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APIRA Information
In its most basic form, drag racing is a race between two vehicles over a straight measured distance from a standing start. The accepted standard for that distance is either a quarter of a mile (402.336m) or an eighth of a mile (201.168m). Side-by-side races are started by means of an electronic device commonly known as a 'Christmas Tree'.

Upon leaving the startline, each contestant activates a timer which is, in turn, stopped when the same vehicle reaches the finish line. The start-to-finish clocking is the vehicle's ET (Elapsed Time), which serves to measure performances and often serves to determine handicaps during competition.

Because of the wide variety of vehicle types which are eligible to compete, a system of time brackets ranging from the quickest through to the slowest has been developed (ET Bracket Racing) to allow the creation of separate 'knock-out' eliminations.

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ET Bracket Racing

ET Bracket Racing is subdivided into different time brackets and offers a good starting point for the novice wishing to become involved in the sport, while some racers choose to race vehicles they build to certain specifications to fit into a certain heads-up racing class.

ET Bracket Racing is a handicap race which gives the slower vehicle a head start. The difference between vehicle A starting first before vehicle B is determined by the difference of dial-in times by which each driver/rider writes his ET on the rear of the vehicle providing it is within the times of his particular bracket.

For example Sportsman ET runs within a time bracket of 12.00 to 13.99. Driver A may dial-in a time of 12.50 seconds and driver B a time of 13.30 seconds. A quick calculation reveals that driver B gains.8 of a second advantage at the start from the activation of the green light in his lane only. Driver A on the activation of the green light in his lane has to
catch driver B to win the race thus making for close competitive racing at the finish line.

However, neither driver may run quicker than the time with which they dialed in because to do so would mean instant disqualification (known as a 'Breakout') giving the other driver the automatic win to the next round. If both drivers run quicker than their dialed in times then the winner is determined by the driver who broke out in the least amount of their dialed in time. For example driver A dialed in at 12.50 seconds and driver B dialed in at 13.30 seconds. At the finish driver A ran 12.10 and driver B ran 13.20 seconds. Driver B becomes the automatic winner because he broke out the least.

Another form of disqualification is a foul start (or Red-Light). This happens when the driver reacts to the 'Christmas Tree' too quickly and drives away from the starting line before the green light. Should dual infractions occur, say a red-light and then a break-out, the redlight would be classified as the worst infraction.

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Timing and Starting System

Electronic clocks actuated by photocells on the track are used to time every run. These are measured between the start and finish lines. The first time is quoted as the E.T. (Elapsed Time) for the run, and the second time is used to calculate the average speed of the vehicle at the finish. Each lane is independently timed during qualifying and the E.T.'s recorded are used to determine the pairings in the eliminations.

During the eliminations, however, the two systems are interconnected, so that as well as giving times and speeds, the finish line photocells also detect the first vehicle to cross the finish line to within 1/100.000th of a second. Under normal circumstances, i.e.; no foul starts, this determines the winner of the race.

Because of the large difference the cars position at the start can make to both the times used in qualifying and in the determination of foul starts, the way in which the starting of the car is arranged plays a significant part in ensuring fair racing. Therefore, to achieve impartiality in this respect, very sensitive electronic photocells are used to determine the
cars' position and movement at the start line. The actual starting is done by a device which is situated in the middle of the track and commonly known as the 'Christmas Tree', to which these photocells are connected.

When a vehicle is called to the start line by the Call-Up Marshal, these photocells directly control the turning on of the staging lights to indicate to the rider/driver that he/she is either too far back, correctly staged, or too far forward. When the starter is satisfied that the vehicles in both lanes are correctly staged, he actuates the countdown.

After this, provided the car has not moved during the countdown, the green light replaces the amber, signaling that the car can cross the start line. If at any time during the countdown the vehicle moves too far, which is considered to be a foul start, the photocells detect the movement, stopping the countdown and switching on the red light to indicate the foul start.

There are two types of light sequence starts, the three-amber 'Pro Tree' with all amber lights activated simultaneously with a four-tenths of a second delay to the green, and a 'Sportsman Tree' with a full tree-amber countdown with a five-tenths delay between lights.

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Affordable Accuracy with Portratree
Many track owners around the world are overwhelmed by the cost of a new timing system. Most cannot believe the costs involved. But the people at PortATree Timing Systems based in the United States believe that they have addressed this problem by developing a turnkey timing system at an affordable price.

After installing a PortATree professional System at Shakespeare County Raceway in 1998, the track has now joined the ever growing list of PortATree run raceways around the world.

Last year a series of new software packages were installed by APIRA systems operators Wayne Schreier, Janet Nobes and Simon Day for a much quicker and safer application during race events.

Revisions included scoreboard display times, instant access to racer information for commentators, a quicker log of qualifying and ladder printouts for each class.

