When do I need a roll cage?

dsaxman — Wed, 20 Sep 2006 22:11:16 GMT

NHRA tracks:

When do I need a roll bar or roll cage, and what should it look like?
A roll bar is required in any convertible running 13.99 seconds or quicker in the quarter mile, and in other cars beginning at 11.99. The roll bar is accepted in vehicles running as quick as 10.00 second e.t., provided the stock firewall and floorboard is intact, other than for installation of wheel tubs. The rollbar must be constructed of minimum 1 ¾ inch o.d. x .118 inch wall mild steel tubing, or 1 ¾ x .083 chrome moly tubing, and must conform to the following diagram:

If the floor and/or firewall has been modified, then a full roll cage is required beginning at a 10.99 e.t. A full roll cage is required in any vehicle running 9.99 seconds or quicker, and any vehicle running 135 mph or faster (regardless of e.t.). The roll cage must be constructed of minimum 1 5/8 o.d.x .118 mild steel tubing, or 1 5/8 x .083 chrome moly tubing, and must conform to the following diagram:

The roll cage of any vehicle running 9.99 or quicker, or 135 mph or faster, must also be certified by NHRA every 3 years, and have a serialized sticker affixed prior to participation.

NHRA info taken from: http://www.nhra.com/contacts/tech_faq.html

IHRA tracks:
ROLL BARS{reprint from IHRA Rulebook}
Mandatory in all cars running 11.49 or quicker, or per class requirements. All roll bars must be within 6 inches of the rear or side of the driver's head, extend in height at least 3 inches above the driver's helmet with driver in normal driving position, and be at least as wide as the driver's shoulders or within 1 inch of the driver's door. Rollbar must be adequately supported or cross-braced to prevent forward or lateral collapse. Rear braces must be of the same diameter and wall thickness as the roll bar and intersect with the roll bar at a point not more than 5 inches from the top of the roll bar. Sidebar must be included on driver's side and must pass the driver at a point midway between the shoulder and elbow. Swing-out sidebar permitted. All roll bars must have in their construction a cross bar for seat bracing and as the shoulder- harness attachment point; cross bar must be installed no more than 4 inches below, and not above, the driver's shoulders or to side bar. All vehicles with OEM frame (i.e. pickup truck where body bolts to framerails) must have roll bar welded or bolted to frame. Installation of frame connectors on unibody cars does not constitute a frame; therefore, it is not necessary to have the roll bar attached to the frame. Unibody cars with stock floor and firewall (wheeltubs permitted) may attach roll bar with 6-inch x 6-inch x .125-inch steel plates on top and bottom of floor bolted together with at least four 3/8-inch bolts and nuts, or weld main hoop to rocker sill area with .125-inch reinforcing plates, with plates welded completely. All 4130 chrome moly tube welding must be done by approved TIG heliarc process; mild steel welding must be done by approved MIG wire feed or approved TIG heliarc process. Welding must be free of slag and porosity. Any grinding of welds prohibited. Roll bar must be padded anywhere driver's helmet may contact it while in driving position. Adequate padding must have minimum 1/4-inch compression or meet SFI Spec 45.1.

ROLL CAGE{reprint} Mandatory in all cars running quicker than 10.99 seconds or faster than 135 mph, or per class requirements. Cars with unaltered firewall, floor and body (from firewall rearward, wheeltubs permitted) running between 10.00 and 10.99, roll bar permitted in place of roll cage, or per Class Requirements. Cars with altered firewall, floor faster than 11.49 must have rollcage and window net. All cage structures must be designed in an attempt to protect the driver from any angle, 360 degrees. All 4130 chrome-moly tube welding must be done by approved TIG heliarc process; mild steel tube welding must be approved MIG wire feed or TIG heliarc process. Welding must be free of slag and porosity. Any grinding of welds prohibited. Additionally, roll cage must be padded anywhere the driver's helmet may contact it while in the driving position. With driver in driving position, helmet must be in front of main hoop. If helmet is behind or under main hoop, additional tubing, same size and thickness as roll cage, must be added to protect driver. Main hoop may be laid back or forward, but driver must be encapsulated within the required roll cage components. On unibody cars with stock floor and firewall (wheel tubs permitted), the roll cage may be bolted or welded to the floor/rocker box via 6- inch x 6-inch x .125-inch steel plates Unless attaching to OEM floor or frame, the minimum requirements for a frame member to which a roll cage member is attached are 1 5/8- inch x .118-inch MS or .083-inch CM round and/or 2-inch x 2-inch x .058 MS or CM rectangular. All cage structures must have in their construction a cross bar for seat bracing and as the shoulder-harness attachment point; cross bar must be installed no more than 4 inches below, and not above, the driver's shoulders, or to side bar. All required rear braces must be installed at a minimum angle of 30 degrees from vertical and must be welded in. Side bar must pass the driver at a point midway between the shoulder and elbow. Unless an OEM framerail is located below and outside of driver's legs, a rocker or sill bar, minimum 1 5/8-inch x .083 CM or .118 MS or 2-inch x 2-inch x .058-inch CM or MS rectangular, is mandatory in any car with a modified floor or rocker box within the roll-cage uprights (excluding 6 square feet of transmission maintenance opening). Rocker bar must be installed below and outside of driver's legs and must tie into the main hoop, the forward hoop, frame, frame extension, or side diagonal. Rocker bar may not tie into swing-out side bar support. If rocker bar ties into side diagonal more than 5 inches (edge to edge) from forward roll-cage support or main hoop, a 1 5/8-inch x .083 CM or .118 MS brace/gusset is mandatory between the diagonal and forward roll-cage support or main hoop.

Above info taken from: http://www.maritimedragracing.com/id5.htm

Roll Bar / Roll Cage:
Swing out bars are permitted on OEM full bodied entries running 8.50 and slower. The must be designed as follows: 1 5/8 diameter x .083 cm or .118 ms connected with a minimum of 3/8 bolts or pins affixed in double shear. Clevis or sliding sleeve connections permitted. All male brackets must be a minimum of 1/8 inch with corresponding female bracket being 1/4 inch. Sliding sleeves must have a minimum of 2 inch engagement at the connection.

10.00 to 11.49

Rollcage: A rollcage is mandatory on all convertibles running 10.99 or quicker ¼ or 6.99 or quicker 1/8 mile. T-top vehicles follow convertible guidelines.

11.50 to 13.49 section

Rollbar / Rollcage: A minimum of a 6 point roll bar is mandatory all convertibles running 11.00 to 13.49 ¼ mile and 8.25 or quicker 1/8 mile.

A roll cage is mandatory on any entry that exceeds 135 mph.

Above info taken from: http://www.ihra.com/competition/2006revisions.htm

The first cage/bar graphic above is also used for reference on the IHRA rules per the maritimegragracing link provided above.

Track

When do I need a roll cage?