The Basics
Riverina Drag Racers Association
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glossary racing terms
A
drag race is an acceleration contest from a standing start between two
vehicles over a measured distance. The accepted standard for that distance
is either a quarter-mile (1,320 feet) or an eighth-mile (660 feet). A drag
racing event is a series of such two-vehicle, tournament-style eliminations.
The losing driver in each race is eliminated, and the winning drivers
progress until one driver remains.
These
contests are started by means of an electronic device commonly called a
Christmas Tree because of its multicolored starting lights. On each side of
the Tree are seven lights: two small amber lights at the top of the fixture,
followed in descending order by three larger LED lights, a green bulb, and a
red bulb.
Two
light beams cross the starting-line area and connect to trackside
photocells, which are wired to the Christmas Tree and electronic timers in
the control tower. When the front tires of a vehicle break the first light
beam, called the prestage beam, the pre-stage light on the Christmas Tree
indicates that the racer is approximately seven inches from the starting
line.
When
the racer rolls forward into the stage beam, the front tires are positioned
exactly on the starting line and the stage bulb is lit on the Tree, which
indicates that the vehicle is ready to race. When both vehicles are fully
staged, the starter will activate the Tree, and each driver will focus on
the three large amber lights on his or her side of the Tree.
Depending
on the type of racing, all three large amber lights will flash
simultaneously, followed four-tenths of a second later by the green light
(called a Pro Tree), or the three bulbs will flash consecutively five-tenths
of a second apart, followed five-tenths later by the green light (called a
Sportsman, or full, Tree).
Two
Separate performances are monitored for each run: elapsed time and speed.
Upon leaving the staging beams, each vehicle activates an elapsed-time
clock, which is stopped when that vehicle reaches the finish line. The
start-to-finish clocking is the vehicle's elapsed time (e.t.), which serves
to measure performance. Speed is measured in a 66-foot "speed trap" that
ends at the finish line. Each lane is timed independently.
The
first vehicle across the finish line wins, unless, in applicable categories,
it runs quicker than its dial-in or index. A racer also may be disqualified
for leaving the starting line too soon, leaving the lane boundary (either by
crossing the centerline, touching the guardwall or guardrail, or striking a
track fixture such as the photocells), failing to stage, or failing a
post-run inspection (in NHRA class racing, vehicles usually are weighed and
their fuel checked after each run, and a complete engine teardown is done
after an event victory).
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