The PortATree computer has been tested by the MSA's [Motor Sports Association] recognised tester and is accurate to 0.001 of a second. In fact, Shakespeare County Raceway is the first UK drag strip to have such a system checked and certified.

In light of British, European and World records being set at Shakespeare County Raceway the track distance has also been measured by an independent contractor and a certificate has been issued for its accuracy.

The latest European track to join the list of PortATree users is based in Scotland at Crail Raceway. There system was installed late last year and will be run purely on a Run What You Brung basis.

The PortATree Professional Racetrack Timing System was developed by Al Smyth and drag racer Ted Gregorius. The two got together in early 1990 when Gregorious contacted PortATree for help with a sand drag racing timing system that he was working on. In addition to drag racing PortATree Timing Systems have been used at Drag Boat, Snowmobile, Mud and Street Luge racing events.

PortATree Timing Systems also receives endorsements from drag racing Top Fuel legend 'Big Daddy' Don Garlits and former NHRA Super Gas and Super Comp champion David Rampy.

Check out the official web site at PortATree (

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On Race Day
Your race weekend admission passes will allow entry to you, your crew personnel, your race vehicle and tow or service vehicle. As soon as possible, proceed with your vehicle to the appropriate Scrutineer who will also want to see your MSA or ACU Competition License, helmet, race suit etc.

Once through scrutineering you must then sign-on at the tracks Pit Control, producing the scrutineer's ticket, Competition License and APIRA Club membership Card. Members of your crew are also required to sign-on and be issued relevant track passes. If not signed on they will not be allowed to assist you and your vehicle during start-up.

Move into the staging lanes when you are ready and wait for an APIRA Official/Staging Lane Marshal to indicate when you can make your first qualifying run at the allotted time for your bracket. Check Final Instructions or at Pit Control for time table of qualifying periods.

When qualifying has ended, normally Saturday evening of a 2 day event, pairing for the next days eliminations will be worked out and competitors duly notified. Check the time of your first elimination round, again referring to your Final Instructions and time table.

When your elimination is called to the Staging Lanes by APIRA Pit Marshals and by P.A. announcements, you will be paired up with your opponent and the Staging Lane Marshal will indicate when you should move to the startline.

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Run What You Brung
A 'Run What You Brung (RWYB) event isn't a racing event. It is a means of practicing away from open competition and are usually organised separate to any organised events.

Anyone can enter on the day provided they have a normal DVLC FULL road driving license, correct specification crash helmet, and seat belts in their car can come along and gain drag racing experience. A full safety check of the vehicle, crash helmet etc will be made before you're allowed access to the track. Signing on will take place at Pit Control. The same safety check will be made for road legal Motorcycles.

Any race vehicle that attends a RWYB event must comply with the General Safety Regulations and Class Requirements which apply to the vehicle and driver/rider under normal race conditions, and must be scrutineered. Should a vehicle be deemed not road worthy it will not be allowed to take part until the problem is put right to the satisfaction of the scrutineer.

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A Beginner's Guide to Track Talk
What are all those lights on the pole near the startline for?
The small yellow lights at the top of the "Christmas Tree" let the driver know when he is on the starting line. The much larger ones beneath it indicate that the green will soon blink on. Green, of course, means go. Red, which may flash instead of the green, indicates that a driver has left the line too soon and is automatically disqualified.

What do pre-stage, stage and deep-stage mean?
A driver is pre-staged when he is eight inches behind the starting line and the tiny yellow light at the top on his side of the 'Tree' is glowing; it's his last chance to prepare for the race at hand. He is staged when his front wheels are right on the starting line; he has to be ready now because the green 'go' light may flash on at any moment. The driver is deep staged when he has rolled a few inches further and his pre-staged light has gone out; he is now closer to the finish line but dangerously close to a foul start, too.

How can one car cross the finish line first and still lose?
Drivers who 'red-light', or foul start, usually do get to the finish first because they took an unfair advantage at the start. But no matter how wide their lead grows, they've already lost; a 'red-light' start is an instant disqualification. Drivers in Super Comp, Super Gas and Super Street - all categories designed to accentuate driving prowess and not car performance - can get to the finish line first and still lose if they break out, which is to run quicker than their designated index.

Why are some cars warmed up in the pits?
Crews heat engines for two reasons: to ensure that their high-powered motors will be at the proper operating temperature when they get to the starting line; and, as might be expected, to 'test-fire' check that no loose bolt or leaky gasket has been left behind from a frantic between rounds thrash.

What is the significance of a burnout?
Drivers leave clouds of dust in their wake in this pre-race procedure, which heats the soft rubber tyres and makes them adhere to the track even better on the ensuing run. Burnouts also help bring engine temperature up to its proper level for racing. And they're fun to watch.

