For gearheads, there's little better place to be than the local dragstrip on a cool summer evening. Indeed, for anyone with blood running through their veins, the words "Test-n-Tune Night" should indeed raise one's pulse and get Metallica's "Fuel" cued up in the ol' mental jukebox.
Our beastly Impala SS is still laid up in the garage waiting for some new transmission internals (more on this soon!), but fortunately a couple friends from the local B-body club were nice enough to invite us along to US-131 Motorsports Park in Martin, MI. We'll start things off by providing some tips for those who haven't yet attacked the 1320.
First, a note on the difficulty of drag racing. We've noted some not-so-nice comments from our readers every time the topic of straight-line acceleration comes up, and we'll wager a guess that more than 90% of the haters have never lined up at a Christmas tree. Those who have decided to run their cars instead of their mouths will quickly learn that this is an extremely difficult endeavor - just as much, if not more so, as autocrossing.
The first thing that needs to happen after paying the entrance fee is to pass technical inspection. For most of us, that means wearing full-length pants (no shorts) and closed-toe shoes. Coolant systems must be vented into catch cans, and no more than 12" of non-stock rubber fuel line is allowed in the fuel system. A DOT, Snell, or SFI helmet is required if running quicker than 14.00, and frankly is a good idea in any vehicle (indeed, some tracks will require a helmet for all drivers). Those running aftermarket forced induction or nitrous now need to wear a single-layer fire jacket. If you can run the quarter under 11.50, a roll bar with a driver-side door bar is required, and those with drag tires on RWD cars will need a driveshaft loop. That covers most of the commonly-enforced rules for street cars, but call your track ahead of time if you have any questions.
Once your car has passed tech, park it for a few minutes to cool down, and walk around the track. You'll need to find the staging lanes, which serve as the queue for the track. If running on a pure test-n-tune night, it usually won't matter which of the 6-8 staging lanes you use, but there may be a couple of lanes set aside for grunge or "gamblers" races.
Vehicles are directed from the staging lanes to the strip by a track worker, who will indicate when it's time to pull ahead into the burnout box. If you're running treaded tires, avoid the waterbox, as the water will get flung up into the wheelwells and will drip back onto the tires as you wait to launch the car. This is not desirable. You also may leave behind enough water to screw up the vehicles behind you, which is even less desirable.
A worker will hold you back until the cars ahead stage and launch; once given the go-ahead, proceed with a burnout. Street tires will not react well to excessive heat, so doing a 20-second long burnout like John Force will only serve to make the tires too greasy for optimal traction. Instead, line up towards the back of the burnout box, spin up the tires lightly for 3-5 seconds, and then roll slowly towards the starting line. This will warm up the tires just enough to pick up some of the tire rubber and traction compound that's been deposited in the box, which is usually the best way to get street tires to stick. By all means, though, feel free to experiment with your technique.
Now it's time to stage the car at the starting line, and by this time your heart is pounding and palms are sweating. Stay calm, take a few deep breaths, and don't be rushed. Pull the car ahead slowly until the pre-stage lights are illuminated; this will happen well ahead of the "Christmas tree" (if you pull up alongside the tree, you've gone too far and will feel like a jackass when the starter asks you to back up to the starting line). The pre-stage beam sits about 8" ahead of the staging beam, the latter of which is the official starting line. Creep forward until the stage light illuminates; if it flashes and then goes out, you've gone too far.
Once you and the person in the other lane have staged, the tree will begin counting down. There are 0.500 seconds between each of the yellow lights, and another 0.500 seconds between the last yellow and the green. The "reaction time" is measured from the last yellow; cutting a "perfect light" is leaving exactly 0.500 seconds after the last yellow. Reaction times longer than 0.500 mean that the front wheels left the staging beam after the green light illuminated; a reaction time less than 0.500 means that the car left too soon, and the dreaded red light will illuminate.
The elapsed time counter starts when the back edge of the tire clears the beam, so a shallow stage (breaking the beam with the front edge of the tire) will give the car a foot or so of a head start at the expense of reaction time, while a deep stage (breaking the beam with the back edge) will show a quicker reaction time, at the expense of ET. When establishing an ET for bragging rights, use a shallow stage.
If you're at the track for the first time and if you're trying to simply establish the baseline performance of your vehicle, forget about trying to cut a good light. It's simply too much for most beginners to work on both their reaction time and launch techniques at the same time, so don't be afraid to leave a second or so after the green light comes on. Your reaction time will suck, but the reaction time is not factored into the elapsed time. Only once the car can be launched perfectly each time and every time should one start worrying about cutting good lights (or beating the guy in the other lane, for that matter).
Launching a car is an art in itself, and will be highly dependent not just on the vehicle but also the track conditions (which can vary from lane to lane and will likely change throughout the night). For vehicles with automatics, it usually pays to "powerbrake" the car by holding the brake with the left foot and applying some throttle with the right; the car is then launched by letting off the brake and applying as much throttle as the drive wheels will hold. Manuals will typically be more difficult to launch as the clutch and accelerator must be coordinated. In either case, it will typically be a fine line between using insufficient throttle and bogging the engine or applying too much power and blowing away the tires. Practice and patience are the keys here, and it make take several evenings at the track to figure out what works for any given car. Don't be afraid to ask for hints from other racers, but remember that even small differences between vehicles may result in dramatically different optimal launch techniques.
The launch is by far and away the most critical part of a quick run down the strip, especially for vehicles with automatics (those driving manuals will be provided with an opportunity to slow down the run during every shift). The reason is simple; the car is moving the slowest here and wasting the most time, so get the damn thing moving!
Once the vehicle is out of the hole, keep the vehicle accelerating as hard as possible until you've cleared the finish line. The elapsed time, or ET, measures how long it took to run the entire 1320 feet of the track. The trap speed shows the average speed of the vehicle over the last 66 feet for the track. While ET is affected dramatically by the quality of the launch, the trap speed will vary much less. For this reason, the trap speed can establish a useful measure of the vehicle's power-to-weight ratio, and is often used for bragging rights by owners of cars that simply cannot hook up at the starting line. Careful monitoring of the trap speed can also serve useful to determine the effect of weather conditions on the vehicle's power output.
At the end of the run, you'll have to turn off onto the return road. If you're in the outside lane, don't cut across the path of the vehicle on the inside. If you're on the inside, obviously, beware of the vehicle on the outside. On the return road will be a scale so that the vehicle's real-world weight can be established, and a person will hand out time slips at the timing booth. The return road is not a race track, so use a safe and prudent speed and don't drive like a jackass.
In our next installment, we'll take a few runs, and show how to read a timeslip. Stay tuned...