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DRAG MANUAL

  
INTRODUCTION
DRAG STRIP LAYOUT
GLOSSARY OF DRAG TERMS  
TUBES  
BREAKDOWN OF DRAG RACING CLASSES - IHRA  
BREAKDOWN OF DRAG RACING CLASSES - NHRA 
  

INTRODUCTION 
to Drag Racing

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(1,320 feet) or an eighth-mile(660 feet). A drag racing event is a series of such two-vehicle, tournament-style eliminations. The losing driver in each race is eliminated, and the winning drivers progress until one driver remains.

These contests are started by means of an electronic device commonly called a Christmas Tree because of its multi-colored starting 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.

Two light beams cross the starting-line area and connect to trackside photocells, which are wired to the Christmas Tree and electronic timers in the control tower. When the front tires of a vehicle break the first light beam, called the pre-stage beam, the pre-stage light on the Christmas Tree indicates that the racer is approximately seven inches from the starting line.

When the racer rolls forward into the stage beam, the front tires are positioned exactly on the starting line and the stage bulb is lit on the Tree, which indicates the vehicle is ready to race. When both vehicles are fully staged, the starter will activate the Tree, and each driver will focus on the three large amber lights on his or her side of the Tree.

Depending on the type of racing, all three large amber lights will flash simultaneously, followed four-tenths of second later by the green light.(called a Pro Tree), or the three bulbs will flash consecutively five-tenths of a second apart, followed five-tenths later by the green light (called a Sportsman, or a Full Tree).

Two separate performances are monitored for each run: elapsed time and speed. Upon leaving the starting line, each vehicle activates an elapsed-time clock, which is stopped when that vehicle reaches the finish line. The start-to-finish clocking is the vehicle's elapsed time (e.t.), which serves to measure performance. Speed is measured in a 66-foot "speed trap" that ends at the finish line. Each lane is timed independently.

The first vehicle across the finish line wins, unless, in applicable categories, it runs quicker than its dial or index. A racer also may be disqualified for leaving the starting line too soon, leaving the lane boundary (either by crossing the centerline, touching the guardrail, or striking a track fixture such as the photocells), failing to stage, or failing a post-run inspection. (in NHRA class racing, vehicles usually are weighed and their fuel checked after each run, and a complete engine teardown is done after an event victory.)

  

DRAG STRIP LAYOUT


Pre-Stage beam:
A light beam-to-photocell connection in each lane that triggers the small yellow pre-stage lights atop the Christmas Tree. The pre-stage lights signal to drivers that they are close to staging, approximately seven inches behind the starting line.

Stage beam (starting line): This light beam-to-photocell connection controls the starting and timing of each race. It triggers an independent lane timer for elapsed time and will trigger the red foul light if a driver leaves too soon. A race cannot be started until both drivers are fully staged.

Guard beam: A light beam-to-photocell connection located 16 inches past the stage beam that is used to prevent a competitor from gaining an unfair starting line advantage by blocking the stage beam with a low-installed object such as an oil pan or header collector pipe. If the guard beam is activated while the stage beam is still blocked, the red foul light is triggered on the Christmas Tree and the offender is automatically disqualified.

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

Interval timers: Interval timers are part of a secondary timing system that records elapsed times, primarily for the racers' benefit, at 60, 330, 660, and 1000 feet. The eighth-mile speed light, located 66 feet before the 660-foot mark, is used to start the eighth-mile speed clocks in each lane; those timers record speed for the first half of the run.

Speed-trap and elapsed-time beams: The first of these light beam-to-photocell connections is located 66 feet before the finish line and is used to start the speed clocks in each lane. The second beam, located at the finish line, shuts off both the elapsed-time and speed clocks in each lane and triggers the win-indicator light. The 66-foot speed trap is where speed is recorded.

   
   CLICK HERE TO VIEW DIAGRAM OF DRAG STRIP LAYOUT
   

GLOSSARY OF DRAG TERMS


After Market
- Generally, the replacement parts and high performance products market.

