Fans of the Suzuki Hayabusa have no doubt been frustrated by our recent AMA/Prostar drag bike profiles, which so far have focused on newer, fresher machinery like Rickey Gadson's Kawasaki ZX-14 Super Street racer ("Big Guns," page 60, SSB June 2006) and Kent Stotz's turbocharged Honda CBR1000RR Pro Street machine ("Not-Quite-So-Big Red," page 66, SSB Sept. 2006). Our bias toward these other bikes is just another example of the old-news 'Busa being overshadowed by this year's new hotness, right?
Forget magazines for a moment, though; the one place where the top dog Hayabusa hasn't been overlooked is the one place that really matters-on the drag strip. While the headlines have been hogged by the King Kong-strong ZX-14 and Stotz's over-achieving liter bike, it's been a different story at the track. The top spot on the podium, more often than not, has been held down by a Hayabusa, specifically the 'Busas built by Suzuki super-tuner Barry Henson at Velocity Racing. Proof: This story went to press immediately following the Norwalk round of the AMA/Prostar championship, where Henson's 'Busas ruled the roost and won both the Super Street and Pro Street racing categories. Despite fierce new competition in 2006, the well-developed Hayabusa is proving to be anything but washed up.
With the release this year of the Kawasaki ZX-14, which appears on paper to be the biggest threat to the 'Busa's drag race dominance since the big Suzuki first appeared in 1999, we all knew this year would see a battle of the titans on the showroom floor and at the racetrack both. And at the beginning of the year it looked like Kawasaki had the upper hand. Kawasaki sent three different ZX-14s to the opening round of the 2006 AMA/Prostar series in Valdosta, Georgia (a non-points exhibition race), while Suzuki didn't even bother preparing a Hayabusa to run in the newly created and high-profile Super Street class. When that first weekend wound down, Kawasaki left Valdosta with Rickey Gadson taking the win in Super Street on his Coby Adams-prepped ZX-14 and setting the class record at 8.51 seconds and 175.09 mph. American Suzuki race department officials were present at that first event in Valdosta, and they didn't take the Kawasaki threat lightly. Suzuki turned to Barry Henson of Velocity Racing and asked him to put together a new Super Street race bike in only four weeks and have it ready to compete at the next round.
Henson and his Velocity crew know fast 'Busas-Velocity-built (and often, Henson-ridden) Hayabusas have pretty much owned the premier Pro Street (formerly Streetbike Shootout) class for years now, so building a competitive Super Street racer to take on Gadson's ZX-14 wouldn't be much of a stretch. That's not to say that it would be easy, exactly-the Super Street class has a different rule structure than the Pro Street class and its own unique challenges to going fast. The idea behind Super Street is to give racers (and fans) another streetbike-based racing class that wasn't as expensive as Pro Street, where a competitive bike can cost as much as $60,000. The Super Street class was designed to allow real streetbikes (nitrous and turbo both) to compete head-to-head, with a more restrictive state of tune to be easier on the bike owner's credit cards. To help control costs, turbocharged Super Street bikes are limited to a 54mm inlet diameter (vs. 62.5mm in Pro Street), and they are not allowed to use multistage boost controllers. For boost control, they are limited to just two stages (with only one tied to spring pressure). Also, they are not allowed to use water injection or intercooling of the intake charge. Clutches are also slightly different in this class, with no multistage lock-ups allowed. Instead these bikes use just a two-stage lock-up, which forces the rider to carefully launch the 64-inch-wheelbase bikes to prevent wheelies.
Always the racer, Henson would not reveal the boost settings used for the Super Street application, but reliable sources peg it at around 5-7psi at launch and 15psi in the second stage. Henson did say that they use a fully prepped turbo engine as a base in order to make as much power as possible at low boost. That means a full turbo-ported head from Ward Performance, JE-forged pistons, Falicon knife-edged rods, Ward Performance cams and double-sprung valves, and a rpm locker clutch on top of an OEM clutch basket.
Another difference in the Super Street class is the mandated use of ZR-rated DOT street tires. The most popular tire by far is the Pirelli Dragon Super Corsa Pro. The Super Street class also requires the use of all stock bodywork and the original fuel tank, with the exception being the tail section-this piece is allowed to be replaced with a slightly longer aftermarket piece (like the one from Catalyst Composites that Velocity uses) to cover the extended swingarm. The class does allow the use of limited electronic data logging. With only three channels allowed (O2, boost and rpm), data logging can be easily handled by a typical Wideband Commander from Dynojet, which helps keep costs down. Velocity, however, uses an Innovative-brand boost controller to collect data for their setup.
