Here you go. This is stright off of the NHRA web site.
A helmet is required for the driver of any car or truck running 13.99 seconds or quicker in the quarter mile, and for the rider of any motorcycle. Most drivers can use a helmet meeting SNELL M85, M90, M95, SA85, SA90, SA95 or K98 specifications. Professional category and some alcohol burning vehicles require an SA rated helmet. It is important to note that the helmet rating must be designated on a tag INSIDE the helmet, or sewn to one of the helmet straps. The designation stenciled on the exterior of the helmet is insufficient for NHRA technical inspection. Also, some tracks require a helmet on ALL drivers, so check in advance.
Rule : 10.5 HELMET
Drivers in all 13.99 (*8.59) or quicker cars, and Dune buggy type vehicles running 14.00 (*8.60) seconds or slower must wear a helmet meeting SNELL 85, 90 or SFI 31.1, 31.2, 41.1 or 41.2 Specs or BSI BS 6658-85 type A (including all amendments) Specs. Driver's in supercharged front-engine open-bodied cars must wear a helmet meeting SNELL SA95, SA90 or SFI 31.1 or 31.2 Specs or BSI BS 6658-85 type A (including all amendments) Specs. See General Regulations 10.7.
<font size=-1>[ This Message was edited by: Freddie on 5/19/06 7:31am ]</font>