Air Dam - Used to direct or block air flow. Used in front to prevent air flow to undercarriage, intended to prevent turbulence and lift.

Air Foil - Stabilizer, generally used to create down forces, increasing stability and tire-to-track adherence at high speeds.

Arm restraints - Restraining straps to restrict arm movement in a car accident.

Ballast - A controlled amount of weight, functionally positioned, used to help car meet class weight requirements.

Belly Pan - Generally, a skin of aluminum or fiberglass used to cover the under carriage of vehicle, assisting in preventing turbulence and air drag.

Blueprinting - The meticulous matching to factory specifications all parts and/or components. Dressing parts to absolute design callout or manufacturer's specifications.

Bleach Box - Section of track before the starting line where cars spin the tires in water.

Breakout - (Run Under) When your elapsed time is quicker than your dial-in, causes you to be disqualified.

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

Burn-out - Spinning of rear wheels at high RPM in water to heat and clean drive tire rubber prior to a run, resulting in increased traction.

Bye Run - A lone run given to a randomly chosen car, because of an unequal number of cars in the round.

C.C - Cubic Centimeter, a metric unit of volume measurement, equal to approximately 0.061 cubic inch.

C.F.M. - Cubic Feet per Minute. A measure of volume.

C.I.D. - Cubic Inch Displacement. A measure of volume.

Camber
- Tilting of the top of the wheels from the vertical. When tilt is outward, camber is positive.

Caster - Tilting of steering axis forward or backward to provide directional steering ability. Positive caster recommended for drag racing.

Catch-can - A container used to catch liquid overflow, preventing spillage on race track. Also known as catch-tank.

Christmas Tree - An electronic starting device incorporating calibrated lights displaying a visual countdown for each driver, activated by a designated official.

Chromoly - Also Chrome Moly. Short for Chromium Molybdenum steel. A very strong and light tubing highly adaptable for race cars.

Chute - Short for parachute or drag chute. Used to assist high-speed braking.

Clutch can - Bell housing, the bell-shaped housing used to encase clutch and flywheel.

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

Competition Area - The staging lanes and race track surface.

Deep Staging - When the racer inches his car forward, not completely passed the starting line (staging line) so much as to turn off the staging light.

Dial-ins - Driver's predictions of E.T.'s their cars will run in their first eliminations.

Dialing Under - Allows competitors in Stock and Super Stock the option of selecting a time faster than the National Index. Applied in handicap elimination racing where breakout is in effect.

Diaper - A blanket made from ballistic and absorbent material, often Kevlar, that surrounds the oil pan and serves as a containment device during engine explosions.

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

Dropped cylinder -
When a cylinder becomes too rich (too much fuel in the air-to-fuel mixture) and prevents the spark plug (s) from firing.

Dry Hops - Process of spinning your tires on dry pavement.

E.T.
- (Elapsed Time). The total time it takes to get from the starting line to the finish line.

Eliminations - When cars are raced two at a time, resulting in one winner and one loser "eliminated". Winner continues to race in a tournament-style competition.

F.I.A. - International Federation of Automobile Clubs. Sole international body governing motoring sport.

Ferrous - Containing iron, as in metals.

Fishtail - Aft lateral oscillation, generally the result of traction loss.

Final MPH Light Beam - Shuts off MPH computer.

Finish Line - Line which determines winner and computes Elapsed Time.

Finish Line Light Beam - Light beam to shut off elapsed time computer and signals win indicator and elapsed time.

First MPH Light Beam - Light beam to start MPH computer.

Flash Shield - A device to encompass the air inlet of a carburetor's sides, top, rear. To protect driver in case of engine backfire.

Foul Start - Leaving the starting line before the green light starting signal.

Fuel Check - A tech station used to inspect fuels to insure content is within limits allowed for that particular class. Analysis of fuel.