True to form, Henson had the new Hayabusa Super Street race bike ready for battle at the second round in Commerce, Georgia, in April, where the machine made its debut. By the end of the qualifying sessions the Velocity Suzuki, with Mike Slowe at the controls, had already broken the class record with a top qualifying spot at 8.312 seconds and 176.02 mph, compared to a best pass that day by Gadson's Kawasaki of just 8.519 seconds at 169.95 mph (landing him in fourth place). At the end of the final eliminations the Hayabusa remained on top, Slowe winning the event with a final pass of 8.458 seconds at 176.57 mph (Gadson was eliminated in an earlier round due to a nitrous malfunction on his Kawi). A review of the weekend for the new Suzuki saw a string of quick passes: 8.352, 8.360, 8.387, 8.395 and 8.458. Velocity clearly did their homework, and even with the short preparation time, they brought a dialed-in package to the track.
The Velocity Racing Hayabusa continues its success through the season. At press time Slowe sat on top of the Super Street points standings in first place, with Gadson and his ZX-14 two spots back in third, and the 'Busa continues to lay down quick times with the quickest pass in Norwalk dispatched in just 8.399 seconds. The paddock is thick with rumors of what will be Kawasaki's next volley-suggestions, even, that Team Green was preparing a new turbo version of the ZX-14 to put them back in the hunt for the Super Street class title. For now, however, it is clear that the ZX-14 isn't as much of a threat to the well-developed and race-proven Hayabusa in actual drag strip competition as many feared after its stellar debut. Though it may be a bit long in tooth, the old 'Busa is not ready to roll over just yet. In the hands of top tuners like Velocity Racing, the Hayabusa still has the right stuff to win at the national level.
Spaz Racing's 188-horsepower Hayabusa hop-up kit will give you all you need to put down ZX-14s on the street
Even though it's intended as a "budget" big-bike racing class, a competitive turbo setup capable of producing upward of 300hp that is required for Super Street success will still cost you at least $10K. But what about all you street-bound Hayabusa riders who are not blessed with a pocket full of dead Presidents, but are still wondering how to upgrade your old steed in order to keep up with the admittedly stronger Kawasaki ZX-14 on the streets?
Consider sending your bike off to John Springer at Spaz Racing (www.spazracing.com) in Springville, Iowa, which has developed a very economical, $1,500 turn-key tuning package for the Hayabusa that pretty much guarantees that your buddy's brand-new Kawasaki ZX-14 won't wax you on the street.
For optimum results, Spaz Racing already assumes you have a full aftermarket exhaust (the Brock's Performance Street Smart System or Ti- Force Sumo are highly recommended) as well as a Dynojet PowerCommander and a modified airbox with a high flow air filter. Given that starting point, Spaz's first step is to pull the head and mill it to improve flow. The stock base gasket is then removed, which bumps the compression up to 12.5:1. Compression is power, Spaz says, and the Hayabusa responds well to the added static cylinder pressure, which is why this modification is made.
Next Spaz bins the stock exhaust cam and replaces it with a stock Hayabusa intake cam. They also add APE slotted cam sprockets that allow complete adjustment of the lobe centers. Spaz would not reveal the exact cam timing used with this kit, but he did say it was not as far from stock as many people think. In order to keep the valves from floating at high rpms, Spaz also installs aftermarket APE valve springs. Even though the ECU and stock rev limit is not raised, aftermarket valve springs are employed to decrease the chance of float. Everyone has their preference on engine oils, and Spaz is no different: For best results with these mods, Motorex engine oil in standard viscosity of 5W-40 is suggested. Unlike some other tuners who resort to ultra-thin engine oil to make power, Spaz prefers the added longevity of normal weight oil.
After everything is buttoned up, the tank is filled with VP Racing MR9 gas, and the bike is strapped to the shop's Dynojet 250i dyno for final tuning-included in the cost of the kit. The final results? How about 188hp and 106ft/lbs of torque, all in a very streetable package that is capable of keeping ahead of any mildly tuned ZX-14. The drive-in, drive-out service includes all the parts and modifications mentioned-a complete, turn-key job for $1,500, a bang-for-the-buck ratio that's hard to beat.f,,--Don Smith