from the widest points on each side of the
1.12 Deck & Trunk Area:
1.12.1 Rear deck lid and/or trunk area must be covered.
1.12.2 Deck length may be a maximum one hundred twenty
(120) inches from rear of engine.
1.12.3 Deck height may be a maximum thirty-nine (39)
1.12.4 Deck must remain parallel to the frame and the same
width from front to back.
1.12.5 Overall slope of deck may be a maximum eight (8)
inches with a maximum four (4) inches slope from driver’s
seat to rear of deck.
1.13 Door and quarter panel height may be a maximum
thirty-seven (37) inches of total material. Doors and
quarter panels may be mounted a maximum of one (1) inch
above the deck and must match side to side—NO TOLERANCE. A
maximum five (5) inch plastic skirt on bottom of doors and
quarter panels and nose piece is permitted. All body
panels must remain outside of outer frame rails.
1.14 Excluding hood and nosepiece, the top of the body
should extend no further forward than the back of the
engine block. The bottom of the body may extend up to
eight (8) inches forward of the back of the engine block.
1.15.1 Maximum overall nose width is forty-two (42)
1.15.2 Two (2) inch nose fins are permitted along both
sides of the nose.
1.15.3 Nose fins may not pass the leading edge of radiator
or continue past leading edge of hood.
1.15.4 All aluminum of the nose (including the fins) must
be completely inside the outer edges of the bumper.
1.15.5 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.
1.15.6 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.
1.15.7 Aluminum or steel is not allowed outside the
1.15.8 All nose piece components must be a minimum of five
(5) inches above the ground.
1.16.1 All spoilers shall be measured as complete material
height including hinge and all hardware associated with
connecting the spoiler to the decking.
a. Option 1: Five and One-Half (5.5) Inch Spoiler –
includes USMTS/USRA spec engine, 23- degree steel-headed
flat tappet engine, GM CT525 crate engine and open engine
option #4. The maximum rear spoiler height shall be five
and one-half (5.5) inches.
b. Option 2: Six (6) Inch Spoiler – includes USMTS/USRA
concept engine. The maximum rear spoiler height shall be
six (6) inches.
c. Option 3: Seven (7) Inch Spoiler – includes GM 604
crate engine. The maximum rear spoiler height shall be
seven (7) inches.
1.16.2 Rear spoiler may not exceed the width of the rear
deck lid, must be flush to the deck and must extend from
right edge of deck to left edge of deck. Spoiler material
must remain flat.
1.16.3 Rear spoiler must remain separate from sail panels.
1.16.4 A maximum of two (2) center supports and a maximum
of two (2) side supports may be attached to the front of
the rear spoiler (see body diagram for dimensions).
1.16.5 Fins, wings, lips, deflectors or other air spoilers
(except as noted above) are not allowed.
1.16.6 Any fins, wings, lips, deflectors or other
permitted air spoilers must match corresponding part on
opposite side of racecar.
1.17.1 Center of bumpers (front and rear) must be a
minimum sixteen (16) inches and a maximum twenty (20)
inches from ground.
1.17.2 Both front and rear bumpers must be used and may
not have any sharp edges. Any inappropriate bumper may be
disallowed at the discretion of an official. Front bumper
should be mounted from frameend 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-thousandths (.065) inch and must be able to support
the racecar if lifted by a tow vehicle. Top bar must be
directly above bottom bar.
1.17.3 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).
1.17.4 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.
1.17.5 Front bumper may be a maximum width of 44 inches
from outside to outside.
1.18.1 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.
1.18.2 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 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
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
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. Must have a cross bar in halo.
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
3.3 All components must be made of steel and be properly
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). Right front frame rail must be at factory
height and may not be raised.
3.6 Rear of frame may be altered to accept leaf or coil
3.7 Hydraulic, ratchet or electric weight jacks are not
allowed anywhere on the racecar. Aluminum jack bolts are
3.8 Wheelbase must be a minimum of one-hundred eight (108)
inches on both sides (no tolerance).
3.9 Tubular front clips are not allowed.
3.10 Maximum overall width of car (at front or rear) shall
not exceed seventy-eight (78) inches—NO TOLERANCE.
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 one eighth (0.125) inch aluminum, or
six one hundredth (0.06) inch steel, complete floor pan
required. No interior sheet metal can 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.