What is the 60 foot time commentators are always referring to, and why is it important?
The 60-foot time is the time it takes a driver to cover the first 60 feet of the race track. It is the most accurate measure of how well the driver launched from the starting line, which in most cases determines how quick the rest of the run will be.

Why do rear tyres 'grow' as cars pick up speed?
They don't just appear to grow; they do grow due to centrifugal force. The faster the rear tyres spin (and the faster the car goes), the greater the force outward from the centre of the wheel.

Why do cars catch fire?
Fires are usually caused when oil from a catastrophic engine failure escapes through a hole in the block and splashes onto red-hot exhaust headers, where it ignites.

After a car has oiled the track, what does FAST [Fire & Accident Safety Teams] put on the track?
The FAST crew pours rice hull ash, which acts as paper does when blotted on spilled ink, on the track to soak up the offending liquid.

What safety equipment protects the driver?
All vehicles, from Top Fuel dragsters to street cars, carry on-board fire extinguishers. Most racers drive in the protective cocoon of a lifesaving chromoly steel roll cage and wear multi-layer firesuits and arm restraints.

How is it determined who races whom?
The first day is devoted to qualifying. Once qualifying is complete, the cars and bikes are then paired on an elimination ladder in their respective classes. The higher the driver has placed himself on the ladder in qualifying, the slower the first round opponent.

Why do some cars have numbers temporarily painted on their windows?
These numbers, usually seen on E.T. Bracket and VWDRC category cars, indicate to race officials in the control tower what index the driver is 'dialing'. That is how the 'Christmas' Tree' is programmed to give handicap head starts in handicap racing. The figure on the window is the drivers own estimate of how quickly he expects to cover the quarter mile.

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Drag Racing Jargon Explained
The airfoil is the same thing as a wing - a stabilizer, generally used to create down force, which increases stability and tyre-to-track adherence at maximum speed.

Used only in handicap, break out refers to a competitor running quicker than he 'dialed-in' for his race (predicted how fast he would run). Unless the opponent has committed a more serious foul, the driver who breaks out has lost.

A burnout, that is to spin the rear tyres in water to heat and clean drive tyre rubber prior to a run for better traction, precedes every run.

Christmas Tree:
The 'Tree, as it is often referred to, is the noticeable electronic device between lanes on the starting line that incorporates calibrated lights displaying a visual countdown for each driver.

Short for parachute, the 'chute cuts a cars speed virtually in half when released.

The dial-in is the number indicating elapsed time, written in shoe white on a handicap-classed car's window, that the driver thinks his car will run. Because a driver must arrive at the finish line first without running quicker than his dial-in, handicap racing ensures that the driver with the best starting line reflexes will win almost every time. This form of racing applies to E.T. bracket cars and some VWDRC classes.

In an engine, displacement is the total volume of air/fuel mixture the engine is theoretically capable of drawing into all cylinders during one operating cycle.

Elapsed time, or E.T., is the time it takes to go from the starting line to the finish line. It is the most important number in drag racing.

Foul start:
A foul start is designated by a red-light left at the bottom of the Christmas Tree when a car has left the starting line before receiving the green light.

A driver can win a race over a faster driver by reacting quicker to the Christmas Tree starting lights, making use of a holeshot.

Headers is another term for exhaust. Each exhaust outlet has its own pipe, unlike a conventional exhaust manifold.

A hemi engine has a hemispherical shaped cylinder head combustion chamber.

The index is the expected performance for a car in a given class. It allows various classes to race together with an equitable handicap start.

An electrical device which locks up the front wheels only so that the rear wheels can rotate freely without the car moving for the duration of the burnout.

Technically, this fuel is pure methyl alcohol for use in Alcohol Dragsters and Funny Cars.

Stands for revolutions per minute. Is a measure of engine speed as determined by crankshaft spin.

To be 'in stage' is to be correctly waiting on the starting line. When both cars are staged the Christmas Tree sequence will begin.

The supercharger, or blower is a crank driven air/fuel compressor. It raises atmospheric pressure in the engine, resulting in added horsepower.

Slider Clutch:
The multi-disc slider clutch is designed to slip until a predetermined rpm, where it finally locks up. It decreases shock load to the drive wheels.

Shutdown area:
The run-off at the top end of the drag strip where cars slow down before turning back towards the pits.

An affectionate term for front engine dragsters. These can be found racing in the Wild Bunch.

A turbocharger is an exhaust driven intake air compressor.

Traction bars:
Traction bars control rear end torque and stabilize suspension. They transmit torque to the frame, increasing traction.

A two-step is used primarily on ACU/UK Championship Pro Stock Bikes. This electronic device enables riders to programme a specific rpm range for the launch.

Wheelie Bars:
Wheelie Bars prevent excessive front wheel lift and keep hard launching cars from flipping over.

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