Drag Racing 101

Tuesday, March 20, 2018

Glossary

Breakout: Used only in handicap racing, "breakout" refers to a race car running quicker than the driver has predicted. The driver's prediction is called the dial-in and is posted on the race car. The driver who breaks out loses the race unless his or her opponent has committed a more serious foul, such as a red-light or crossing the centerline of the drag strip.

Burnout: Spinning the rear tires in water to heat and clean them before a run for better traction. In most classes, a burnout precedes every run down the drag strip.

Christmas Tree: The noticeable electronic starting device between the lanes on the starting line. It displays a calibrated-light countdown for each driver.

Elapsed Time (e.t.): The time it takes a drag-race vehicle to travel from the starting line to the finish line.

Methanol: Pure methyl alcohol used as fuel in Top Alcohol Dragsters, Top Alcohol Funny Cars, and even some Jr. Dragsters.

Nitro-methane ("nitro"): Made specifically as a fuel for drag racing, it is the result of a chemical reaction between nitric acid and propane. Top Fuel dragsters and Funny Cars use nitro methane.

Nitrous Oxide ("nitrous," "N2O"): When injected into an engine under pressure, nitrous oxide gives the engine a sudden boost in power by introducing more oxygen into the fuel mixture. Nitrous oxide is not allowed in any NHRA category except Pro Mod (exhibition) and some E.T. bracket classes.

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. A perfect reaction time is .000.

Red Light: When a race car leaves the starting line too soon — before the green light, or "go" signal — it activates the red light on the Christmas Tree and the driver has automatically lost the race.

Drag Racing 101

What is a Drag Race?

In basic terms, a Drag Race is an acceleration contest from a standing start between two vehicles over a measured distance at a specifically designed Drag Race facility.

The accepted standard for that distance is either a Quarter-Mile or an Eighth-Mile. In HO scale, a Quarter-Mile is recognized as 20.75 feet. Typical Track voltages may vary (from 18-26 VDC) and available amperage should really be at least 8 AMPS per lane.

Drag contests are started by means of an electronic device commonly called a "Christmas Tree." Upon leaving the starting line, each contestant activates a timer which is, in turn, stopped when the same vehicle reaches the finish line. That Start-to-Finish clocking is the vehicle's E.T. (elapsed time), which serves to measure performance and often serves to determine handicaps during competition.

What is E.T. Bracket Racing?

By far the most popular form of Drag Racing is a handicapped form of competition known as "E.T. Bracket Racing" or just "Bracket Racing". In this form of Racing, two vehicles of varying performance potentials can race on a potentially even basis. The anticipated elapsed times for each vehicle are compared, with the slower car receiving a head start equal to the difference of the two. With this system, virtually any two vehicles can be paired in a competitive drag race. You heard right! With this type of Racing, a T-jet can still beat a Fully Modified NEO Patriot - believe it!

An example:
Let's say Car A has been timed a 1.78, 1.74, and 1.76 seconds for the quarter-mile, and the driver feels that a "dial-in" of 1.75 is appropriate.

Meanwhile, the driver of Car B has recorded elapsed times of 1.27, 1.22 and 1.26 on the same track and he has opted for a "dial-in" average of 1.25.

Based on these "dialed-in'" times, Car A will get a .5-second head-start over Car B when the "Christmas Tree" counts down to each car's starting green lights.

If both vehicles cover the Quarter-Mile in exactly the predetermined elapsed time, the win will go to the driver who reacts quickest to the starting signal. That reaction to the starting signal is called "Reaction Time." Both lanes are timed independently of one another, and the clock does not start until the vehicle actually moves. Because of this, a 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! Assuming both cars consistently run their "Dialed-In" times every run, the Race is now won or lost based on the driver's reaction times! This is where 'coming off the line' can make or break the race. The "Dial-In" time is where each car chooses a dial-in time before the race, predicting the elapsed time the driver estimates it will take his or her car to cross the finish line. This is usually displayed on one or more windows so the starter can adjust the "christmas tree" starting lights accordingly. The slower car in the race is given the green light before the faster car by a margin of the difference between their two dial-in times

In principle, if both drivers have equal reaction times and their cars run exactly their posted dial-ins, both cars should cross the finish line at precisely the same time. In reality, this is an extremely rare occurrence. Measuring devices both at the start and at the end of the track post times down to 1/1000 of a second (0.001s precision), which makes tied races almost impossible.