Fuel Injection - (F.I.)A system replacing conventional carburetion which delivers fuel under pressure into combustion chamber of air flow prior to entering chamber.

Full Tree - The method used to start cars at the starting line. The method used is one yellow light is used at a time, then the green light. As opposed to all yellow lights are lit at once then the green light (Pro-Tree). The reaction time used in full tree is .500.

Gilmer Belt - Toothed or splined drive belt used with matching pulley, generally a non-slip drive belt.

Guard Beam - Light beam to alert officials if driver starts to race before the green light appears. Often called a foul start.

Gusset - A reinforcement addition adding web-like or triangulation reinforcement to car structure, usually welded in place.

Halon - Special Freon Fire Extinguisher. Generally a 3% to 5% concentration will extinguish fire.

Handicap - When one car is faster than the other, the slower gets a head start. Headstart depends on previous elapsed times or dial ins.

Headers - Fine-tuned exhaust system routing exhaust from engine. Replaces conventional exhaust manifolds.

Hemi - Generally an engine with a combustion chamber having resemblance to a hemi-sphere or round ball, cut in half. Spark plugs are also located in center of head, not to one side.

Hole Shot - Starting-line advantage achieved by the quicker reacting driver.

Hydralic - When a cylinder fills with too much fuel, thus prohibiting compression by the cylinder and causing a mechanical malfunction, usually an explosive one.

Index - Elapsed time assigned by NHRA or IHRA to allow various classes to race together with an equitable handicap starting system.

Inline - Cylinders in a single row, valve stems in a single row.

Interval timers - Interval timers are part of a secondary timing system that records elapsed times, primarily for the racers' benefit, at 60, 330, 660, and 1000 feet.

Ladder Bars - A 3-point traction device with 2 attaching points at rear axle housing and 1 point at frame.

Length of Track - 1320' 1/4 mile distance from start to finish.

Lexan - A trade name of General Electric used for a durable thermal resistant plastic material used where transparent material is required (i.e.., face plates, goggles, windows, etc.)

M.I.G. - Metal Insert Gas Arc welding. Uses a continuous-feed filler rod material pulled through the torch from a roll of wire.

M.P.H. - Miles per hour.

Magnaflux - The process of using a special electromagnet and magnetic powder to detect cracks in iron which may be invisible to the naked eye.

Methanol - Technically pure methyl alcohol CH3oh(toxic) produced by synthesis.

Minimum weight - The lowest allowed weight for the vehicle in it's class.

Nomex - Trade name of DuPont, a fire-resistant fabric used in the manufacture of protective clothing.

O.E. - Original Equipment (as originally produced and installed by factory manufacturing automobile.) Originally equipped.

O.E.M. - Original Equipment Manufacturer. Original Automobile Manufacturer.

O.H.C. - Overhead Cam.

Otto Cycle - The four operations of intake, compression, power, and exhuast(4-cycle engine). Named for inventor Dr. Nikolaus Otto.

Permanent - Pre-assigned, registered competition numbers assigned by NHRA or IHRA.

Pilot Chute - A spring-loaded device which pulls the braking chute from its pack.

Pits - Where the race cars are worked on.

Pre-Staged Light Beam - Light beam used to warn drivers they are inches away from starting line. This beam when broken by front wheels sets off pre-staged bulb on top of the Christmas Tree.

Planetary Transmission - A transmission in which the various gears revolve around one another. Consists of a sun gear, carrier with planet gears and ring gears. Also known as overdrive or underdrive.

Port - The opening in an engine where the valve operates and through which the air-fuel mixture or exhaust passes.

Protest - A complaint filed against a competitor, investigated by officials.

Pro-Tree - The method of starting cars from starting line, using the Christmas tree. Method used is all three yellow bulbs light then green as opposed to one yellow light at a time then green (full tree). Also uses a reaction time of .400.

R.P.M. - Revolutions per minute.

Rake - Bottom of body not parallel to ground (lower in front).

