bikrman2

While building my cage I had some questions about how I'm building it. My harness bar is one piece as opposed to 2 piece which in turn means that my diagnoal bar is 2 pieces as opposed to one piece. People said that wouldn't pass tech. My rear lower bar for the "x" in my door bars goes to a base plate in the body with a tube that connects to the main hoop. "Also wrong". Well I did some research and found that NO place in the Pro-Am rule book are any of these things outlined specifically. I'm attaching the roll cage regulations copy and pasted directly from the book. Please let me know what you think.
2.3 ROLL CAGES
Roll cages are required.
2.3.1 BASIC DESIGN CONSIDERATIONS
A. The basic purpose of the roll cage is to protect the occupant if the car
turns over, runs into an obstacle, or is struck by another car. It shall be
designed to withstand compression forces from the weight of the car
coming down on the rollover structure and to take fore/aft and lateral
loads resulting from the car skidding along on its rollover structure.
B. Forward braces and portions of the main hoop subject to contact by the
occupant’s helmet (as seated normally and restrained by
seatbelt/shoulder harness) shall be padded with non-resilient material.
Ethafoam® or Ensolite®, or other similar material with a minimum
thickness of one-half (1/2) inch and conforming to SFI spec 45.1 is
required Formula Drift Professional Drifting
2010 Pro-Am Supplemental Rules and Regulations

2.3.2 General Construction
All roll cages must be based on a single Main Hoop of one (1) continuous
length of tubing with smooth continuous bends and no evidence of crimping
or wall failure. The radius of bends in the roll cage hoop (measured at
centerline of tubing) shall not be less than three (3) times the diameter of the
tubing.
Welding shall conform to American Welding Society D1.1:2002, Structural
Welding Code, Steel Chapter 10, Tubular Structures. Whenever D1.1 refers
to “the Engineer” this shall be interpreted to be the owner of the vehicle.
Welds shall be continuous around the entire tubular structure. All welds shall
be visually inspected and shall be acceptable if the following conditions are
satisfied:
1. The weld shall have no cracks.
2. Thorough fusion shall exist between weld metal and base metal.
3. All craters shall be filled to the cross section of the weld.
4. Undercut shall be no more than 0.01 inch deep.
Aluminum bronze or silicon bronze welding technique is permitted, but
extreme care shall be used in preparation of parts before bronze welding and
in the design of the attaching joints.
No portion of the cage may permeate the firewall and shall be fully contained
within the occupant’s compartment.
The main components of the cage must be made of the same material, size
and thickness of tubing.
2.3.3 Roll Cage Material
Seamless SAE 1020 or 1025, etc. mild steel tubing (DOM) is the preferred
material for Roll Cage construction. Please contact FORMULA DRIFT for
approval if any alloy material will be used. An approved supplier MUST
construct alloy steel cages. ERW tubing is not permitted.
2.3.4 Tubing Size
Roll Cage tubing must conform to the table below and is determined by the
vehicle weight as raced without fuel and driver. The minus tolerance for wall
thickness should not be less than .010" below the nominal thickness.
Vehicle Weight Alloy or DOM
O.D. x wall thickness
(inches)
Up to 3500 lbs 1.500 x .095
Vehicles weighing over 3500 lbs. must petition FORMULA D for approval of the
roll cage prior to entering an EVENT. Formula Drift Professional Drifting
2010 Pro-Am Supplemental Rules and Regulations

2.3.5 Inspection Hole
An inspection hole at least 3/16 inch diameter, but no greater than 1/4 inch
diameter, shall be drilled in a non-critical area of all tubes to facilitate
verification of wall thickness.
2.3.6 Main Hoop:
The main roll hoop (behind the driver) shall extend the full width of the
driver/passenger compartment and shall be as near the roof as possible with
a maximum of 4 bends, totaling 180 degrees ± 10degrees.
The roll cage Main Hoop should start from the floor of the car, and, in the
case of tube frame construction, be attached to the chassis tubes by means
of gussets or sheet metal webs with support tubes beneath the joints to
distribute the loads. It is recommended that gussets be used.
The Main Hoop shall incorporate a diagonal lateral brace to prevent lateral
distortion of the hoop. Any number of additional reinforcing bars is permitted
within the structure of the cage.
A section of tubing equal to the roll bar shall be installed horizontally from the
main hoop to the diagonal brace behind the drivers seat. This tube shall be
no higher than shoulder height and continue from the diagonal to the
passenger side main hoop upright
2.3.7 Front/Side Hoops:
The front hoops, side hoops, or down tubes shall begin at the floor.
Several configurations are allowed:
Side Hoop Configuration: Side Hoops connect directly from the floor of
the occupant’s compartment and continue, in one piece, to connect to the
Main Hoop. If Side Hoops are used, they are to be connected together by
a single horizontal tube across the top of the windshield with a maximum
of 4 bends totaling 90 degrees ± 10 degrees.
Front Hoop Configuration: A front hoop connected to the floor on both
sides of the occupant compartment and following the line of the front
pillars in one continuous piece may be used. A front hoop must be
connected at the top by horizontal bars running back to the main hoop on
each side, above the doors with a maximum of 4 bends, totaling 180
degrees ± 10degrees.
HALO Configuration: A top “halo” hoop following the roofline in one
continuous piece from each side of the main hoop along the tops of the
doors and windshield. A HALO must be connected to the floor with
forward “down tubes” following the line of the front pillars with a maximum
of 4 bends, totaling 180 degrees ± 10degrees and a maximum of 2 bends
allowed on the down tubes. Formula Drift Professional Drifting
2010 Pro-Am Supplemental Rules and Regulations

