A. All chassis/frames built after during and/or after the 2005 season should have a manufacturer’s serial number and identification plate visible and welded on the left front side of the roll cage upright. See drawings.
B. Roadster type chassis will not be permitted.
C. The chassis must have a minimum of six (6) mounting points for securely mounting any manufacturer’s seat per the seat and chassis manufacturer’s specifications.
D. Drag links must be made of 4130 steel a minimum of one (1) inch in diameter and a minimum material thickness of .058 inches. Tie Rod and Left Front Radius Rod must be 4130 steel with magnetic steel rod ends. Swaging of the tubing for Tie Rod and Drag Link will not be permitted. The drag links must be tethered to the frame with a minimum of one (1) inch nylon webbing.
E. Hollow and/or drilled bolts, fasteners, and/or heim joints (rod ends) will not be permitted.
F. Titanium front axles, nerf bars and/or rear bumpers will not be permitted. Nerf bars and rear bumpers must be made from magnetic steel and/or stainless steel. Left and Right Nerf bars must attach to the chassis at three points. The bumpers must be a minimum of one (1) inch in diameter and have a minimum material thickness of .065 inches. The nerf bars must not extend past the outside edge of the tires.
G. Only front axles made of magnetic steel will be permitted. Approved axle dimensions are:

a. 2 1/4” diameter x .120” material thickness
b. 2 3/8” diameter x .095” material thickness
c. 2 1/2” diameter x .095” material thickness

H. Approved front axle tether systems are mandatory. The tether mounting must meet the SFI 55.1 specifications which includes two (2) Vectran® HS V-12, or Dynemma 12 tethers attached to the chassis.  Tether systems must include a “kingpin to kingpin” tether that will attach to the axle clamp/band or pass through the loop of wrap style axle tethers.  Tether cables should be installed using the manufacturer’s provided fasteners.  Tether systems of any type must be pre-approved and installed in accordance with the manufacturer’s instructions. 2019 will be the last year “bolt to bolt” radius rod axle tethers will be allowed. January 2020 all axle tether systems must clamp to or wrap around the axle per the manufacturer’s instructions.
I. The front bumper must not extend more than eight (8) inches from the frame and/or the measurement from the center of the front axle to the front of the front bumper must not exceed 23 ½ inches.
J. The top of the roll cage shall have a maximum outside width of 29.5 inches. Bracing that would prevent the driver’s ability to exit through the opening and/or inhibit safety/rescue worker’s ability to extract the driver will not be permitted.
K. The cockpit horizontal middle frame bar will have a maximum outside width of 32 inches.
L. The bottom frame rail will have a maximum outside width of 26 .5 inches.
M. All tubing utilized in the construction and/or fabrication of the main frame must be round in shape. Any other shapes, such as elliptical (oval) tubing will not be permitted.
N. Only steel, carbon fiber or aluminum floor plans will be permitted.
O. The minimum wheelbase will be 83 inches. The maximum wheelbase that will be permitted will be 90 inches.
P. Front anti-roll torsion bar assemblies (sway-bars) will not be permitted.
Q. All cars must have a driveline strap and/or a driveline hoop restraint constructed of a minimum of .065 inch magnetic steel either welded and/or bolted to the chassis. The rear cross member used for mounting the steel driveline hoop must be constructed of .083 inch steel.
R. Wings, bumpers and/or nerf bars must be positively fastened with bolts & nuts, hitch pins and/or roll pins only.  For any car to be pushed off at any time the rear bumper must be in place behind the tail tank.
S. The only chassis and/or frame adjustable device (including adjustable shock absorbers) that may be within the driver’s reach will be one (1) top wing adjuster, for the top-wing slider mechanism. The slider must be one-dimensional and allow forward and rearward movement only.
T. Only conventional and thru-rod style shock absorbers will be permitted.  Beginning January 1, 2015 any new style shock or any shock not in use with the WoO Sprint Series previous to this date must be approved by WoO prior to being placed into competition.  Performance, safety and cost, along with other variables, will factor into the approval process.  It is recommended that the approval process be completed prior to product production.  Approved thru-rod style shocks:

