A .500 light is perfect so that if you red light you can tell by how much. A .400 reaction time means that you were a tenth of a second before the green light.
Beginning at the K&N Filters Winternationals, the opening round of the 2003 POWERade Drag Racing Series, NHRA will implement two significant changes on the starting line for the NHRA national events.
First, the numerical value of a driver's reaction time will be modified at each of the 23 national events. The modification simplifies the process of understanding a driver's reaction time to activation of the green lights on the Christmas Tree. Previously, a perfect reaction time for professional, and some sportsman drivers, was a .400. For the remaining sportsman competitors a .500-light was considered a perfect reaction time. Under the new changes, the timing system will be modified to display a perfect reaction time as .000 for all categories. This change only applies to the 23 national events that make up the $50 million NHRA POWERade Drag Racing Series.
On a pro Christmas Tree, a .399 light, or anything lower, would be considered an early start, activating the red light, which would result in a disqualification. Under the new system, a .399 will now be displayed as a -.001, a.398 will be a -.002, and so on. Anything from a perfect reaction time of .000 and above will be a legal start. The new timing system in no way affects any driver, vehicle set-up, or any other significant aspect of the competition on the drag strip.
Also, as previously reported, NHRA will implement the use of LED amber lights on the Christmas Tree starting system, replacing the traditional yet damage-prone incandescent lights.
"The biggest advantage is that the vibration, especially that caused by the Top Fuel and Funny Car classes, won't cause the LED bulbs to burn out like it will an incandescent," said NHRA's Graham Light. "Amber bulb failures, especially during full Tree countdowns in the Sportsman classes, lead to re-runs and other problems. We are trying to avoid that problem as well as step up our technology.
"We tested the new bulbs without problem during preseason testing in Tucson," added Light, "but racers attending the Winternationals and subsequent events are advised that the LED lights illuminate quicker, by about three-hundredths of a second, than the incandescent lights."