2011 rule book - general regs.
4:10 ROLL BAR
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 or be within 1 inch of the roof/headliner in the area above the driver's helmet, and be at least as wide as the driver's shoulders or within 1 inch of the driver's door. Roll bar must be adequately supported or crossbraced 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. Crossbar and rear braces must be welded to main hoop. 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 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 chromoly 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. Beginning June 1, 2011, all cars running 9.99 (*6.39) or quicker, SFI Spec 45.1 mandatory.
An 8 point would be helpful in stiffening the chassis more with the extra 2 bars behind the seats running from the cross bar/main hoop junction to the frame connectors.