Nine Second Street Bike Part 3
We continue with Part 3 of our story on getting a streetbike to run a nine second quarter mile time at the dragstrip. The trusty Motoaus Hayabusa finally gets the job done in our third and last installment.
Well a whole lot of time has passed since Part 2 of this story, but finally we got it together to get to Part 3. We left off in Part 2 needing to get an ANDRA licence in order to be able to run in the nine second zone, due to their rules requiring this.
So first stop, off to the doctors for a medical for Bec, then forms filled and money sent, 4 days later, she was a licenced ANDRA rider. This is a fairly expensive process, the medical, licence, log book, and associated fees are over $500.00. But without it, you are not allowed to run quicker than 10.00 seconds at an ANDRA sanctioned event on a motorcycle.
With your licence you also need a log book for the bike you are going to race, and the bike then has to be “teched” (Technical Inspection). This is to ensure the bike meets the basic requirements for drag racing. In our case we had to add a “lanyard” supplied by Cyanide Racing, which is an engine kill device that you attach via a stretchy cable to yourself. Should you unfortunately part company with your bike for whatever unforseen reason, the plug is pulled, engine stops!
Since the last time we ran the bike, we fitted a shift light -more on this later- and a new Shinko USoft tyre. Fearing that the new tyre may expose the limits of the stock clutch springs, slightly heavier ones were installed.
With this all done, we were ready for the Wolf Racing sponsored Sportsbike Shootout at Willowbank Raceway, but the weather demons arrived, and the meeting was cancelled due to rain. We were keen to give the bike a run, so we headed out to a “Bracket” meeting a few weeks later.
Well the results weren’t what we’d hoped for at all, the combination of the new heavier clutch, and super sticky Shinko tyre, meant all the passes resulted in either leaving with too little revs, or a wheelie off the line. When drag racing a street bike, the wheelie is the one thing that can kill your times dead, if you back the throttle off even a little, the time is ruined. Those tenths of a second all add up! We left the meeting disappointed, Bec having managed to run only marginally better than her last effort, with a 9.85 best.
We tried again a few weeks later at a Saturday evening test and tune meeting, this time the clutch was put back to stock in an effort to make it launch easily. The launching seemed better, but the bike still hooked too hard, lifting the front if any really hard starts were tried. However, in spite of the better starts, the times weren’t any better, the mph strangely lower. Bec was quizzed about this, and seemed to think the bike wasn’t pulling very hard in higher gears. Our efforts were again cut short by a car racer oiling down the entire quarter mile, and causing an hour delay to the meeting which ended with out any more runs. Best for this meeting was 9.83, barely faster than six months ago!
After the meeting, when checking the bike over, it was noticed the shift light was acting strangely, appearing to reset itself randomly. Further checking revealed it was in fact faulty, and removed pending replacement. It appears the light would randomly activate during each run, causing our highly trained test pilot 😉 to shift up, whether the bike was at five thousand revs or ten!
Finally the next Sportsbike Shootout rolled around, weather fine. Clutch remained standard, shift light removed, and rear tyre pressure increased to 32lbs in an effort to slightly reduce traction, and prevent the dreaded “off the line” wheelies. The first few runs showed things were looking better, a couple of 9.9s, but still lifting the front on clutch release. The weather was ideal, not too hot, low humidity, and a warm sticky track.
Tyre pressure was raised even further, and burnouts were deemed unnecessary. Next run showed immediate improvement, dropping to its best yet – 9.73. This was followed by a -“missed shift” -10 second pass, another 9.7, then a -“hit the limiter”- in 1st 9.9. By now Bec was feeling comfortable on the bike, not having ridden if for a few months, and decided to pair up against another Hayabusa racer for a fun “grudge” race.
The extra incentive provided was enough to get her to hold the throttle open just that bit more, and the bike shot to its best ever 9.61 seconds, with a very nice 1.55 sec 60 foot time. There was enough time to try a few more small adjustments, with tyre pressure and burnouts. The next few runs produced another 9.6 (9.69) and 3 more 9.7s. Then it ran out of fuel! By the time this oversight was fixed, time was running out, and we called it a day.
The results were a longer time coming than we’d hoped, and although a 9.59 would have been nice, well take the 9.61 @145 mph and leave it there.
Bike setup in the end to run this – Stock 2000 model Hayabusa with 33,000 kms on the clock, lowering links on rear suspension, front forks pulled down with strap, Yoshimura exhaust cans, and the back torque limiter in the clutch welded. Rear tyre was a Shinko 190/55 Ultrasoft. The biggest components on the day, good weather, with nice air quality, and a light and reasonably skilled rider.
Fitting a 4 into 1, and a Power commander with a dyno tune, along with other assorted Hayabusa tricks like modifying the airbox, pair valve removal, and further gearing changes, would most likely see the bike into the 9.5s or 4s.
The Test and Tunes, and bike only meets, are held at various tracks around the country, if you haven’t had a run down the quarter mile on your bike, you should give it a try. Links to tracks are below.
There’s lots of fast streetbikes around, if you have one and wish to tell us and others about it, please join our forum and brag away. Also any questions about – or criticisms of- our story, post them there!
Other Drag Bike stuff is HERE