a. Penske – Part # PS-7700T

U. The following frame measurements are minimum dimensions. Only those areas indicated are mandatory and subject to technical inspections. In lieu of the “BUTT” BAR a car’s rear end can be tethered to the rear chassis.  Only ASTM4130 normalized steel or equivalent material may be used in the chassis/frame construction. See drawings:

a. Top Rails 1 ½” x .095”
b. Bottom Rails 1 3/8” x .095” or 1 ½” x .083”
c. Roll Cage Uprights 1 3/8” x .083”
d. Roll Cage Crossmember 1 ½” x .095”
e. Upper Rails 1 3/8” x .083”
f. Rear End Safety “Butt Barr 1” x .083” or 1 ¼ X .065
g. Brace 1 ¼” x .065”

V. All chassis will be required to have additional bars installed to support and decrease the span between the front and rear uprights in the drivers area. The new support bars must be in addition to the front and rear uprights. Any attempts to manipulate the front and rear uprights to conform to these measurements will not be allowed at the discretion of World of Outlaws Series Officials. These additional bars will be minimum 1.375 X .083 ASTM4130 normalized steel or equivalent material as per World of Outlaws current rule 15.5.U. Left and right side support bars may be one of the three designs below. Left and right side support bars do not have to be of the same design. Right side body opening shall remain the same per rule 15.7.J in the World of Outlaws Sprint Car Series Rule Book.  Left and right side support bars may be one of the three options:

a. Support bar may be designed similar to what was known as a “safety bar”. It must be attached to the top rail at a point 15” to 20” from the rear of the front upright. It must attach to the hip rail and have a gusset attached to the rear upright near a point opposite of the rear brace/shock mount bar. The curve must be between 4” and 7” measured from outside of the rear upright tube to the outside of the support bar. See Drawings.
b. Existing chassis with a left side support bar installed (formerly called safety bar) that do not meet the option one specification above, may add a gusset that attaches to the top rail 15” to 20” from the rear of the front upright and angle to the support bar. The existing support bar tubing must meet the minimum as described above (1.375 X .083 ASTM4130 normalized steel or equivalent material). See Drawings.
c. A support bar may be added to the top rail at a point 15” to 20” from the rear of the front upright and to the rear upright near a point of the rear brace / shock mount bar but no higher than 7” above the hip rail. This bar may have a slight curve near the rear upright to accommodate elbow room and ease of fitment. See Drawings.

W. Slip-tubing is not allowed in the chassis construction. Any existing slip-tubing must be replaced or welded. Clamped or bolted slip tube joints will no longer be allowed.
X. Torsion arm stops will be mandatory on both sides of the front torsion bars. The retainer may be of the rod-type with a securing cap or insert with an expanding mandrel and/or any other approved Torsion arm stop design. Torsion arm stops must be installed and used in accordance with the manufacturer’s instructions.  The following torsion bar stops(s) have been approved for competition:

a. Moose Block 1200 Retainer Kit
b. All Star Performance All Star 10730 Retainer
c. Maring Safety Retainer
d. Butlerbuilt Mandrel
e. KKR grove and clip
f. Kaeding Clip
g. DMI – T-REX (Torsion Restraint Express System)
h. Schroeder Part Number: “BARS” (for Schoeder bars with relief in ends)
i. Schroeder Part Number: “RWLAR” (Wedge Lock)

The approved Torsion Arm Stop may be revised from time-to-time with additional approvals and/or other changes to the approved list.
Y. CARBON FIBER:  No carbon fiber parts, excluding torque tubes and brake rotors, will be allowed in the suspension (includes radius rods), steering components, or drive line
Z. All radius rods shall be constructed as a solid piece of round tubing with provision for a rod end on each end. Radius rods must be attached to the chassis and axle attachment points with said rod ends and no other devices between rod ends and attachment points will be allowed. Devices that are designed to change the length of a radius rod in any way while the car is moving will not be allowed. Items such as but not limited to springs, air chambers and/or shock absorbers will not be allowed in any form on radius rods.