Hoosier Racing Tire:
*** Tires will be checked for soaking and by durometer for
hardness before each car goes on the track for qualifying or any
2350# - Open Motor
2300# - Steel Block/Aluminum Head - Spec Motor Only (8" spoiler
allowed, 12" sides)
2250# - CT525 Motor (8" spoiler allowed)
2250# - All Steel Motor or Crate Motor (8" spoiler allowed,
* 1# per lap burnoff + 5 lbs. in B-Mains and Feature
UPDATED RULES FOR 2018
WILL BE POSTED SHORTLY... PLEASE KEEP CHECKING BACK!
1. The rules and/or regulations set forth herein do not express
or imply warranty of safety, from publication of, or, compliance
with these rules and/or regulations. They are intended as a guide
for the conduct of the Spring Nationals and are in no way a guarantee
against injury to participants.
2. These rules and/or regulations will apply to all Spring Nationals
sanctioned racing events.
3. Spring Nationals officials have full authority over said sanctioned
racing events. In the event of any dispute the Race Directors
decision will be final.
4. All racecars are subject to be inspected by the Spring Nationals
Technical Director at any time during the event.
5. The Spring Nationals officials reserve the right to alter
or amend these rules and/or regulations in the interest of fair
A. Nosepiece and roof must match body style of car.
B. All cars must have a minimum of one inch (1”) and
a maximum of two (2”) inches of roll at top of fenders,
doors, and quarter panels. A sharp edge will not be permitted.
Body roll must go from sides over interior, not interior over
C. Floorboards and firewall must cover the driver’s area
and be constructed to provide maximum safety.
D. Driver’s seat must remain in the same general area
as the general design of the car.
E. Windshield screen or bars are mandatory.
F. Legible numbers, at least eighteen inches (18”) high
are required on each side of the car and roof.
G. No fins or raised lips of any kind are permitted anywhere
along the entire length of the car.
H. Bodyline must be a smooth even line from front to rear.
I. No “slope noses” or “wedge cars”
permitted. Noses must be stock appearing, subject to Series
J. No “belly pans” or any type of enclosure on
bottom of car is permitted. Skid plate to protect oil pan is
K. No wings or tunnels of any kind are permitted underneath
the body or chassis of the car. A maximum of one (1) stone deflector,
for rear mounted oil pumps, oil filters, and for the main oil
tank will be permitted. The deflector may be made of steel,
aluminum, or heavy gauge wire. The cover may only be mounted
near the unit it is designed to protect with a maximum size
of 18”x 18” and mounted only from the upper right
frame rail to the lower right frame rail.
L. All non-approved bodies will be assessed a fifty pound (50#)
minimum weight penalty.
M. No panels of any kind under the rear deck running from the
front to the rear of the car.
N. Any air cleaner scoops used must be positioned in front
of or around the air cleaner and cannot exceed one (1”)
inch in height above any part of the air cleaner. The scoop
cannot be designed with fins or raised edges to direct airflow.
The scoop cannot extend behind the rear of the air cleaner and
must have a maximum width of seventeen inches (17”) at
the rear, with a maximum of ten inches (10”) width at
the front and cannot have more than one inch (1”) opening
from the in height at the front.
O. No adjustable shocks, hydraulic or pneumatic weight jacks,
trackers, MSD boxes or similar adjustable components of any
kind are permitted inside the cockpit of the car. Taping over
of any adjuster is not permitted. The offending component must
be removed from the cockpit.
A. All stock nosepieces must be approved by a Spring Nationals
B. Nosepieces must be made of molded type material.
C. Two piece noses must be fastened together in center. No
spacers to gain width are permitted.
D. The nosepiece must be mounted so as not to alter its original
E. No material can be removed from the nosepiece. No cutting
from bottom, top or sides is permitted.
F. No adding to the bottom of the nosepiece in the front achieve
lower ground clearance is permitted.
G. A stock nosepiece can extend a maximum of forty-eight inches
(48") from the center of the front hub to the farthest
point extending forward.
H. Front fender flairs must be made of plastic and cannot alter
the original shape of the nosepiece. The front fender flairs
cannot extend beyond the front tire more than one inch (1")
in width with wheels pointed straight.
I. Front fender flairs must have collapsible support.
J. The nose piece must have a headlight decal package attached.
One warning will be permitted and then the car must run contrasting
color tape in the shape of a headlight.
ROOF AND ROOF SUPPORTS
A. The roof length size must be a minimum of forty-four inches
(44") to a
maximum of fifty-four inches (54").
B. The roof width size must be a minimum of forty-eight inches
(48") to a
maximum of fifty-two inches (52").