Reaction Time - Computed in thousandths of a second and is the time how quickly you moved off the starting line after the go signal.

Return Road - Road which leads from shutdown area back to the pits or staging lanes.

Round - When all cars in a bracket (class) have made a run.

Shutdown Area - Area located after finish line for racing cars to slowdown.

Speed Trap - The final 66 feet to the finish line, known as the speed trap, where speed is recorded.

Staging Director - A person who directs the flow of traffic from the staging lanes to the race lanes.

Staging Lanes - Lanes where drivers line up and wait to make a run down the track.

Staged Light Beam - Light beam used to warn drivers they are on the starting line ready to race. This beam when broken sets off staged bulb on top of the Christmas Tree.

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

Tech Area - Area where Drag Officials inspect tires, steering, brakes or anything that might be a safety hazard before time trials.

Time Slip - Printout of Elimination information.

Time Trials - Practice runs.

Timing Booth - Printouts of Elimination Elapsed Times are located here.

Traps - The two beams of light at the end of the drag strip which compute mile per hour.

Water Burnout - Process of spinning your tires in water to get the tires hot and sticky for

better traction.

Wheelie Bars - Bars attached to the rear of the car to prevent excessive front wheel lift.

   

TUBES


SLICKS

* It is left up to the racers judgment to run tubes in slicks. As a manufacturer, we suggest to leave it up to the customer unless the tires have an air retention problem. The added weight of the tube is not necessary.

* By running a tube in a slick, it is actually like applying an extra piece of rubber to the sidewall of the tire, thus making the sidewall stiffer.

* Use proper tube according to circumference of tire. Use following chart to determine proper tube for your application.

74/ 84-13 will fit 74" to 84" circ. 8" to 12" tread width

80/ 88-15 will fit 80" to 88" circ. 6" to 11" tread width

86/100-15 will fit 86" to 100" circ. 11" to 13" tread width

94/106-15 will fit 94" to 106" circ. 15" to 19" tread width

* If the tube is not the correct size for tire, the tube will make a bulge or indentation in the sidewall of the tire. When seeing this problem, check tube for proper fit.

* Natural rubber tubes, as compared to synthetic or man-made rubber tubes, are suggested for racing purposes. Natural rubber has a tendency to stretch more with heat and force applied, whereas synthetic rubber has a tendency over time become hard and brittle, thus causing the tube to split and deflate.


WARNING:

NOT FOR HIGHWAY USE: All Hoosier Racing Tires including DOT labeled Hoosier Racing Tires are designed for racing purposes only on specified racing surfaces and are not to be operated on public roadways. DOT labeled Hoosier Racing Tires meet Department Of Transportation requirements for marking and performance only and are NOT INTENDED FOR HIGHWAY USE. It is unsafe to operate any Hoosier Racing Tire including DOT tires on public roads. The prohibited use of Hoosier Racing Tires on public roadways may result in loss of traction, unexpected loss of vehicle control, or sudden loss of tire pressure, resulting in a vehicle crash and possible injury or death. Exception-"PRO STREET"

   

BREAKDOWN OF DRAG RACING CLASSES - IHRA  

   

 PROFESSIONAL

SPORTSMAN

Top Fuel 

Top Dragster

Pro Stock 

Top Sportsman

Pro Modified 

Quick Rod

Alcohol Funny Car 

Modified

Top Fuel Harleys   

Super Rod

Pro Outlaw

Super Stock

    

Hot Rod

   

Stock

    
    

BREAKDOWN OF DRAG RACING CLASSES - NHRA 

 

 PROFESSIONAL

SPORTSMAN

Top Fuel 

Top Alcohol / Dragster

Funny Car 

Top Alcohol / Funny Car

Pro Stock

Competition

Pro Stock Bike  

Super Stock

Stock

    

Super Comp

    

Super Gas

    

Super Street

    
   

Hoosier Racing Tire

Tires Designed For Champions