Quote:
Originally Posted by ironworks
Define Pro-touring events? I think Silver state has the biggest mandate. The single day non competitive events should not require anything I believe.
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SIVER STATE CHALLENGE
ROLL BAR SPECIFICATIONS Roll Bar: A Roll Bar is mandatory in the Grand Sport Division, and recommended in Grand Touring
and Touring.
Basic Design Considerations: The basic purpose of the roll bar/roll cage is to protect the driver in case the vehicle rolls over. This purpose should not be forgotten.
A.
B. C.
The top of the roll bar shall not be below the top of the driver’s helmet in a closed car and a minimum of two (2) inches above the driver’s helmet in an open car when the driver is in the normal driving position. It shall not be more than six (6) inches behind the driver.
The two vertical members forming the side of the hoop shall not be less than fifteen (15) inches apart, inside dimensions, at their attachment point to the uppermost chassis member.
An inspection hole of at least 3/16-inch diameter must be drilled in a non-critical area of the roll bar member to facilitate verification of wall thickness. This should be at least three inches from any weld or bend.
D. Cars with factory built or factory reinforced roll structures may be allowed in the Grand Sport Division. They will be evaluated on a per car basis. The decision of the Event Director will be final.
Material: The roll bar hoop and all braces must be of seamless DOM (Drawn over Mandrel) mild steel tubing 1010 thru 1025 or alloy tube steel SAE 4130 chrome moly. Proof of alloy, leave unpainted. All NEW roll bars must meet or exceed this requirement.
A. The size of the tubing to be used must be determined on the basis of the weight of the car. (pg. 16)
Fabrication: The main vertical hoop must be one continuous length of tubing with smooth mandrel bends and no evidence of crimping or wall failure. No bend radius will be smaller than 3 times the tube diameter.
A. All welding must be of the highest quality with full penetration. All attachments points must be welded 360 degrees around the tube. Welding must conform to American Welding Society codes.
B. It is recommended that gussets should be welded at the junction of any tubes. Bracing: it is recommended that braces be of the same size tubing as used for the roll bar itself.
A. B.
C.
All roll bars must be braced in a for or aft direction with the brace attached within six (6) inches of the top of the hoop, and at an angle of at least thirty (30) degrees from vertical.
It is required that a diagonal brace be used to triangulate the main hoop, and it is highly recommended that this brace be attached at the top on the driver’s side and attached to the bottom on the “passenger” side. See Exhibit A
A headrest is required if not part of the seat.
Revised 1/2010 - Page 15 -
6.
7.
8.
9. 10.
11.
Mounting Plates: Roll bars and braces must be attached to the frame of the car whenever possible. Mounting plates must be used for this purpose. When the main hoop is attached to sheet metal, such as a floor attaching point for unibody cars, the mount plate must be at least 36 square inches (6” x 6” plate) on both sides of the sheet-metal or that provided by the manufacturer. If possible the plate should extend up the vertical wall.
A. A minimum of double-nutted 3/8 inch grade 5 bolts for self-locking or welded nuts shall be used to bolt to the car. No bolts are needed if the bar is welded to the car’s frame. Plates welded to the floor must be at least as thick as the bars tube.
B. In the case of cars with unitized or frame less construction, mounting plates must be used to secure the roll bar structure to the floor of the car. The important considerations is that the load be distributed over as large an area as possible. Plates bolted to the floor must be at least 3/16 inch thick and be placed on both sides of the sheet metal. A back-up plate of equal size and thickness must be used on the opposite side of the panel with the plates through- bolted together.
Removable Roll Bars: Removable roll bars and their braces must be very carefully designed and constructed to be at least as strong as a permanent installation. If one tube fits inside another to facilitate removal, the removable portion must bottom on the permanent mounting, and the mounting hardware used to secure each joint must be grade five (5) or better. It is recommended that the telescope section be at least eight (8) inches in length.
Installations on Cars of Space Frame or Frame less Design: It is important that the structures be attached to cars in such a way as to spread the loads over a wide area. It is not sufficient to simply attach the roll bar to a single tube or junction of tubes. The roll bar must be designed in such a way as to be an extension of the frame. Considerable care must be used to add as necessary to the frame structure itself in such a way as to properly distribute the loads. It is not true that a roll bar can only be as strong as and single tube of the frame.