C. Roof must be stock appearing and mounted level.
D. Roof height must be between forty-five inches (45”)
and forty-eight (48”) from the ground.
E. The roof must be mounted parallel to body and near center
of the car.
F. A maximum one and one half inch (1.5”) roll, tuned
downward, is permitted along the front edge of the roof. A maximum
one-inch (1”) roll turned downward is permitted along
the rear edge of the roof. (Roll permitted to help strengthen
G. No flat or odd shaped roofs permitted.
H. All roof side panels must extend to the edge of the body.
Maximum Roof side panel window size – seventeen inches
(17”) at the top, forty-three inches (43”) maximum
at the bottom. The window area may be covered with clear Lexan
or transparent material. Both roof support openings must be
covered or both must be left open. Decals will be permitted
but must meet the dimensions in the drawing and must be approved
by the Technical Inspector. Maximum two inch (2”) bow
in either direction in rear roof side panels is permitted.
I. Front posts must be flat and if uniform width from top to
bottom – four inch (4”) maximum width.
J. Any sun shields, four inch (4”) maximum, must be able
to hinge for easy exiting of car.
FRONT FENDERS AND HOOD
A. Must be level and flat from left to right side of car.
B. Fenders not permitted to gain height from rear to front
C. No part of fender or hood can be outside of the bodyline.
D. The front fender can be a maximum of thirty six inches in
height. Height is measured vertically from the ground to the
top of the fender behind the front tires.
A. Door to door cannot exceed seventy-six inches in width at
the top of the doors.
B. Door to door cannot exceed eighty two inches in width at
the bottom in the center of the car.
C. Doors cannot exceed thirty-six inches in height measured
from the ground.
D. At no point can the door sides break in towards the center
of the car between the top and bottom measurements.
E. The minimum ground clearance permitted is three inches.
A. No offset quarter panels permitted. Must be equally tapered
towards the center of the car.
B. Tire clearance from body must be a minimum of tow inches
(2”). No wheel skirts permitted.
C. At no point can quarter panel sides break in towards center
of the car.
A. No aluminum frames permitted in construction of car.
B. Minimum 103” wheelbase.
C. Rectangle or Square Tubing:
The frame of all cars must be constructed of two inch (2”)
by two-inch (2”) minimum Rectangular or square tubing
with a minimum of eight inch (8”) circumference and a
minimum of eighty-three thousands inch (.083”) wall thickness.
D. Tube Frame: The frame of all cars must be constructed of
a minimum of one and three-quarter (1¾”) round
tubing and must have a wall thickness of eighty-three thousands
inch (.083”) wall thickness minimum.
E. If rear bumper is stubbed, it may only extend a maximum
of eight inches (8”) beyond frame. Any stubbed rear bumpers
that extend eight inches (8”) or more beyond frame must
be rounded and directed towards the front of the car.
F. It is recommended that all cars be equipped with a tow hook
G. All battery supports must be braced in two axis - two horizontal
and one vertical.
A. Cars must have a suitable steel roll cage in drivers’
compartment including headrest.
B. Side roll bars are mandatory and must extend into the door
C. A minimum of three (3) bars must be used on the left side
of the car. Each bar must be a minimum of one and one-half inch
(1½’) in diameter with a minimum thickness of ninety-five
thousands inch (.065”).
D. Roll cage must be welded to the frame.
E. Roll cage must be above the drivers’ helmet.
F. No “fin-shaped” or “foil-shaped”
add-ons permitted on any part of the roll cage. The entire roll
cage must be constructed of round tubing only.
A. Interior is permitted to be dropped to the middle of the
car a maximum of three inches (3”) below the top of doors
and a minimum of twelve inches (12”) below the roll cage.
B. Interior must gradually taper up to the quarter panel height
and be level for thirty-two inches (32”) from the rear
of the quarter panel.
C. Interior must be fastened flush at the top of the door and
quarter panels and may taper gradually towards the center if
the car not creating a “lip effect”.
D. Interior must run in a straight line from behind the drivers’
seat to the rear spoiler.
E. If interior is flat through the car, it must maintain a
twelve-inch (12”) clearance from roll cage for easy exciting
from either side of the car.
F. All cars with interior panels must at NO point in the car
be over three inches (3”) in height. The portion of the
panel running beside the driver must taper to zero or end in
line with the steering wheel.
G. If interior is dropped at firewall, that portion of the
firewall must be filled for safety reasons.
A. Rear spoiler must be manufactured of material of adequate
strength such as Lexan or Aluminum.
