From a Hot Rod online article:
13.99
NHRA requires a DOT, SNELL or SFI helmet for any car quicker than 14.00. There are a number of different specs so you should check with your local tech inspector.
For cars that run e.t.’s between 12.00 and 13.99, all of the above requirements apply along with the addition of a driveshaft loop. A new-for-’95 rule exempts cars running 13.00 and slower when equipped with street tires. Since traction is the key to going quick, this places more strain on the driveshaft. To prevent the driveshaft from breaking at the front U-joint area and perhaps coming into the interior of the car, or digging into the track and pole-vaulting the car, NHRA mandates that a steel loop be placed just behind the front U-joint of the driveshaft. A universal driveshaft loop is available from Lakewood that bolts to the floorpan. A rollbar is required in this e.t. bracket only if the car is a convertible.
I run low low 12's and I've never been checked for one in my '06 Magnum. When I get into more serious work I'll be adding one, but for now I'm not that nervous.
