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When do I need a roll bar or roll cagE?

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: