The Basics
 

 
The standard drag race (commonly called "a Heads Up race") is two vehicles going from A to B with the first to reach B declared the winner. This is the standard form of drag racing at the professional level. Bracket racing is a variation on the standard drag race that many are familiar with.
 
Bracket racing modifies this format in an attempt to level the playing field for all so that anyone can compete with whatever vehicle they may own. The method used to equal things up is the staggered start. For example, lets say Big Bubba's Chevrolet Nova can run the 1/4 Mile in 11 seconds. Ineeda Car has a nice old Mustang that's not real fast but it's fun to drive. In time trials, he finds it takes him 15 seconds to get to the finish line. The respective times are known as their "dial in" and is written on their windows so that the timing officials can put the numbers in the computer. Ineeda draws Big Bubba in the first round, so they stage up. The computer in the timing tower will trigger Ineeda's light 4 seconds before it triggers Bubba's, giving Ineeda a head start. If both drivers were to leave the start line with a perfect .500 reaction and run exactly on their dial-in, there would be a tie. Don't worry, this has yet to happen. Timing things to the thousandth of a second coupled with human reactions pretty much prevents that. One either gets off the line first or misses their dial-in so there is always a winner.
 
If you leave before the green light comes on, the red bulb lights and you're disqualified for jumping the start. On the dial-in, if you run under your dial-in it's called a "breakout" and again you're disqualified for going TOO fast. With these controls in place the slowest VW can trailer the baddest Pro Street car in the city.
 

SAN ANTONIO RACEWAY
Basic ET Racing Rules
Races are run under the year 2005 IHRA rules

All cars are required to have working seat belts
Drivers in all cars running 13.99 or quicker (8.59) are required to have a Snell approved helmet, 80, 85, 90 of SFI 31.1 or 31.2 specs
All drivers are required to wear long pants and a tee shirt.  No tank tops are allowed
A roll bar is required in cars running 11.49 or quicker (7.49) except for convertibles which are required to have a roll bar if running 13.99 (8.59) or quicker
A drive shaft loop is required if the car runs 13.99 (8.59) or quicker with racing slicks or 12.99  (8.14) or quicker on street tires
Roll cages are mandatory in cars running 9.99 (6.99) or quicker
Drivers in cars running 9.99 (6.39) or quicker are required to wear a fire retardant jacket, pants and neck collar of SFI approved spec 3.2 A/5
Any car running 10.99 (6.99) or quicker is required to have a SFI approved harmonic balancer.  No stock balancers will be allowed
Full all leathers are mandatory for the riders of motorcycles running 120 MPH or faster.  Leather boots or shoes above the ankle, leather jacket and leather gloves are mandatory  for the riders of all motorcycles
Drivers of cars running 9.9 (6.39) or quicker are required to have a valid IHRA competition  license
Vehicles must have one functional tail light for night operations.  Flashing, blinking or  strobe lights will be fine
Any car running 9.99 (6.39) or quicker which has a full roll cage is required to have a SFI approved window net

No two steps, no throttle stops, no trans brakes, no delay boxes and no electric or pneumatic shifters in the Footbrake Class
All cars running 9.00 (6.39) or quicker must have chassis certifications.  Cars in the  Trophy eliminatory will be restricted to 13.00 or slower
 

TERMS and DEFINITIONS

 
Christmas Tree: The electronic starting device positioned between the lanes just ahead of the starting line.
Pre Stage: When your tires break this light beam, it's a signal that you are very close to the starting line.
Stage: Your front tires have reached the starting line. NOTE: The race typically will not be started until both drivers are staged. However, there is only a short grace period for staging. If you fail to stage in time, you will be disqualified (red light).
Countdown lights: Once the starter triggers the tree, these flash down at .500 second intervals with the green coming on .500 seconds after the last yellow.
Green: Pedal to the Metal
Red: Disqualified or foul

 
 
60' and 330' timers These give time and speed are various intervals on the track. Your 60' time is generally an indication of how well your car "hooks" - how much traction it has.
Auto Start In the center of the tree between the pre-stage and stage bulbs is a larger blue bulb. This bulb is turned on when the dial ins are correctly loaded into the computer and the tower is ready for you to make your run. Do NOT Stage your vehicle until this light is on. Once both racers are pre-staged, the starter and/or the tower arms the tree. When one racer fully stages, the other racer has 20 seconds to stage or the tree will go red for that racer and they will be disqualified. There is NO 2nd chance to stage once both racers have staged as the tree is committed and the Auto-start feature takes over. The tree is automatically activated after a 3 to 4 second delay after the last racer completely stages.
Bracket A specific class defined by elapsed time or required equipment. Example: Electronics, Footbrake
Breakout Running faster than your dial-in (you "dial" a 12.00, but run a 11.99)
Burnout Spinning the tires to clean them and to heat the rubber for better traction. Drag slicks work best at an elevated temperature. If you do not wish to do a burnout, you may drive around the water box.
Buy Back During the ET bracket program, there are buy-back entries into second round allowed in all classes except Quick. If you lose first round, and want to re-enter, go to the Ticket Booth at the pit entrance before second round is called to the staging lanes and register to buy-back into competition.
Courtesy Staging The first racer to light the pre-stage bulb must wait for their competitor to light the other pre-stage bulb.  The first racer may then perform their final staging maneuver. 
Crosstalk System
With this system, the tree is completely blinded.  The system computes the difference in dial-ins and holds the top yellow on for the difference in the dial-ins on the lane of the faster car.  The tree then  comes down as normal.  This is only used in the electronic type classes.  If you are using a cross-over box, you still put in both dial-ins just like usual.  The only difference is you let go on YOUR side of the tree.  If you are leaving first, there is no more difference than before.  The advantage of Crosstalk is you leave on your side of the tree, no matter what.  The only disadvantage is if you do not crossover and use a single lane delay box.  In that case, you would need to add the difference in dial-ins to your delay.
Dial-In The ET that the driver or crew chief thinks that the car will run. It is posted on the front and passenger side windows.
Double Breakout When both competitors run under their dial-in.  The one that runs closest to their dial-in is declared the winner.
Eliminations The actual race. Competitors are paired up by two's,  with only half coming back for the next round.
ET Elapsed time. The time from when the front tires leave the starting line beam until the front tires break the finish line beam. Reported to the thousandth of a second.
Heads Up Two cars racing with no handicap start. The classic drag race.
Sportsman Tree The bracket race tree where the 3 yellow lights flash at .500 second intervals and the green lights .500 seconds after the last yellow.
Pro Tree The three yellow lights flash on all at the same time and the green lights .400 seconds after.
Reaction Time The time between the driver's reaction to the last yellow of the tree and the time the front tires leave the staging beam. It can also be thought of as how close you came to leaving on the green light. It is printed on the ET slip. An example: .031  (.000 is a perfect light.)
What this really means is that your front tire(s) left the stage beam .031 seconds after the green light came on. The reaction time is also a combination of the driver's reactions to the lights and the car's reaction to the driver's input.
Red Light or Foul Start The red light is triggered by leaving before the green. It can also signal a foul or disqualification, like failing to stage in the required time or breaking something.
Staging Lanes Lanes marked off behind the burnout box area where the competitors are paired up for the race.
Time Trials A certain number of runs granted to each competitor giving each a chance to get their car ready for the race.
Water box/burnout box A small area kept wet by track personnel to help cars with slicks perform their burnout