Life in the Fast Lane - Dale Smith on NHRA

Ok class, settle down and take your seats. Welcome to
 “Intro to Drag Racing”

 I am your instructor for this course. If any of you have ever raced at a drag strip, you really shouldn’t be here. But if you feel compelled for a refresher, then you are more than welcome to stay.

To begin with, lets outline various points of interest, and then we’ll address each one in detail. We will cover how a drag race works; functions of the car and timing equipment, history of the sport, and various classes and sanctioning bodies. Since this might take a while, we’ll just cover one point of interest per class meeting. For today’s class we will go over functions of the car and track. As most of you know, the typical length of the track is ¼ mile (1320 ft.). There are some tracks that are only half this distance, and are quite common in the South East United States. Why that is will be discussed in the history portion, so please hold your questions till then. But whether the track is the more standard ¼ mile or 1/8th mile, the way a drag race works (procedures, timing, etc.) it is the same.

I will assume that you do know a drag race is an acceleration contest between two vehicles. Competition is conducted in rounds of elimination till there is only one winner. If you ever watch Professional Tennis, it is much the same way. There are also two formats in how a pair of cars (or bikes) competes against each other. First is the most common, referred to as “heads up”. This is defined as both competitors racing leave the starting line at the same time, and first one to cross the finish is the winner. The other format is a bit complex for the first timer, and this is called “handicap”, where cars of varying performance are equalized by a handicap start. To better understand the latter format, one must understand the timing system employed by drag strips today.

The timing system used today is far from the handheld stopwatch. In fact, you won’t see anyone seriously using stopwatches at a drag strip. Being that performance is clocked to within .001 of a second, and some cars can repeat runs within this range, the timing system is handled by computer aided clocks. Each lane is independently timed, so no matter what is going on with the car next to you, your time is based on what you did in your lane. Each lane also is broken down in segments usually providing a 60 ft, 330 ft, 660 ft, 1000 ft incremental times as well as the overall time for the whole 1320 feet. Along the way you will also get a speed recording at each point of the track. This can certainly help you determine where your cars performance may differ; just because this run was slower than the last, did it fall off at the start, mid-way, or down at the finish. You can imagine how this can be a good tuning aid for car and driver.

Now how does this stuff work while you are on the track? To begin with, the clock doesn’t start in your lane till your car moves from the starting line. Even though the starting system, referred to as the christmas tree, is in the form of amber lights preceding a green light, once the green light comes on, as long as your car has not moved, the clock hasn’t started. Oh sure, the car next to you might be on it’s way, and is inferior in performance, but once you get going, if you cannot pass your competitor before you get to the finish line, you are on the trailer. This illustrates how a car with a slower elapse time can actually beat a car that is quicker (write down this term, “reaction time”, we’ll get into this later in the discussion). Also note, speed doesn’t win a drag race, elapse time does. It is all about how little time it takes to go from A to B, no matter what top end speed you record. There are benefits to knowing the trap speed at each increment, and as an example, knowing your cars typical top speed, if it is considerably lower on a particular run, may indicate to you (the driver) lifting off the throttle a bit soon. Oh, and there is anther thing about some big mph; the faster the speed, the more it strokes the ego.

Ok, lets get back to the topic of the clocks. Now I did say that the clock doesn’t start when the green light comes on, so how does it work? Photo cells! The starting line has a set of photocells and with each increment down track there is another till you get to the finish. All of these are tied into the computer for each lane. To better illustrate we have come out to Moroso Motorsports Park to show you what this equipment looks like, where it is positioned, etc.

We are on the starting line and what you see here are 3 photocells. The first two will make up the starting line, and this is where your front tire is to be positioned in order for the car to be properly staged. The 3rd photocell you see has a unique use that involves a couple of issues that we’ll come back to. For now we’ll just focus on the first two cells. As you pull up to the starting line your tire will break this first beam, which will illuminate the pre-stage light on the christmas tree. This will alert you to how close you are to the final stage beam. You just inch a little further until the stage light is also illuminated and hold the car there. For some of you newcomers who have been to a track, now you see why you don’t need your buddy standing in front of you to tell you the front of the car is on the starting line.

Now you are properly staged on the starting line, you hold the car so it doesn’t roll out of the staging beams. The official starter will take a moment to make sure you are ready and the track is clear, then throw a switch which activates the christmas tree with a series of amber lights followed by the green. When you leave the line, and the front tire slips out of the stage beam, the clock will start. As your car progresses down track, the front tire will pass through the beams at every increment to give you an elapse time to that point along with your mph. This will continue till you go through the finish line where your overall elapse time and top speed will be recorded. See, not only will you not spend a night in jail if you do this on a real track, but I doubt your buddies can line up down the avenue and give you such wonderful information.

Obviously once you have passed the finish you will want to lift off the throttle and start slowing down. Some tracks have a very generous length to the shutdown area, but don’t assume so. All you need to do is go to a track that has a shorter shutdown, and if your car is fast enough, you may get to see life where the pavement ends. Get on the brakes hard enough, but with control till you reach the turn-off (most tracks have several turn offs). Pull off the track and head back down and you’ll see an area where you will receive your time slip. Ahhh, and you thought that was a toll booth or a border crossing; nope, just a place to get the slip of paper to see how you did.

More next week..