Terminologies to Help The Racers

Here are some drag racing terms so you “racers” out there aren’t

left scratching your heads. A little knowledge goes a long, long

way my friends.



Air foil: acts as a stabilizer creating that much needed down
force for better traction and control


Bang the blower: an explosion inside the supercharger caused by a flame from the
combustion process accidentally re-entering the supercharger,
where fuel and air are present. Generally caused by a stuck or
broken intake valve that normally would be closed during the
combustion sequence.


Breakout:Used only in handicap racing, “breakout” refers to a
contestant running quicker than he or she “dialed” his or her
vehicle (predicted how quick it would run). Unless the opponent
commits a more serious foul (e.g., red-lights, crosses the
centerline, or fails a post-race inspection), the driver who
breaks out loses. If both drivers break out, the one who runs
closest to his or her dial is the winner.


Burned Piston: When a cylinder runs lean (too much air in the air
-to-fuel mixture) and excessive heat burns or melts the piston.


Burnout: spinning the rear tires in water to heat and clean them
prior to a run for better traction. A burnout precedes every run.


Christmas Tree: Also called the Tree, it is the noticeable
electronic starting device between the lanes on the starting line.
It displays a calibrated-light countdown for each driver.


Clutch Can: The bell-shaped housing, or bellhousing, used to
encase the clutch and flywheel.


Clutch Lockup: The progression of clutch-disc engagement
controlled by an air-timer management system.


Deep stage: to roll a few inches farther into the beams after
staging, which causes the pre-stage lights to go out. In that
position, a driver is closer to the finish line but dangerously
close to a foul start.



Dial under: when drivers in Super Stock and Stock (handicap
categories) select an elapsed time quicker than the national
index. Drivers select a dial-under, or e.t., that they think their
cars will run based on previous performance. The breakout rule is
in effect.



Diaper: an absorbent blanket made from ballistic material, often
Kevlar, that surrounds the oil pan to contain oil and parts in
case of an engine explosion; required for Top Fuel, Funny Car, Top
Alcohol Dragster, and Top Alcohol Funny Car.



Dropped cylinder: when a cylinder runs too rich (too much fuel in
the air/fuel mixture) and prevents the spark plug(s) from firing.


Elapsed time: the time it takes a vehicle to travel from the
starting line to the finish line. Also called e.t.


Eliminations: After qualifying, vehicles race two at a time,
resulting in one winner from each pair. Winners continue in
tournament-style competition until one remains.



Foul start: indicated by a red light on the Christmas Tree when a
car has left the starting line before the green light, or starting
signal.



Full Tree: used in Competition, Super Stock, and Stock, for which
a handicap starting system is used to equalize competition. The
three amber bulbs on the Christmas Tree flash consecutively five-
tenths of a second apart, followed five-tenths later by the green
starting light. A perfect reaction time on a full Tree is .500.



Header(s): a fine-tuned exhaust system that routes exhaust from
the engine; replaces conventional exhaust manifolds.


Hemi: A Hemi engine has a hemispherical shaped cylinder-head
combustion chamber, like a ball cut in half.


Holeshot: when a driver reacts quicker to the Christmas Tree to
win a race against an opponent with a quicker e.t.


Hydraulic: when a cylinder fills with too much fuel, thus
prohibiting compression by the cylinder and causing a mechanical
malfunction, usually an explosive one


Index: the expected performance for vehicles in a class as
assigned by NHRA. It allows various classes of cars in the same
category to race together competitively.


Interval timers: part of a secondary timing system that records
elapsed times, primarily for the racers’ benefit, at 60, 330, 660,
and 1,000 feet.


Methanol: pure methyl alcohol produced by synthesis; used in Top
Alcohol Dragsters and Top Alcohol Funny Cars.



Nitromethane: Produced specifically as a fuel for drag racing, it
is the result of a chemical reaction between nitric acid and
propane.



Pre-stage: to position the front wheels about seven inches behind
the starting line so the small yellow lights atop that driver’s
side of the Christmas Tree are glowing. The next step is to stage
and be ready to race.



Pro Tree: used in Top Fuel, Funny Car, Pro Stock, Pro Stock
Motorcycle, Top Alcohol Dragster, Top Alcohol Funny Car, Super
Comp, Super Gas, and Super Street, which feature heads-up
competition. All three large amber lights on the Christmas Tree
flash simultaneously, followed four-tenths of a second later by
the green starting light.



Reaction time: the time it takes a driver to react to the green
starting light on the Christmas Tree, measured in thousandths of a
second. The reaction-time counter begins when the last amber light
flashes on the Tree and stops when the vehicle clears the stage
beam.



Sixty-foot time: the time it takes a vehicle to cover the first 60
feet of the racetrack. It is the most accurate measure of the
launch from the starting line and in most cases determines how
quick the rest of the run will be.



Slider clutch: a multi-disc clutch designed to slip until a
predetermined rpm is reached; decreases shock load to the drive
wheels.



Speed trap: the final 66 feet to the finish line where speed is
recorded.


Stage: to position the front wheels right on the starting line so
the small yellow lights below the pre-stage lights are glowing.
Once both drivers are staged, the calibrated countdown (see
Christmas Tree) may begin.



Supercharger: a crank-driven air/fuel-mixture compressor also
called a blower. It increases atmospheric pressure in the engine
to produce more horsepower.



Turbocharger: an exhaust-driven intake air compressor (see
supercharger).



Wedge: an engine with a combustion chamber resembling a wedge in
shape.



Weight transfer: critical to traction. Vehicles are set up to
provide a desired weight transfer to the rear wheels. Upon
acceleration, the front wheels lift and the weight shifts to the
rear wheels, which makes them less likely to spin.



Wheelie bar(s): used to prevent excessive front-wheel lift.
Okay, now that some knowledge have been imparted on you jokers out
there you can walk away smugly and be confident knowing that you
actually know more about your car and the sport. Feels good
doesn’t it? So the nest time somebody opens up a conversation
about drag racing, you can actually participate intelligently.
Word up!