SECTION 6: NHRA PRO MOD DRAG RACING SERIES, FRAME: 4, ROLL CAGE (Page 6)
Chassis must meet SFI Spec 25.1. Chassis must be recertified yearly by NHRA and have serialized sticker affixed to roll cage before participation. See General Regulations 4:4, 4:11, 10:6.
Prior to 2022 chassis reinspection, all cars must implement an the under seat pan as per the SFI 25.1 specification: “The under-seat portion of the driver’s outer floor must contain .090” minimum sheet 4130 (annealed or normalized) steel pan, either above or in lieu of the under-seat diagonals. If the steel sheet pan is in lieu of under-seat diagonals, the pan must be fully welded around its perimeter. The purpose of the sheet steel is to be a foundation when a minimum of ¾” of SFI 45.2 foam under the driver’s buttocks and thighs is required. Either rub tubes, or the bottom of both the driver side rocker bar (#7A) and driver side inner frame rail (#2A) within 6” of the pan must extend at least ½” below the lowest point of the seat pan. If rub tubes are employed for this purpose, they must be minimum 1” x .058” 4130 or DOCOL R8 welded to the driver side rocker bar (#7A) and the driver side inner frame rail (#2A) within the length of the pan.”
A panel of .032-inch aluminum, .024-inch steel, or carbon fiber must be installed on the inside portion of the roll cage anywhere the driver’s legs can come into contact with the cage (chassis tubing). Panels must be installed in the front and lower portion of the driver’s-side X brace. Panels must attach to the interior side of the tubing. Panels must not be attached to rocker bar (7A), Windshield/Roof bar (12A) or Main Hoop (10). Optional padding may be attached to the panels.