B. Rear spoiler material maximum eight-inch (8”) height
measured for deck to tip of material. Maximum seventy-two inch
C. Rear spoiler is not permitted to be suspended above the
deck to create a “wing effect.”
D. Rear spoiler must begin where quarter panels end. No extended
E. Maximum of three (3) rear spoiler supports. Option of two
(2) additional one inch (1”) aluminum braces.
F. Spoiler supports cannot be mounted wider than the top of
the quarter panel.
A. An approved fuel cell (32 gallon maximum) must be securely
mounted in the trunk area of the car inside a 20-gauge metal
box supported by two 1/8 x 2" steel straps.
B. A firewall must be installed between the fuel tank and drivers’
A. Gasoline or Alcohol only. Nitrous gases or other nitrate
additives are not permitted.
TRANSMISSION, CLUTCH AND REAR END
A. Any transmission with working reverse and working forward
gears is permitted.
B. Manual transmission must be equipped with an operational
C. Automatic transmissions are permitted.
D. The transmission must be mounted to the rear of the engine
and lead to one drive shaft.
E. No “live-axle” rear-ends are permitted.
F. No independent rear suspensions are permitted.
G. All rear-ends using a cable to lock-in the rear-end must
have the cable mounted outside the cockpit area and not in reach
of the driver.
A. All drive shafts must be a minimum of two inches in diameter.
All drive shafts must be painted silver or white.
B. Only one drive shaft is permitted.
C. The driveshaft must be protected with a secure driveshaft
hoop or sling.
A. Steel, aluminum, carbon-fiber or plastic wheels are allowed.
B. Wheels must be mounted with lug nuts: no knock-off mounting
devices are allowed.
C. Maximum wheel width is fourteen inches (14”).
D. Maximum width outside of front tires is ninety inches (90”).
E. Maximum width outside of rear tires is eighty-eight inches
A. Must be equipped with sufficient braking system.
SHOCKS AND SPRINGS
A) Shocks must be constructed
of aluminum or steel. Canister shocks are permitted.
1. The only external connection allowed to the shock is a single
hose to a single remote canister with the option of a compression
adjuster in the canister.
2. Compression adjuster and/or canister cannot be mounted within
the reach of the driver.
B) No cross connected shocks
1. The only external connection allowed to the damper is a single
hose to a single remote canister with the option of a compression
adjuster in the canister.
2. Compression adjuster and/or canister cannot be mounted within
the reach of the driver.
C) No 'Rod-Through' designs are
1. 'Rod-Through' shocks are defined as those shock absorbers
in which the piston rod protrudes from both ends of the shock
D) No Inerters are allowed.
1. No rotating parts inside the damper.
2. No inerter style dampers, either mechanical or hydraulic,
or other type of primarily acceleration sensitive damping devices
E) No electrical adjusted or
active dampers are allowed. No electrical wires, transmitting
or receiving components will be allowed to be attached internally
or externally to the dampers or mounted inside of any components
or dampers. No portion of the race car including and not limited
to - shocks and spring components or chassis components may
have the ability to communicate transfer/transmit/receive any
type of digital or analog data or any language and or adjust
or monitor in any way whatsoever including but not limited to
a variation of a wireless remote device/phone/computer/table/iPad
or a mechanical remote device.
F) Springs must be made of steel.
Torsion bars are not allowed in the rear.
G) Coil springs must be steel.
Leaf springs may be composite or steel.
H) Shock Locations:
1. Only one shock per wheel is permitted at the left front,
right front right rear corners.
2. Left rear must have one shock behind the axle tube and may
have one traction (dummy) shock on the front side or top of
axle tube. Must mount vertically to the birdcage or clamp bracket.
3. One 5th Coil Shock permitted.
4. One 90/10 optional shock may be mounted above lift arm on
upper lift arm plates.
I) Drop Chain (limiting chain)
is permitted. Must mount vertically between frame and a clamp
J) Bump Stops and/or bump springs
K) Suspension covers are not
allowed. Rear covers on racecar are not allowed outside of your
pit area. Spring and/or shock covers are permitted, but must
be fastened directly to the spring or shock.
L) A Swing Arm and/or Z Link
suspension is permitted as long as the Top and Bottom solid
links are mounted on hiems and run in the opposite directions
of the bird cage. The Shock on a Swing Arm or Z Link rear suspension
may mount to the bird cage or the bottom radius rod.
A) Suspension and/or rear end
parts can be made of steel or aluminum. Aluminum mounting brackets
B) Frame and/or suspension mounts
must be welded or bolted solid to the frame and not move. ie-Floating,
sliding, pivoting and/or rotating mounts and/or brackets of
any sort are not allowed.
