Seat Belts and Harnesses

The most common required certification is SFI 16.1. Generally, when your race sanction says they require an SFI approved belt, this rating will do the job. When certifying for 16.1, SFI applies a load over a body block of 5,750lbs each on the laps and shoulders and over the complete 5 or 6 point assembly. The harness must not break under 6,300lbs for lap and shoulders belts, and 1,500lbs for anti-submarine straps. SFI labels should be placed on the left shoulder belt, left lap belt, and sub strap.

Some off-road sanctions are now requiring or recommending belts with higher breaking strength. This would be SFI 16.5. When certifying for 16.5, SFI applies a load over the body block of 11,000lbs over the complete 5 or 6 point assembly. The harnesses must not break under 7,000lbs for lap, shoulder, and anti-submarine straps. Additional tests are also run, including a roller adjuster micro-slip test and a webbing abrasion test. SFI labels should be placed on each shoulder belt, lap belt, and anti-submarine strap. Re-webbing is not permitted. This rating is mandated by NASCAR Truck Series, NHRA Top Fuel, and Funny Car. NASCAR leads the way in safety research and training so it’s wise to take their recommendation.