On cars of frame less construction, consideration should be given to using a vertical roll bar hoop of 360 degrees completely around the inside of the car, and attaches with suitable mounting plates. This type of roll bar then becomes a substitute for the frame.
Other Designs: Deviations from the above will be considered. Roll Bar Padding: Roll bar padding must be used to protect the Driver/Navigator in all areas of
possible contact.
Minimum Tubing Sizing: The size of the tubing to be used shall be determined on the basis of the weight of the car.
Under 2200 lbs. 2200 to 3000 lbs.
3000 to 4000 lbs Over 4000 lbs
DOM 1.50” O.D. X .095 wall mild DOM 1.50” O.D. X .095 wall alloy
DOM 1.75” O.D. X .120 wall mild DOM 1.75” O.D. X .095 wall alloy
DOM 1.75” O.D. X .120 wall mild or alloy DOM 2.00” O.D. X .120 wall mild or alloy
Revised 1/2010 - Page 16 -
XI.
ROLL CAGE SPECIFICATIONS
4
4
3.
4.
5.
1. 2.
Roll Cage Division Requirements: A roll Cage is mandatory in the Super Sport and Unlimited Divisions.
Super Sport & Unlimited Division Requirements:
A. The cage may be removable or may be permanently welded, or any combination thereof, providing that all aspects of the cage meet these rules.
B. A NASCAR style roll cage is highly recommended.
C. Material, Fabrication, Bracing and Installation specifications are the same as the specifications for a Roll Bar. See Section X, pages 15 & 16 for detailed information.
D. None of the tubing may show any signs of crimping or wall failure. All bends must be Mandrel type
E. One continuous length of roll bar tubing shall be used as the main hoop. The main hoop must consist of not more than four (4) bends maximum, totaling one hundred eighty (180) degrees +/- ten (10) degrees.
F. At least one (1) diagonal brace must be used in the same plane as the main hoop. One end of the diagonal brace shall attach to the corner or horizontal part, of the main hoop above the drivers' head, within twelve (12) inches of the drivers'-side corner.
G. The forward hoops extend from the main hoop (in a forward direction) to the floor by following the roof and the "A" pillar of the car. There must be a bar connecting the two (2) forward hoops at the top of the windshield mounted as close to the roof as possible.
H. The main hoop must have two (2) braces extending to the rear. The braces shall be attached as near as possible to the top of the main hoop, and no more than six (6) inches below the top.
I. At least two (2) door bars on the driver and passenger sides must be used. The top door bar crossing height between the shoulder and elbow may be angular or horizontal. The second door bar should be horizontal.
J. The roll cage shall be mounted to the floor of the car in six, seven, or eight points. All cage attachment points must be mounted to plates.
K. Welded mounting plates must be at least as thick as the tube wall.
L. The attaching points of a bolt-in cage to the body must use reinforcing plates to sandwich the body. At least three bolts are required for each bolt-in plate and the plate must be at least 3/16 inch thick. All hardware must be SAE grade 5 or better with 3/8 inch diameter minimum. All nuts must be held by a locking system, such as lock washer, or jam-nuts.
M. All welding must be of the highest quality with full penetration. All attachment points must be welded 360 degrees around the tube. Welding must conform to American Welding Society codes.
N. All required bars must be made of the same material and meet with at least the minimum specifications for size and thickness.
O. All roll cage surfaces that may come in contact with the driver must be padded with high- density padding such as Ethafoam or Ensolite.
Specification: See Roll Bar Specification for the roll cage fabrication specification. Main Hoop and Braces: The main hoop and support braces should be of the same size.
Minimum Tubing Sizing: The size of the tubing to be used shall be determined on the basis of the weight of the car.( pg. 16 )
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
LOL
Very timely for me to find it now, as I will need to do a cage for my race rod eventually, and would have been really tempted to fall into the "moly" trap. I was doing it to save weight, but had assumed the savings would be more than thy really are. After reading this thread, and since my main rails are mild steel, it seems logical now to do the cage in mild steel.
Hybrid Mode