4.5.1 Must be OEM and remain within original bolt pattern
for type of frame used. Center link must match frame.
Inner and 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 The 600 Power Steering Gear Box is 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.
4.6.1 Factory-manufactured racing seats are mandatory, and
must be acceptable to officials.
4.6.2 Homemade aluminum, plastic or fiberglass seats are
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 Packers, bump-stops, biscuits, chains or any other
material meant to limit suspension travel is not allowed
unless noted below (Exception: Bump stops and/or various
rubber biscuits are permitted in conjunction with the pull
bar, rear limiting chains, lift arm chain, right front
shock or blocks from rear-end housing to chassis).
5.2 Suspension and/or rear end parts must be made of
steel. Aluminum and/or titanium components are strictly
forbidden. Aluminum J-bar brackets (chassis and pinion),
upper A-frame cross shafts and limiter chain brackets are
5.3 Vertically mounted steel limiting chains, with or
without rubber bump stops, may be utilized in the rear of
the race car. Chain may be mounted to floating or bearing
type brackets on the rear end.
5.4 All chassis brackets and/or mounts must be welded or
securely bolted to the chassis. Floating, pivoting and/or
rotating mounts and/or brackets of any sort are strictly
forbidden. Gun-drilled, tubular or hollow bolts or studs
are not allowed anywhere on the racecar.
5.5 Suspension covers are not allowed. Tarps or covers are
not allowed on racecar outside of your pit area.
5.6 Front Suspension:
5.6.1 Front suspension must remain stock type for the type
of frame being used. Steel aftermarket parts may be used
as stock components but must mount in the stock location
and be the same size as the OEM parts. This includes lower
tubular A-frames. If using lower tubular A-frames, they
must match factory specs. All parts must meet OE specs and
match side to side. GM 1978-1988 metric “G” body frames
are permitted to use the Nova lower “A” frames. Bottom
A-frames may not be altered, lightened or moved and must
match side to side.
5.6.2 Steel tube-type upper A-frames are permitted and may
be moved. Steel or aluminum cross shafts are permitted.
5.6.3 Only stock passenger car spindles are permitted.
Fabricated spindles are not allowed.
5.6.4 Front sway bars may be utilized. Front sway bars
must be made of steel and may be attached to the bottom
A-frame using steel heim joints (must be solid,
5.6.5 Coil-over springs are not allowed on the front.
5.6.6 Front chains are permitted but must remain loose at
5.7 Rear Suspension:
5.7.1 All rear suspension radius rods must be of a fixed
solid steel design.
5.7.2 Only two (2) radius rods per side are permitted. One
additional rod per side for brake floater only is allowed.
5.7.3 Only one (1) single unit birdcage per side is
permitted. Birdcage must spin freely forward and backward.
Radius rods must mount to birdcage or solid on rear end
housing. If one radius rod is on a bird cage then all rods
must be on birdcages. One additional floated
birdcage-style bracket and radius rod is permitted per
side to accommodate floated brake system only.
5.7.4 Springs and /or shocks may be mounted to birdcage or
lower radius rod or solid on rear end housing. If mounted
on housing, it may be no more than seven (7) inches from
center of axle tube and mounted solid.
5.7.5 Only one (1) mechanical traction device is
permitted. Only one (1) pull bar or one lift arm is
5.7.6 Pull bar is defined as a continuous assembly that is
connected to the top of the rear end and extends forward
to a solid mounting point located on the chassis. The
mounting location at both the front and rear of the pull
bar may be adjustable but must remain constant during
competition (cannot be adjustable from the cockpit). A
lift arm is defined as a solid steel triangulated bar that
is connected at the top and bottom of the rear end housing
and extends forward where it is connected to a shock or
shockspring coil-over combination and a limiting chain
(with or without a biscuit for cushion). One stabilizer
bar is permitted.
5.7.7 Steel coil-over eliminators and/or steel-aluminum
coil-over kits are permitted on the rear only, but must
conform to shock and spring rules.
5.7.8 Rear panhard bars are permitted, but must be made of
steel and may be attached by using a minimum three-quarter
(0.75) inch i.d. steel heim joint.
5.8.1 Any shock may be confiscated by a USRA official at
any time and sent in to be disassembled for inspection. If
found legal, shock will be returned.
