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DRAG RACING 101
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 (1320 feet), or an eight mile ( 660 feet ). A drag racing event is a series
of such two car, tournament style eliminations. The losing vehicle in each race is
eliminated, and the winning drivers progress into succeeding rounds of competition. This
series of races continues until one winning driver remains.
These contests are started by means of an electronic device commonly called a
"Christmas Tree" because of its multicolored staging 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 amber bulbs, a green bulb, and a red bulb.
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1. Pre-stage indicator lights: Small amber bulbs warn drivers that they are
approaching the starting line and the staged position. These bulbs are illuminated when
the front tires of the car interrupt a light beam that crosses the lane.
2. Stage indicator: This signals to the driver that he is on the starting line and ready
to run.
3. Three amber starting system: All three large amber lights flash simultaneously before
the green light comes on for a Pro start. Racers running in handicap-start categories get
a countdown until the green comes on.
4. Green light: Once the green light flashes, the driver is free to make his/her run. Any
time that the green light is shown in a racer's lane indicates that a fair start was
accomplished.
5. Red light When the front wheels of the car leave the starting line before the green
light flashes, or if a driver stages so deep that he/she crosses the starting line , the
red light will shine. It indicates that the driver in that lane is disqualified. |
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Two light beams cross the starting-line area and connect to trackside photocells,
which are wired to the Christmas Tree and the electronic timers in the control tower. When
a cars front tire breaks the first light beam, called the pre-stage beam, the pre-stage
light is illuminated on the christmas tree to indicate to the racer that he or she is
approximately seven inches from the starting line. |
When the racer rolls forward into the stage beam, the front tires are exactly
positioned on the starting line and the stage bulb is lit on the tree, indicating to both
racers and to officials that the car is ready to run. When both cars are fully staged, the
starter will activate the tree and the drivers will turn their attention to
the three large amber lights that dominate the center of the christmas tree.
Depending on the type of racing, the christmas tree either will flash all three large
amber lights simultaneouly, followed four-tenths of second
later by the green light (called a Pro Tree), or will light the three bulbs
consecutively five-tenths of a second apart, followed five-tenths of a second
later by the green light (a full tree).
If a driver and/or his car react too quickly and the car leaves the starting line before
the green light flashes, the red foul light will illuminate, signaling
disqualification.
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Timing methods
Two seperate performances are monitered for each run: the elapsed time and the speed. Upon
leaving the staging beams, each vehicle activates an elapsed time clock which is stopped
when the same vehicle reaches the finish line. The start to finish clocking is the
vehicles elapsed time (E.T.), which serves to measure performance. Speed is measured in a
66-foot "speed trap" that ends at the 1/8 mile mark and the finish line. Each
lane is timed independently. |
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1. Pre-staged beam:A
light-source-to-photocell connection (one per lane) triggers the prestage beam when the
driver is approximately seven inches from the starting line.
2. Stage beam: The beam controls the final staging and timing in each lane. A race cannot
be started until both racers are fully staged.
3. Interval timers:A secondary timing system, with beams located at 60, 330, 660, and 1000
feet, records E.T.s for the racers benefit. A 66-foot speed trap also is set at the
660-foot mark.
4. Speed trap and E.T. time-clock beams:The first of these beams is located at 66 feet
before the finish line and is used to trigger the speed trap clocks. A second beam,
located at the finish line, shuts off both the speed and elapsed time clocks in addition
to triggering a win indicator.TOP |
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E.T. and handicapped racing
This is where 85% of all racers are now and where 100% started out.
Though some racers choose to race vehicles built to certain specifications to fit into a
certain NHRA class (outlined in the NHRA rulebook), an evergrowing number of racers
chooses to race on a local level in categories (or brackets) divided according to elapsed
time , such as 0 to 9.99 seconds, 10.00 to 13.50 seconds, and so on. This form of racing
offers a good starting point for the novice. However, thousands of drag racers enjoy
E.T. racing so much that they have participated for many years.
Anytime two vehicles of different performance potentials race, they can do so evenly with
handicap start. The anticipated elapsed times - referred to as a
"dial-in" - for each vehicle are compared and the slower car receives a head
start equal to the difference. The winner is the first car to the finish
line without exceeding the dial-in.TOP |
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Dial-ins
For example, car A has been timed at 15.98, 16.02 and 15.99 seconds for the quarter-mile,
and the driver decides that a dial-in of 16.00 is appropriate. Meanwhile, the driver of
car B has recorded elapsed times of 13.47, 13.52, and 13.56 on the same track and he has
opted for a dial-in of 13.50. Accordingly, car A will get a 2.5 second head
start over car B when the christmas tree counts down to each cars starting green light.
This puts the emphasis on driver reaction.
Because the lanes are timed independantly and the elapsed time clock does not begin
ticking until the vehicle moves, if both vehicles should run exactly on their dial-ins,
the win will go to the driver who reacted quickest to the starting signal. that reaction
to the starting line signal is called reaction time.TOP |
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Reaction times
Reaction times are measured in thousandths of a second. The reaction time counter begins
when the last yellow flashes on the Christmas Tree and stops when the race
car clears the stage beam. (Although some reaction timers begin counting when the green
light flashes, this is not the case in the majority of starting systems.) A
perfect start - one in which the race car clears the beam at the very instant the green
light flashes - will produce a .400 reaction time on a Pre Tree and a .500
on a full tree (the difference is due to the length of time between the final yellow
light and the green light in the two sequences.) Reaction time also measure the
amount of a red light violation. For example, if a pro Tree car leaves the
starting line with a .390 reaction time (or .490 on a full tree), the driver will have
fouled by .010 of a second.
Technique in staging and starting is one of the most vital skills of a E.T. racer because
a majority of races are won or lost on the starting line.
A driver with a quicker reaction time can overcome an opponent's perfomance
advantage - whether it's in a heads up race or if the opponent runs closer
to his/her dial-in - and record the win. Beacause of this the vehicle may sometimes appear
to have a mathematical advantage in comparative elapsed times but actually lose the race.
This fact makes starting line reflexes extremely important in drag racing. Close
observation and lots of practice pays off.TOP |
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Breakouts and Other
Disqualifications
Should a driver go quicker than their predetermined E.T. dial-in, it's a breakout, and
grounds for disqualification. In the case of both vehicles running under
their dial-ins, the win gos to the driver that runs closest to his/her dial-in. If both
drivers violate their dial-ins by an equal amount, the winner is the driver
who crossed the finish line first, which will also be the driver with the quickest
reaction time at this point.
Other disqualifications include leaving the lane boundry (either by crossing the
centerline, touching the wall or the guardrail or striking a track fixture,
such as photocells.), failure to stage, and failure to pass a post-run inspection (in NHRA
class racing, usually this consists of a check of vehicle weight and fuel
after each run and a complete engine teardown following an event victory).
The NHRA employs a "first or worst" rule for disqualifications. A red light is
considered worse than a breakout; crossing a lane boundary is worse than a
red light, even though it may have occured after the red light; and all technical
disqualifications supersede any on track disqualifications.TOP |
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Who can compete?
Virtually anyone can compete in E.T. drag racing. Drivers are required to have valid state
drivers license or NHRA competition license, and the vehicle must meet
basic saftey criteria (i.e. have good brakes, be equiped with seatbelt and so on). This
applies to most street type vehicles.
Faster, all-out race cars must meet more stringent requirements as in outlined in
the NHRA rulebook.TOP |
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