C) Bolted components must match
the correct bolt size with the hole (for instance no 3/8 bolts
in a ½ inch hole will be deemed illegal) and be torqued
to a min. of 40 foot pounds per inch.
D) Rear Suspension Mounts:
1. Single sheer mounts must be ¼" minimum steel
and/or ½" minimum aluminum.
2. Double sheer mounts must be 1/8" minimum steel and/or
¼" minimum aluminum.
3. Sheer mounts must use minimum 5/8" rod ends with minimum
½" grade 8 bolts only.
4. Double sheer mount must be no wider than 4 inches with a
minimum ½" inch grade 8 bolt with steel or aluminum
E) Only one (1) mechanical traction
device is permitted. Only one (1) pull bar or one (1) lift arm
is permitted. No other options are allowed. Covers of any sort
in any relation to the lift arm or pull bar are not allowed.
F) Lift Arm and Pull Bar:
1. Floating, pivoting and/or rotating mounts and/or brackets
of any sort (connected to and/or associated with the pull bar
or lift arm) are not allowed.
2. Lift arm is defined as a steel or aluminum triangulated car
that is connected at the top and bottom of the rear end housing,
extending forward where it is connected to a shock, shock-spring
coil-over combination and a limiting chain. One stabilizer bar
is permitted to locate the front of the lift arm from left to
right in the car.
3. 6th coil or braking spring assemblies are permitted, must
be in front of the 5th coil shock.
4. 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
G) Radius Rods:
1. All rear suspension radius rods must be of a fixed length.
No hydraulic cylinders, torsion bars, bump rods, spring rods,
slider rods or shock-type radius rods are permitted.
2. Radius rods must be minimum of 1" diameter OD. Rods
can be round, square, or hex shaped. Rods must be minimum of
.095 steel or .120 aluminum in tubing thickness.
3. Heim joints must be a minimum 5/8, and a maximum ¾"
steel heim. No rubber bushings.
4. ONLY - Two (2) radius rods per slide.
a. Radius rods must be spaced on the frame a minimum of 6".
b. Radius rods must be spaced on the birdcage a minimum of 6"
and a maximum of 12".
c. Measurements will be made from center of each radius rod
1. Birdcages may consist of multiple barrels but must bolt or
weld together to work as a single barrel birdcage.
2. Limited one (1) birdcage per side.
3. Shock(s) and radius rods must mount to the birdcage.
4. Floating, pivoting and/or rotating mounts and/or brackets
of any sort are not allowed. All brackets or mounts attached
to the birdcage must be bolted or welded solid.
REMOTE CONTROL SUSPENSION DEVICES
A) NO "in-cockpit driver
controlled" suspension devices permitted. NO weight jacks
of any kind permitted. (This includes fifth [5th] coils etc.)
ANY driver using "in-cockpit driver controlled" suspension
devices or weight jacks WILL BE DISQUALIFIED FROM COMPETITION.
A. Mufflers are MANDATORY. Only variance of this rule will
be where not required by host track.
B. Exhaust is not permitted to be directed towards ground.
Exhaust must be parallel to the ground.
TRACTION CONTROL DEVICES
A. All Traction Control Devices are strictly prohibited during
any form or portion of a Spring Nationals sanctioned event,
race or practice/test session.
B. All traction control devices whether electronically controlled
in the ignition system, wheel sensors or any means of measuring
ground speed to control wheel spin are strictly prohibited.
All devices not mentioned in the above that are found to control
wheel spin, timing or fuel delivery control will be considered
C. At NO time during the season and beyond will there be any
type of ping control devices, dial a chip controls, timing controls
or any modifications to the ignition control boxes, distributors,
or any other part of the Ignition System. This includes any
add on component or components inside or outside the cockpit
of any competitors racecar. There shall be NO driver controlled
wheel spin, timing or fuel delivery control devices in the cockpit
area of any racecar.
D. A competitor found with any of the above mentioned will
lose the complete device permanently and will lose all points
earned to that point in the season. NOTE: A competitor may be
asked for his electronic ignition at any time by the Tech. Director
to be sent for testing and inspection. Failure to hand over
the electronic ignition will result in the holding of any purse
A. Any driver or crew member found altering the racing surface
will be disqualified.
B. NO two-way radios.
C. NO "in-cockpit driver controlled" electronic devices
of any kind permitted.
D. NO computer controlled devices of any kind permitted.
E. NO rearview mirrors of any kind permitted.
F. RACECEIVERS ARE MANDATORY!!!
G. Spring Nationals officials reserve the right to change and/or
alter rules and procedures at any time. ALL OFFICIAL
DECISIONS ARE FINAL!