5.8.2 Only one shock per wheel is permitted. (Exception:
Fifth shock may be mounted horizontally directly over pull
bar or vertically on front of lift arm). Shocks must be
mounted vertically and rear shocks may be no more than
twenty-five (25) degrees from vertical. Dummy shocks in
relation to functioning shock absorbers are not allowed
(i.e. no dummy shocks to replace slider).
5.8.3 All shocks must be made of steel (magnet must
stick). Aluminum heims on shocks are not allowed (steel
5.8.4 Only conventional-type (closed on one end) shock
absorbers are permitted. Only single-shaft shocks are
5.8.5 Air shocks and/or canister shocks are not allowed.
5.8.6 Inerter shocks, J-damper shocks, active mass damper
shocks and/or through-rod-designed shocks are not allowed.
5.8.7 Bump stops, spring rubbers or any other limiting
devices are not allowed on any suspension component.
(Exception: Bump stops and/or various rubber biscuits are
permitted in conjunction with the pull bar, rear limiting
chains, lift arm chain or blocks from rear-end housing to
chassis, and one (1) rubber bushing on front shock is
allowed no more than one-half (0.5) inch in total rubber
thickness, plastic or steel shims and or cups only.
5.8.8 Electronically-controlled and/or monitored shocks by
any means or methods is strictly forbidden. Cockpit
adjustable shocks are not allowed.
5.8.9 Shock covers are permitted but may cover only front
half of shock and must be mounted directly to shock.
5.8.10 Shocks shall be subject to claim, as outlined in
Claim Procedures (Article 16).
5.9.1 One spring per wheel is permitted. One additional
spring is permitted in the center of the car pertaining to
the pull bar or lift arm.
5.9.2 All coil springs must be at least four and one-half
(4.5) inches outside diameter (except pull bar and lift
5.9.3 Springs must be made of steel.
5.9.4 Torsion bars in the rear are not allowed.
5.9.5 Stacked, tapered and/or welded springs are not
5.9.6 Progressive springs are not allowed (except on pull
bar or lift arm).
5.9.7 Spring wire diameter and coil spread must remain
consistent from one end to the other.
5.9.8 Only conventional spring mounting devices are
permitted. Widgets, trick and/or spring-altering mounting
devices are not allowed.
ARTICLE 6: ELECTRICAL SYSTEM
6.1.1 Must be securely mounted inside frame rails and
covered. If mounted outside of frame rail, a nerf bar
(minimum one and one-quarter (1.25) outside diameter by
ninety-three one hundredths (.093) thickness tubing) must
be installed around battery box for protection.
6.1.2 One (1) 12-volt or 16-volt battery is permitted. One
(1) additional 9-volt battery is permitted to run digital
6.1.3 Voltage converters are not allowed.
6.1.4 All battery posts must be securely covered.
6.2.1 One (1) unaltered ignition system is
permitted—secondary and/or back-up systems are not
allowed. MSD 6CT #PN6427 is recommended.
6.2.2 Magnetos are not allowed.
6.2.3 Crank-triggered ignitions are permitted only on
racecars utilizing a GM CT525 crate engine—must utilize
MSD LS Series #PN6014CT set to the GM recommended preset.
6.2.4 One (1) coil only is permitted.
6.2.5 Kill switch within easy reach of the driver is
required. The switch must be clearly marked “OFF” and
6.2.6 Except for memory recall tachometer, electronic
monitoring computer devices capable of storing and/or
transmitting information are not allowed.
6.2.7 Ignition boxes shall be subject to claim, as
outlined in Claim Procedures (Article 16).
6.2.8 Must utilize a maximum RPM rev-limiter for the
following engine combinations:
• 375 cubic-inch displacement engines or larger is 7,800.
• 374 cubic-inch displacement engines or smaller is 8,400.
• USMTS/USRA Concept Engine is 7,800.
• CT525 Crate Engine is 7,000.
• GM 604 Crate Engine is 6,800.
Any racecar utilizing Engine Option #1 and using a maximum
RPM rev-limiter of 7,200 may utilize a six (6) inch
spoiler. Any driver caught cheating this rule will be
fined $1,000 and never be allowed to utilize a six (6)
inch spoiler in future events. RPM rev-limiter may not be
within reach of the driver while in cockpit and must be
easily accessible to officials at any time. Any driver
caught altering the RPM rev-limiter or ignition system in
any way to defeat the RPM rev-limiter rule shall receive a
thirty (30) day suspension, loss of all points for the
night and a $1,000 fine for the first offense. Second
offense shall be one (1) year suspension, loss of all
points for the season and a $2,000 fine.
