SUPER STOCK & STOCK
Indexes are set by NHRA, but in two of the categories, Super Stock and Stock, a racer may choose his own index as long as the new number is not slower than NHRA’s index. During qualifying rounds, racers in these classes try to figure out the best index for the prevailing track and weather conditions.
Sometimes in these classes, it appears that one driver gets a head-start but it’s not a head-start, really. To make a better race, NHRA has determined a time that each of the classes of cars in Super Stock and Stock should run. For example, a 1978 Chevy truck won’t run as quick as a 1965 Mustang but with the indexes the truck can run competitively against the Mustang.
If the truck’s index is 11.50 seconds and the Mustang’s is 9.00, the truck would get a green light 2.50 seconds before the Mustang. The driver who gets the closest to his own index, without going too quick, wins. If the Mustang gets to the finish line in 9.50 seconds and the truck got there in 11.60 seconds, the truck would win because there was only a .10-second difference between his index and his actual time, and there was a .50-second difference for the Mustang.
COMP ELIMINATOR, SUPER COMP, SUPER GAS & SUPER STREET
In these four categories, the NHRA’s established indexes may not be changed. The index for Comp Eliminator depends on the type of engine in the car; the index for Super Comp is 8.90 seconds; Super Gas is 9.90 seconds; and Super Street is 10.90 seconds. Competitors in the Super Comp, Super Gas and Super Street classes do not make qualifying runs, but run time trials in order to become consistent for eliminations. NHRA may adjust the indexes depending on the altitude of the track.
ADDITIONAL NHRA LUCAS OIL DRAG RACING SERIES CLASSES
In the other six classes, racers are competing not only against each other, but also against the clock and themselves. For each of the categories NHRA has established time “indexes” based on the horsepower and weight of the car.
The object is to get as close to your index as possible without going too quick. For example, if the index is 10.10 seconds, 10.00 seconds is too quick. That’s called a “break out” and you lose. You can also lose if the racer in the next lane gets closer to his index than you get to yours.