Bracket Racing 101: It's All In The Timing, Pt. 1
(Find more More Bracket Racing 101 articles HERE)

Everything we do on the dragstrip relates to time. We put a time on our windows, we try to leave on time, and we’ll hit the brakes at the stripe to kill some time. Yet with all of the importance of time to what we do, there are racers who don’t fully understand the timing system of the dragstrip.

In my travels racing at Northeast dragstrips I’ve gotten to know Al and Sue Smyth of Portatree Systems (www.PortaTree.com). The Smyth family is extremely active in our sport. Al races a stick SS/AH 1968 Barracuda, son Stephen races a 2009 A/SA Hemi Challenger, and daughter Allison races a C/SA 1997 Firebird. Practice trees, full competitive drag racing timing systems, and simulators are all part of the products that Portatree manufactures. As someone who founded and runs a company that makes timing systems for dragstrips, I thought Al would be a great source of information. This issue we’ll be focusing on the components we encounter at the starting line, such as the pre-stage and stage beams, Autostart, and Crosstalk. Next issue we’ll be looking at the timing components down track.

You’ve completed your burnout and are inching toward the starting line. Unless you’re driving a top fuel car you don’t need a person or ten to guide you into the beams: that’s what the little bulbs are for. Let’s look at those bulbs and the beams that trigger them. “A standard drag race track start line consists of a Pre-stage, Stage, and Guard beam,” said Al. “The guard beam is the actual starting line and all down-track measurements are made from this location. The Pre-stage and Stage beams are 7 inches apart and the guard beam is typically 15 inches out in front of the stage beam. The 60 foot clock is actually 61 feet 3 inches from the stage beam.”

Al continues, “The main thing racers talk about regarding the starting line is the rollout. When we set the rollout at a facility, we first make sure that the beams are parallel and square with respect to the 60 foot beams and the centerline of the track. Once we know that the start line is square then we set the rollout which is changed by raising or lowering the beams. If you measure the height once the rollout has been set, the beam is usually about 2 1/8 inches over the track surface.”

Two starting-line components that some racers are not clear on are Autostart and Crosstalk. “Autostart consists of four parts; Stage On time, Stage-to-Start time, variable delay, and the Time Out setting. Stage On time tells the computer that the vehicle is actually staged and is not just a flickering bulb. Once the second car to stage meets this condition the computer proceeds to the next cycle, Stage-to-Start, which is the minimum time once the last vehicle has staged. It is a fixed time set for each category as different categories require different Autostart parameters. Variable delay is the delay time after the Stage-to-Start time has expired. The Time Out setting is the time the computer will wait before starting the tree sequence whether the last car is staged or not; in other words this setting occurs when both drivers are pre-staged but only one is staged. Once this condition is met, the time out period begins.”

Crosstalk is another area that some don’t fully understand. “Crosstalk was introduced when tracks began using dividers and/or LED bulbs on the tree.” Until then, racers with a crossover delay could watch their opponent’s top bulb and react off that bulb. Dividers and LEDs changed that because it was no longer possible to see the opponent’s bulb. “With Crosstalk your top bulb comes on precisely at the same time as your slower opponent’s top bulb during a handicapped start.”

Next time our focus will be the timing increments down track to the finish line. Until then, thanks for reading and good luck at the track.


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