6.2.9 Wiring elements must be accessible for technical
inspection. Any racecar advancing spots and missing will
be subject to disqualification.
6.2.10 Cameras pointing to any moving and/or suspension
parts are not allowed.
ARTICLE 7: FUEL SYSTEM
7.1.1 Must be automotive gasoline or alcohol only.
Additives of any kind are not allowed. E85 ethanol or
racing fuel is permitted. Penalty for illegal fuel is loss
of points, cash and awards earned for that event.
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.
Oxygenated fuel is not allowed.
7.2 Electric fuel pumps are not allowed.
7.3.1 One (1) two-barrel, four-barrel or Predator
carburetor properly installed is permitted.
7.3.2 Must be naturally aspirated.
7.3.3 Fuel injection is not allowed.
7.3.4 An adapter with gasket is permitted. Adapter and
gasket combined may be no more than two and onequarter
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
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.
7.4.5 Limited to a maximum capacity of thirty-two (32)
7.4.6 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.
ARTICLE 8: TIRES & WHEELS
8.1.1 Must be fifteen (15) inches in diameter and eight
(8) inches in width.
8.1.2 Stickers are not required.
8.1.3 Must be reinforced steel only. Added ballast to
wheels is not allowed.
8.1.4 A steel or aluminum bead lock may be used on the
right front and right rear wheels only, and may be mounted
on the outside of the wheel so long as it does not add
over three-quarters (0.75) of an inch 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
(5 fastener type recommended). Inner mud plugs are
permitted. All mud covers must display car number on at
least one side.
8.1.7 Wide five wheel adaptors are not allowed.
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 (see Rule 1.11).
8.1.9 Aluminum or steel lug nuts are permitted.
8.2.1 The only tire permitted is the American Racer G60-15
KK704 (Short, Tall or X-Tall). Tires should durometer 50
or harder after 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 All sidewall markings must remain visible always.
Buffing or removing of the compound designations is not
8.2.5 Adding ballast to the inside of the tire is not
8.3 Tire Testing Procedures:
8.3.1 Random lab testing will be conducted at the
convenience of the USRA. Three (3) samples will be taken
with at least three (3) slivers of tire per sample
container. All three containers will be sealed, labeled
and numbered in presence of driver and/or team member and
at least one USRA official. One sample will atomically be
selected to be sent directly to the lab for testing, one
sample will be given to the team to dispute in event of an
issue and one will be kept by USRA. If problems arise, the
race teams’ sample will be sent to the original lab for
comparison to the benchmark. If second sample confirms the
issue, immediate action will be taken as outlined in
Section 2.16.4 of the USRA General Rules, Regulations &
Procedures. Second offenses may be met with up to a
lifetime ban. If the first and second samples vary in
results, the third sample will be sent to the lab for
analysis. Majority (2 out of 3) wins. In addition to
penalties and fines, the competitor will be responsible
for all costs related to tire testing from their racecar
at that event.
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 Rule 2.16.4 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
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. Vented
rotors are required on front and rear wheels.
9.3 Electronic brake actuators are not allowed.
9.4 Calipers and/or pads may not be lightened and must be
OEM. Brake pads may not be altered.
9.5 Steel or aluminum single-piston OEM-type calipers are
permitted. Piston diameter must be the same on all
9.6 Rotors must be steel and may not be lightened,
scalloped or drilled but may be slotted. Rotors may be
re-drilled for different bolt patterns or larger studs.
9.7 Front-to-rear brake bias is permitted (no left to
right). Anything prohibiting the right front brake to
function is not allowed.
9.8 Brake shut-offs are not allowed.
9.9 Brake lines must be visible.
9.10 Must maintain minimum OEM dimensions for hubs,
rotors, pads and calipers, and the same side to side.
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) inch 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 Drive shafts must be painted white.
10.3 Aluminum drive shafts are not allowed. Steel or
carbon fiber drive shafts only (carbon fiber may have
ARTICLE 11: TRANSMISSION
11.1 OEM automatic, three-, four- and five-speed
production-type transmissions are permitted. Approved
aftermarket transmissions are permitted.
