Drag strip

i'm thinking about taking the bike out to a drag strip to see how it runs before changing my exhaust and tires. i'll take it back after the change, and compare the results to see what performance changes occurred (if any).
does anyone have any tips on how to get the most out of a trip to the strip? maybe some suggestions on how to get an optimal run? i'm really excited about doing this, and would like to move on to a full track day some time after.
thanks for everyone's help!

:rockon: I got this from part of an article from sportrider magazine...... Preparing for the strip

Setting up a bike for the drag strip is pretty easy. You replace ethylene glycol coolant with water and put gas in the tank, oil in the engine, and air in the tires (oh, about 20 to 22 pounds or so in the rear). If you want to lower your bike, drop the triple clamp on the fork stanchions but make sure the front wheel or fender doesn't touch the radiator. Lowering the rear is more complicated. If your bike's shock has ride height adjustment, use that. Otherwise, lightening up on the preload will help some. Next, you need to rig a tether to kill your engine should you be unfortunate enough to fall off at speed. Companies such as Schultz Race Products (941/694-1919) sell trick kill switches that you splice into your wiring harness. Or you can choose the simple route of mounting the lanyard to your stock engine cut off switch with a self-tapping screw.

You'll need to prepare yourself also. Although rules vary with the track or organization you visit, the basics include: a full face SNELL 90 or 95 helmet (with a visor), a leather jacket and pants, sturdy gloves, and boots that cover your ankles. Don't worry if you don't have all this stuff, you won't have to spend a bundle. You can rent riding gear at select events. Vanson Leathers (508/678-2000), for example, will rent suits at most ADBS, AHDRA, AMA/Prostar events in 2000, plus three IDBA events.

Preparing your mind

When the time comes to make your first run, you'll notice that everything moves pretty quickly once you get out of the staging lanes. So, it helps to have an idea of what's going to happen before the tree lights up.

The first area you'll pass is the burnout box. Since this section is usually hosed down to assist breaking the rear tire free from the pavement, avoid the water to keep your front tire dry. Although doing a burnout isn't necessary on your first run (but it's fun and you will need to learn how to as you improve), the proper technique requires that you back your rear tire into the water, clamp down on the front brake, bring the revs to 7000 or so, and dump the clutch. Once the tire is spinning you can modulate its speed with the throttle. When the tire's good'n'smokey, ease up on the front brake and let the bike spin forward onto dry pavement before you pull in the clutch.


Finding the friction zone (the point where the clutch begins to engage) and backing off until the clutch disengages-and no more-will shorten your reaction times and ease the control of wheelies off the line.
Forget what you were told in your MSF class. Throttle control in drag racing means getting wide open as soon as possible. So, get your wrist up to make it easier. Note the tether connected to the kill switch.

Next, you'll want to do a "dry hop," which is essentially a short, practice launch. Bring your engine up to launch rpm and let'er rip-for about five feet. Did your engine start to bog or did your tank come up to greet you? Depending, you may need to adjust your launch rpm.

Now comes the fun part. Push your bike to just shy of the white line that marks the starting point. Ease the clutch out until it begins to engage and deliver power to the rear wheel, then pull it back in slightly until the engine spins freely again. Raise the rpms to your launch rpm. Using your toes push the bike forward until the pre-stage light on the Christmas tree comes on. Wait until your opponent is also pre-staged. Check that you are still at your launch rpm then push the bike forward until the stage light illuminates-and no further. Once both riders have staged, the tree could light up at any time. Be ready.

On the launch pad

To keep the front-end down, the proper position for the launch has as much of the rider's weight forward as possible. Press your, er, crotch right up against the tank. Your upper body should be as low and forward as possible, too. Gadson, my coach for my first weekend of drag racing, said one of the most common novice mistakes is to sit too upright at the start of a race. Not only does the rider not get enough weight forward, but also the launch is complicated by having to lower down into a tuck while concentrating on the clutch. While most drag racers start with both feet on the ground, a few (myself included) prefer to keep the left foot on the peg to be ready for shifting. What is compromised with this technique, however, is stability on the line. Get a little tilted and the bike must also be straightened while the clutch is modulated.



Good form-if not speed. My pelvis is all the way forward against the tank. My head is low and forward, placing as much weight as possible on the front wheel.
The clutch is where the real action occurs. There are two routes to blowing the launch. First, the popular letting the clutch out too quickly and lofting the front wheel costs time because backing out of the clutch long enough to get the front-end back down kills the drive. The second blown launch is caused by slipping the clutch too much and not getting the power down soon enough. On the razor's edge between these two options lies the ideal launch. Finding the right launch rpm will help you to ride the edge without getting cut.

Don't get too greedy too fast, however. Begin with a conservative 3000 rpm and listen to the motor leaving the line. Does the load pull the revs down? Build the rpm 1000 at a time for each successive pass. Once the rpms don't drop on the launch, the timing slips come into play. Keep increasing the rpm in 500 rpm increments to see how the 60 foot times are affected. If the front starts to lift or the 60 foot times begin to suffer because of the excessive clutch slippage required to keep the front down, back off to the rpm that resulted in the best 60 foot time. Good notes will pay off.

