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Topic ClosedHow to Slam and Prep a Busa... Part 1 - Event Date: January/01/1900

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Direct Link To This Post Calendar Event: How to Slam and Prep a Busa... Part 1
    Posted: January/21/2003 at 6:14pm

How to Slam and Prep a ‘Busa… Part 1

Well, you’ve finally gone and done it! After carefully investigating all of your options, you’ve made the obvious choice… the purchase of shiny new Suzuki GSX1300R Hayabusa. You realize that you now own the quickest and fastest production machine ever to be unleashed on the speed-hungry public, but where do you go to enjoy all of this performance? Doubling (or tripling!) the national speed limit is severely frowned upon by officer Fife and his associates. Road rage can now be defined as realizing that the folks setting the speed limits in your area, definitely do not own a late model sportbike, much less 1300 cc’s of ground pounding Busa. These bikes are obscene; they make highly modified bikes of just a few years back appear slow or just plain obsolete. Where to go? The answer is obvious…a trip to your local drag strip.

The Hayabusa has real 9-second potential, but not in stock form.

And once slammed, a ‘Busa not only performs, it just plain looks better!


A small entry fee and some basic safety equipment are all that is required to legally attempt to tame your new beast. No speed limit and a significantly-reduced chance of scratching your new steed compared to having to deal with curves?! These factors, combined with motorcycle drag racings unmatched safety record, have been making tune and test sessions a very busy place for street bikes up and down the Eastern-half of the United States for the past several years.

But wait… now you have another dilemma. You have been a spectator at some of these sessions and witnessed some of these bikes running well off of the “magazine times.” NINE-second bikes logging TEN-second quarter miles, or even Elevens?! You could never look so foolish; you are sporting the Big Johnson of street bikes! Your buddies would ride you like a mechanical bull at the sight of a sub-par time slip…Oh my, the pressure!

Relax; this is where I can help. Even though it may not be proper P-R for a factory-assisted Suzuki rider, I am going to let you in on a little secret; your average guy can’t run nine-anything on a bone stock Hayabusa! The magazine boys use “corrected times” to obtain their numbers in addition to as many passes as it takes, in a private setting, yet they can barely see a nine second pass. Never fear, there is a simple, and inexpensive solution for you. With minimal modifications to the bike, you can have your buddies wondering how you went so much FASTER than the magazine test pilots. These changes do nothing more than prepare the bike for the drag strip without detracting from the streetability whatsoever. The object is to promote smooth, wheelie free operation in the first 330-feet, not just the first 60-feet. The 60-foot is important, but a good 60-foot combined with wheelie-fighting after that will not get the job done. From the 330-foot on, the gentlemen from Japan take over; all you have to do is hit the shift points.

The first modification is to install a Brock Davidson Enterprises Clutch Conversion Kit. The purpose of the kit is to disable the back torque limiting slipper assembly that comes with the bike. The slipper assembly works fine for general-purpose riding, but causes an abrupt “hammering” effect while attempting to launch the bike from a dead stop.

This hammering not only makes a smooth drag style launch nearly impossible, but it has also been blamed on premature wear to the clutch basket and surrounding components and even drive chain breakage, under this type of use. Once the clutch conversion is installed, a slight increase in lever pressure is noticed in addition to a bit more rear wheel chirp during down shifts.


9-second ingredients: Dog bones, Sprocket,
Clutch kit, Tie-down, and one ‘Busa.


Simply stated, the clutch conversion does nothing more than allow the Busa clutch to now function like all of the other fantastic Suzuki clutches we have become accustomed to. The kit comes with complete, easy to follow instructions and installs in less than an hour. Standard hand tools are required, in addition to an impact gun to remove the clutch hub nut. I only use Genuine Suzuki components for my modifications. Don‘t be fooled by imitations or other methods. Who better than a rider to correct issues of rideability?

Now that the clutch operates smoothly enough to get you off of the line, the focus turns to controlling wheelies. As a general rule: a one-tenth per second decrease in quarter mile elapsed time is possible for each inch that the bike is lowered. The Busa actually benefits more than this due to the relatively short (in the drag race world) wheelbase and abundance of torque and horsepower. The addition of Brock Davidson Enterprises Three-Hole Lowering Links or “dog bones,” as they have affectionately become known, handle the chores on the rear of the bike. Again, they come with complete assembly instructions and initially install in about 20 minutes; adjustments can be made in less than five. A rear stand and floor jack make installation and adjustment a snap. To confirm our general rule; we have noticed a one-tenth per second quarter mile elapsed time difference between position two and position three on the links. Besides, a slammed Busa looks far cooler than one that is up in the air.

The front of the bike is easily lowered with the addition of a Schnitz Racing Front End Lowering Strap. Be careful to route the strap under any wires or cables to prevent damage. I remove the cable anchor near the steering head to prevent chafing of the strap. I also install the latch side of the strap on the sprocket side of the bike. This is the proper position to pull the strap tight with your left hand while holding the front brake with your right hand and rocking the bike forward to compress the front forks. Be sure to cable tie the loose end of the strap to a secure spot on the chassis to prevent it from falling.

A rear stand and floor jack are necessary
for installation and adjustment of the
rear lowering kit


The final mod in this series is the addition of a 16-tooth front sprocket to replace the stock 17-tooth unit. This may sound a bit strange after all of the effort we have gone through to prevent wheelies, but there are several reasons for making this change. The first of which being the bike actually becomes EASIER to launch if the other mods are in place. With this sprocket installed, a rider can leave the line just above idle (around 2000 rpm) and gently release the clutch, while progressively screwing on the gas at the same time. This technique requires far less rider talent than a higher rpm launch and it helps prevent expensive burned up clutch plates as a result. The bike will accelerate harder down the track and cross the traps in fourth gear closer to red line. The only real disadvantage is that the speedometer will indicate about 10 mph faster than the bike is actually traveling. This additional “cushion” is not necessarily a bad thing on the street!

Well, there it is! A little cash, a little time and POOF!…. You suddenly deserve the respect associated with being the pilot of the World’s Fastest Production Motorcycle.

Once in place, the link can easily be adjusted by pulling the lower bolt and re-inserting it into one of the other two positions. As shown, bike is at lowest ride-height setting. Each position drops the rear one inch.

F.Y.I; Most Hayabusa’s set up this way in the hands of relatively competent riders (with the mirrors removed, the rear seat cowling in place and around 22 PSI in the rear tire), usually run in the 9.60 range (or better) at around 145mph in the quarter mile and low 6.20’s at 117mph in the 1/8 mile. Good 60-foots are in the mid 1.50’s. If your own progressive numbers aren’t this good, you must review the 330-foot times. If they aren’t in the 4.10-4.15 ranges, YOU need more practice! From an elapsed time standpoint, it is critical to have the throttle pinned and the clutch lever completely out before the first to second gear shift, in addition to pressing your ass firmly against the rear cowling from this point on. Remember…ALL of these bikes run the same; the elapsed times are up to you. Riders beware! If you aren’t accelerating hard on the front half of the track, you can’t MPH on the back half either.

Next time, fine-tuning a stock chassis and bolt-on performance modifications.


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