11.2 “In and out” boxes are not allowed.
11.3 Must all be clutch-operated.
11.4 Approved aftermarket transmissions are Bert, Brinn,
Falcon, RaceGator and Mitchell Machine Bullet Tranny with
11.5 Clutch must be inside of bell housing for OEM
production-type transmissions (except as noted in Rule
11.6 Clutch-type transmissions must be equipped with an
explosion-proof steel bell housing. Aluminum must be SFI-approved
(Note: GM bell housing is not SFI approved).
11.7 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-eighth
(0.125) inch. Alternatively, automatic transmissions may
utilize an SFI-certified aftermarket guard. All flex
plates must be SFIcertified.
11.8 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
ARTICLE 12: REAR-END
12.1 Any passenger car or truck type is permitted.
Aluminum is not allowed except lowering blocks, axle cap
and drive plate.
12.2 Quick change rear-ends are permitted: Steel tubes
only; ten (10) inch ring gear only; pinion and carrier
bearings must be tapered; titanium is not allowed;
wide-five wheel patterns are not allowed; aluminum spools
are permitted. Magnesium will be permitted until such date
that the cost increases, at which time only magnesium
rear-ends purchased prior to that date will be permitted
and must have original serial number.
12.3 Cambered rear-ends are not allowed. One-piece drive
12.4 Traction devices are not allowed (includes Gold
Track, True Track or similar type components).
12.5 Hub and/or drive flange assembly may not be oversized
and entire hub assembly must match both in material and
dimensions from side to side. Maximum drive flange
diameter is seven (7) inches across, maximum thickness is
one half (0.5) inch.
ARTICLE 13: ENGINE
13.1 General Engine Rules: Unless otherwise noted, the
following general engine rules apply to all engine
13.1.1 Engine type shall determine the overall weight of
the racecar (see Rule 14.3), spoiler height (see Rule
1.12.1) and RPM limits of the rev-limiters (see Rule
13.1.2 Must be able to be used in conventional passenger
car without alteration. Motor mounts may not be removed or
altered. Castings (includes block, heads and intake) and
fittings may not be changed. Machine work on outside of
engine, or on front or rear of camshaft, is not allowed.
If utilizing lightened blocks (removal of material from
inside and/or outside), an additional twenty-five (25)
pounds of weight must be added in front of the mid-plate.
13.1.3 “Dry sump” systems are not allowed. “Wet sump” oil
system only. Internal or external oil pumps are permitted;
however, single pickup must remain in pan with a maximum
one (1) pickup and one (1) return line. External remote
oil tanks (dry sump tanks) are not allowed. Oil coolers
and remote filters are permitted.
13.1.4 Modification of cooling system is permitted.
Radiators and oil coolers may not protrude above interior.
13.1.5 Any American make may be used. 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
13.1.6 Offset must be within two (2) inches of centerline
of front cross member.
13.1.7 Must be a minimum of eleven (11) inches from ground
to front center of crankshaft.
13.1.8 Steel blocks only –aluminum and/or titanium are not
13.1.9 Overflow tubes must be directed toward the ground
and inside the frame rails.
13.1.10 Radiator must be mounted in front of engine.
13.1.11 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. Mufflers
may be required at track's discretion.
13.1.12 Roller cams are permitted, unless otherwise noted.
13.1.13 Intake manifolds must be made of cast iron or cast
aluminum. External modifications to cast aluminum intakes
are not allowed. Internal modifications are permitted.
13.1.14 Tri-Y headers are permitted, but cannot contain
13.1.15 Stud girdles and shaft rockers are permitted.
13.1.16 Engine components must be of matching
manufacturers (i.e. Chevy for Chevy).
13.1.17 Heads may be angle milled, but valve angle must
remain within one (1) degree of original manufactured
13.1.18 Engine components must be of matching
manufacturers (i.e. Chevy for Chevy).
13.1.19 Oil drain back and cooling lines are permitted.
13.2 BRODIX Spec Head Rules: Unless otherwise noted, the
following BRODIX spec head rules apply to both Engine
Option #1 and Engine Option #2 below.