Once the stage light on both lanes are illuminated, the three yellow lights could start at any time. When running a street tree, 0.500 seconds separates the lighting of the yellow bulbs. The pros get all three yellows on at once for only 0.400 seconds. Since most people with good reactions can respond to a signal in about 0.400 seconds, the secret to a good reaction time is to start releasing the clutch as soon as the last yellow light comes on. If you anticipate the light, you may scratch, and the tree's red bulb will signal that your run doesn't count. Since Reaction Times are measured from the final yellow light, responding correctly will move you one step closer to the much sought after perfect Reaction Time-0.501 seconds (or 0.401 for pro lights). If you see the green and you're not already moving, you're toast!


Use the practice runs and the 60 foot times on the timing slips to determine the proper launch rpm. Don't spend too much time idling the engine while in the staging lanes. A hot engine will generate less power.
Since you need to ease from pre-staging to staging without disrupting your readiness for the launch, use your toes to creep forward until the staging light comes on. Drag racing boots with their supple soles help immensely. Riders who like to start with their left foot on the peg should try bracing the right peg against their calf to help steady the bike on the line.
The standings during qualifying are posted near the staging lanes. Here Gadson points out the gap between my times and competitive ones: "Up there at the top, that's me. And way down here at the bottom, that would be you."

Get those shifts down

Rocketing away from the line in first gear gives you almost no time to prepare for the shift. Preloading the shifter by lifting up with your toe until the shifter stops will help a bit. Since the transmission is under a tremendous load, the bike won't jump out of gear. Shifting is then accomplished by either partially closing the throttle for an instant or keeping the throttle open and fanning the clutch. Both these techniques unload the cogs briefly, allowing the shift to occur. Once in the new gear, release and preload the shifter again. One caution about clutching with the throttle wide open: If the clutch is disengaged for more than an instant, the revs will skyrocket, causing big squirms or wheelies when the clutch re-engages. Fanning the clutch entails, in effect, slapping the end of the clutch lever with your hand to keep the clutch disengaged for a short time. Another method of speeding the clutch is to pull in on the lever (a quarter or half inch should do it) enough to unload the tranny for the shift.

Although the shift from first to second is crucial, the other gears are no less important. Keep a careful eye on the tachometer. Tapping the rev limiter will hurt your ET in a big way. Short shifting before peak power will hurt you also, but not as badly. If you must err, be sure to do it on the short shifting side.

Putting it all together



Anatomy of a (losing) timing slip.
After completing your first run, you may be surprised that what seemed like an instant was closer to 15 seconds. Stop at the timing slip booth to get your record of the run. Next-after the adrenaline rush has subsided-find a quiet place to sit and go over the run in your head. Break it down into sections. How was your launch? Did all the shifts go well? Did you realize you were dragging your right foot until you shifted to second? Write it all down. As you begin to get the hang of this drag racing thing, you'll find timing slips and your notes invaluable in helping you dial in personal best times or, as with ET racing, consistent reproducible runs. Look around in the staging lanes. Many racers will sit with their eyes closed, not in prayer, but to visualize their next run. Beginning racers will benefit from focusing on one aspect of their technique and visualizing it before the run. Afterwards, it's back to the books. Did what you tried in the run have the desired result? After a while, you'll have enough notes to construct a perfect run on paper and a goal to strive towards on every trip down the strip.

Holy giant post batman!

I went to an 1/8 mile track a few weeks ago. It was a run what ya brung night. $5 a run, all you need is a helmet and jacket.

Best advice, learn how to launch. 7-8k rpm, and get the clutch out fairly quick. Stock gearing is far too high to get a good launch, you either smoke the clutch or bog the engine. I was running 7.95avg for the 1/8 mile.

MRGM said:

Holy giant post batman!

I went to an 1/8 mile track a few weeks ago. It was a run what ya brung night. $5 a run, all you need is a helmet and jacket.

Best advice, learn how to launch. 7-8k rpm, and get the clutch out fairly quick. Stock gearing is far too high to get a good launch, you either smoke the clutch or bog the engine. I was running 7.95avg for the 1/8 mile.

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$5 a RUN?

our run what ya brung night is like $15 run as much as you can......

madmanmaigret said:

$5 a RUN?

our run what ya brung night is like $15 run as much as you can......

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Let me guess, you ran 3 times?

Wavex said:

Let me guess, you ran 3 times?

Click to expand...

I think it was around 11 or 12 times. Then someone snapped an axle and spit transmission fluid all over the track and we left. (obviously it was fairly dead that day)

But I have been there where some guys showed up, and it started to lightning (Florida Summer....every day) and they shut the track down so he never even got to run. You win some you lose some.

Vegasrider had a post a while back with an SV650 comparison:

http://www.600riders.com/forum/fz6-general-discussion/13361-vegasrider-vs-sv650-lvms-dragstrip.html



Dave

The place I sent had a few thousand people show up... though not everyone races. They can charge $5 a run and still have a huge line.

good luck the best i did was 8.4 in the 1/8th with a .7 rt, the only think i had done is a k&n filter. i went on a bald tire too didn't wanna tear up a fresh one