The front, side or down hoops may extend through the dash pad, including
the forward part of the door panel if it is an extension of the dash panel.
One (1) “Knee” bar is recommended in a horizontal plane between forward
cage braces in the dash area for all configurations.
2.3.8 Rear Hoop Supports:
The main roll hoop shall have two braces extending to the rear attaching to
the frame or chassis. Braces shall be attached as near as possible to the top
of the main hoop not more than six (6) inches below the top and at an
included angle of at least thirty (30) degrees. No bends are allowed on rear
braces. On cars where the rear window/bulkhead prohibits the installation of
rear braces, the main hoop shall be attached to the body by plates welded to
the cage and bolted to the stock shoulder harness mounting points.
2.3.9 BOLT IN ROLL CAGES
Bolt In roll cages are not allowed.
2.3.10 Supplemental Bracing:
Supplemental bracing is allowed.
2.3.11 Side Protection:
All cars shall have a minimum of two (2) door bars across each front door
opening. The door bars may run parallel, or in the shape of an “X”. If the two
door bars do not intersect as they do when forming an “X”, then a minimum of
two vertical tube sections shall connect the upper and lower door bars.
Teams may also choose to install a second row of double horizontal door
bars that run parallel to the inner bars and extend into the outer door skin,
these are also known as “NASCAR-STYLE” bars. In this configuration, the
outer bars must also have a minimum of two (2) vertical tube sections
connecting the upper and lower bars. The inner door panel and door
internals may be removed. Formula Drift Professional Drifting
2010 Pro-Am Supplemental Rules and Regulations

2.3.12 Mounting Plates:
2.3.12.1 Each mounting plate shall be at least .080” thick
2.3.12.2 Mounting plates must be fully welded to the structure of the vehicle.
2.3.12.3 Each mounting plate shall not be greater than 100 square inches and
shall be no greater than twelve (12) inches or less than two (2)
inches on a side. The mounting plate may be multi-angled but must
not exceed these dimensions in a flat plane.
2.3.12.4 Whenever possible, mounting plates shall extend onto a vertical
section of the structure (such as a rocker box or door pillar).
2.3.12.5 Any number of tubes may attach to a single plate or to each other.
2.4 MOUNTING HARDWARE (BOLTS)
All hardware used in the mounting of seats, or other structural supports shall be SAE
Grade 5 or better with a 5/16" minimum diameter.
2.5 FIRE SUPPRESSION SYSTEM
All cars must be fitted with a minimum two (2) lb. fire-extinguishing bottle mounted in
the driver’s compartment within reach of the driver when he/she is in the normal
seated position. The mounting bracket must be a quick-release type, and must be
mounted so that it can be removed easily for label inspection and verification of full
charge by weighing.
Acceptable extinguishants are Halon 1211, Halon 1301, Underwriters Laboratory
10BC rated Potassium Bicarbonate (Purple K), Underwriters Laboratory 1A10BC
Ammonium Phosphate/Barium Sulfate, or Monnex.


I'll post up some detailed pics of my car asap.

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Jonnie Fraz

Tony went through the harness bar issue on Ziptied. The diagonal may be two pieces like you said. The door bars I am not following what you are saying, I may be able to comment once pics are up.

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Stealth-Custom-Fab.com

bikrman2

Thanks for the help.

If you look close the lower bar actually goes to a baseplate thats welded to a 1/4" thick body plate in the convertible body. it's not in this pic but there's also another tube from the main hoop to that lower door bar

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