13.2.1 Approved product numbers for the BRODIX aluminum
spec head are SPCH (Chevrolet), SPFO (Ford) and SPMO (Mopar)
for USMTS/USRA. Call 479-394-1075 or visit brodix.com for
13.2.2 Removing, relocating, grinding, polishing or
defacing of any cast letters and/or numbers is strictly
13.2.3 Valve guides must retain original angle and spacing
as manufactured. Valve guides may not be tapered, thinned
or shortened whatsoever. Minimum valve stem diameter must
be five-sixteenths (.310) inch.
13.2.4 Absolutely no welding or adding material of any
13.2.5 Absolutely no enlarging, relocating or other
altering of any bolt hole, dowel hole or threaded hole,
except to spot face bolt holes after angle milling.
13.2.6 Heli coils are permitted for repairs.
13.2.7 Absolutely no grinding or polishing of any kind
anywhere on the casting, except for pushrod clearance.
Factory CNC chamber may not be altered in any way.
13.2.8 Internally-repaired BRODIX aluminum spec head must
be recertified by BRODIX.
13.2.9 BRODIX aluminum spec head checking fixtures may be
used by tech officials to check specifications and
13.3 Engine Option #1: USMTS/USRA Spec Engine (2,450
pounds, 5½-inch spoiler):
13.3.1 Roller cam or flat tappet cam is permitted.
13.3.2 All other BRODIX Spec Head Rules apply (see Rule
13.3.3 Flat tappet 23-degree steel-headed engine and GM
CT525 crate engine (see 14.5 for complete details) will
also fall under this option.
13.4 Engine Option #2: USMTS/USRA Concept Engine (2,400
pounds, 6-inch spoiler):
13.4.1 Any cast iron block is permitted. Unnecessary
machine work inside or outside of block is not allowed.
Lightening, coating, painting or any other work to inside
of intake manifolds, heads and/or block lifter galley is
13.4.2 Maximum 14:1 compression is permitted.
13.4.3 Steel oil pan only is permitted. Wet sump system
only is permitted. Cast iron oil pump must be in stock
location. Oil pan must have inspection hole.
13.4.4 Unaltered aluminum intake is permitted. Must be
seven and one-quarter (7.25) inches from bottom of intake
to base of carburetor, including spacer and gaskets.
Intake may be port matched, maximum one (1) inch from
13.4.5 Stud mount rocker arms or shaft rocker arms are
permitted. Maximum 1:6 ratio. Stud girdle is permitted.
13.4.6 Steel valves and valve spring retainers/locks only.
Hollow stem and/or titanium valves are not allowed.
13.4.7 Cast iron flat tappet cam with stock diameter
journal, stock firing order, in stock location, with stock
diameter. Cast iron lifters only. Mushroom lifters are not
13.4.8 Timing chain only is permitted. Gear or belt drive
is not allowed.
13.4.9 Stock diameter “Babbitt” cam bearing only is
13.4.10 7,800 maximum RPM chip is required.
13.4.11 Steel crankshaft only is permitted. Gun-drilled
mains are not allowed. Undercutting of counterweights is
13.4.12 Steel balancer only is permitted.
13.4.13 Tri-Y headers are not allowed.
13.4.14 Aluminum valve covers are permitted.
13.4.15 All other BRODIX Spec Head Rules apply (see Rule
13.4.16 Titanium parts are not allowed with this engine
13.5 Engine Option #3: GM Crate Engine (604 = 2,400
pounds, CT525 = 2,450 pounds)
13.5.1 The properly-sealed GM 604 crate engine may be used
and may utilize a seven (7) inch spoiler.
13.5.2 The properly-sealed GM CT525 crate engine may be
used and may utilize a five and one-half (5.5) inch
13.6 Engine Option #4: Open Engine (2,500 pounds, 5½-inch
13.6.1 Any engine not listed in the above options will be
included in this engine option.
13.6.2 Must have twenty-five (25) pounds of weight in
front of mid-plate if utilizing aluminum heads.
ARTICLE 14: WEIGHT
14.1 The overall weight of the racecar shall be measured
after an event with the driver in the cockpit, wearing
complete racing apparel. A “burn off” allowance may be
offered at specific events where the number of laps will
exceed normal conditions. This allowance, if any, shall be
determined by USRA officials before the event begins.
14.2 All racecars must display weight at which it will
compete on left side windshield post. 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.
14.3 Overall Weight:
14.3.1 If utilizing Engine Option #1 (USMTS/USRA Spec
Engine, 23-degree steel-headed flat tappet or GM CT525
Crate Engine (see 14.5 for details), the overall weight of
the racecar must be a minimum of two thousand four hundred
fifty (2,450) pounds.
14.3.2 If utilizing Engine Option #2 (USMTS/USRA Concept
Engine), the overall weight of the racecar must be a
minimum of two thousand four hundred (2,400) pounds.
14.3.3 If utilizing Engine Option #3 (Crate Engine) the
overall weight of the race car must be a minimum of two
thousand four hundred (2,400) pounds for the GM 604 Crate
Engine or two thousand four hundred fifty (2,450) pounds
for the CT525 Crate Engine.
14.3.4 If utilizing Engine Option #4 (Open Engine), the
overall weight of the racecar must be a minimum of two
thousand five hundred (2,500) pounds, and must have a
minimum of twenty five (25) pounds of weight in front of
14.4 If utilizing the CT525 Crate Engine, racecar must
have a minimum of twenty five (25) pounds of weight
mounted in front of the mid-plate.
14.5 If utilizing lightened blocks (removal of material
from inside and/or outside), an additional twenty-five
(25) pounds of weight must be added in front of the
mid-plate (see Rule 13.1).
14.6.1 May not be mounted in cockpit, or outside of body
or hood area or on any rotating parts.
14.6.2 Must be securely mounted, painted white and clearly
marked with the car number.
14.6.3 Must be attached with at least two (2) one-half
(0.5) inch bolts per a maximum one hundred (100) pounds of
ballast. Any ballast weighing twenty-five (25) pounds or
less may be mounted with a single one-half (0.5) inch
14.6.4 May not be attached to rear bumper.
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, always, 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
15.5 Helmet must accompany driver and racecar at time of
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. Shoulder harness must be
mounted to main cage and not the tail section of car.
15.9 Metal to metal buckles are required on shoulder and
15.10 Shoulder harness must be mounted securely to the
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 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 or securely bolted to the roll cage. All
bars around the driver must have approved roll bar
padding. Approved racing arm restraints are recommended.
Window net mounts are highly recommended to be securely
welded or bolted to the inside of the main roll cage on
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. All drivers, licensed
or not, are subject to being claimed.
16.2 Any driver in the “A” Main is eligible to claim the
shocks or ignition box of another racecar in the “A” Main.
16.3 Claims must be made within five (5) minutes of the
completion of the “A” Main. Claimed items must be removed
at the racetrack and within one (1) hour after claimed
driver accepts the claim.
16.4 Immediately following the conclusion of the “A” Main,
without returning to his/her pit location, driver making
claim must drive racecar, under its own power, directly to
the designated claim area. Claiming driver shall select
from eligible racecars in the “A” Main, 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 on his/her claim card. If multiple
drivers declare an intention to claim, the driver
finishing farthest back in the “A” Main will select first.
16.5 Claiming driver must present cash to official
overseeing the claim area at the time the driver declares
intention to claim. The cash price of the claim shall be
$200 each for shocks or $250 for ignition boxes. Drivers
claiming shocks may claim one (1) or more shocks during a
16.6 Driver is permitted one (1) claim per event,
regardless of the outcome of that claim.
16.7 Only drivers 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.
16.8 Only a driver may claim, and only the claimed driver
may agree to accept or refuse the claim. The first
statement of acceptance or rejection of the claim by the
claimed driver is binding.
16.9 Any driver refusing to accept a claim will forfeit
all cash winnings and contingency awards for that event.
Any driver 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.
Furthermore, driver will forfeit the privilege to make a
claim for a period of one (1) year from the date on which
the claim was refused.
16.10 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 by the
USRA. 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.
16.11 Driver must compete in three (3) consecutive USRA
events prior to executing a claim. Driver may claim a
maximum of three (3) times during the calendar year.
16.12 The USRA reserves the right to disallow any claim at
16.13 At their discretion, officials reserve the option to
claim the shocks or ignition box of any racecar. Officials
may exchange ignition boxes at any time.
16.14 Disqualification shall not affect a legal claim.
Claimed parts will be removed and transferred prior to any
penalties being assessed.