2009 NHRA rule for full bodied car
Roll Bar 11.49 to 10.00
Main hoop, side door bars, and rear bars:
1 3/4 O.D. x .118 wal thicknes mild steel tubing
1 3/4 O.D. x .083 wal thicknes chromoly tubing
Side to side bar which the seat belt shoulder straps mount to:
1 1/4 O.D. x .118 wal thicknes mild steel tubing
1 1/4 O.D. x .065 wal thicknes chromoly tubing
STD. Roll Cage 9.99 to 8.49
Main hoop, halo, side door bars, and rear bars:
1 5/8 O.D. x .118 wal thicknes mild steel tubing
1 5/8 O.D. x .083 wal thicknes chromoly tubing
When an X configuration is used instead of 1 door bar:
1 1/2 O.D. x .118 wal thicknes mild steel tubing
1 1/2 O.D. x .083 wal thicknes chromoly tubing
Side to side bar which the seat belt shoulder straps mount to:
1 1/4 O.D. x .118 wal thicknes mild steel tubing
1 1/4 O.D. x .065 wal thicknes chromoly tubing