Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/127982
1999 Suzuki GSX1300R Hayabusa By Mark Hoyer peed freaks, get down on your knees (one puck at a time, naturally) and start praying in the cathedral of speed: You have a new higher being. Suzuki's GSXl300R Hayabusa is fast. We know this from spending the day riding it on the world--elass Circuit de Catalunya and its over-half-milelong front straight, as well as ripping along the motorway the next day at better than an 'indicated 300 kilometers per hour. And while the top-speed possibilities for a motorcycle with a claimed 172.6 hp and a shape sculpted for maximum aerodynamic efficiency are enticing, the speedometer is no'way to go about gathering data, especially on that end of the speed scale. What we feel fairly certain of, however, is that we have never ridden a street bike that pulls through the upper gears quite like the GSXI300R. The acceleration is mind-boggling - the Hayabusa spins through fifth like most bikes go through third. All this power coupled with the fact that we were riding on -stock tires should have made our time. at the track a hi'ghside-o-rama. ot that we didn't try, mind you, but the power delivery is nicely progressive as the revs build and there is little to get you in trouble except your own overexuberance, of which we've got plenty. Still, it's best to stuff it in deep, get it stopped, get it completely turned, and then pull the trigger. All this motive force comes from a big lump of motor, a 1298cc in-line four based in principal on the design of the GSX-R750's powerplant. As such, the cam chain is found on the right side of the engine, reducing bore pitch and helping to keep the intake ports as straight as possible. Four oil-cooled forged-aluminum pistons slide through their 63mm stroke in 81mm, SCEMplated aluminum bores, pushing and pulling combustion gases through very big, shim-under-bucket-aetuated valves (33mm in, 27.5 out) set at a narrow included angle of 28 degrees. The compression ratio is 11.0:1. Internal friction was reduced by eliminating a crankshaft journal (the l300R has five instead of the GSX-Rl1oo's six), which also helps make the crank stiffer, as does the larger journal diameter (4Omm vs. 36mm). All the better to stand up to the hefty twisting forces. An important addition to the l3ooR's powerplant is the gear-driven counterbalancer, allowing rigid mounting of the,powerplant in the twin-spar aluminum frame (a frame 15 percent more rigid than the GSX-R750's) without excessive vibration spoiling the ride. Still, you do get mild high-frequency vibes through the bars and pegs, d.espite the big rubber loaves on the pegs and the rubber-isolated bars. S (Above) Suzuki's goal for the Hayabusa was simple: Build the most powerful production bike in the world. They called it "Ultimate Sport." (Left) The unusual shape of the GSX1300R is a result of trying to achieve maximum aerodynamic efficiency. The windscreen is swept well back, interfering with the line of sight to the unique, stepper-motor-driven gauges. These gauges calibrate themselves every time you start the bike, cycling through their full range before resting on their zero points. 14 The electronic fuel-injection - featuring 46mm throttle bodies - and enginemanagement systems are based on those of the GSX-R750 and TL models, but are slightly more complicated in that they use a more frequently updating eightpole crankshaft trigger (the other models use four poles). The electronic control module does a lot of work, monitoring engine speed, vehicle speed, atmospheric pressure, throttle posi tion, camshaft position and more. Using this information, it controls injection for each cylinder's optimum performance - independently and sequentially - based on eight maps, then fine-tunes itself with infor• mation from the battery of sensors. Of the eight maps for each cylinder, four are for use in the low-rpm mode and four in the high-rpm mode. Similarly, the ignition has many maps, one for the two outer cylinders and another for the two inner ones, as well as distinct maps for each gear. Should there be a malfunction, the LCD on the instrument cluster that is usually a clock will say "Fl" and an LED to the right will flash or remain on. Then, by connecting a service check switch to the wiring harness, the LCD will display a code that indicates which I . component malfunctioned. 1 In any case, there's a lot happening to ) ensure smooth running and efficient power production, and the long and short of it is that the engine ran without fault from letting out the clutch in first gear to near top speed, save for some abruptness when getting back on the throttle after slowing for a comer, particularly noticeable on the street portion of our ride. Otherwise, the Hayabusa just makes power, Jots and lots of power. Suzuki tells us that in addition to the fact that there are 172.6 ponies (at 9800 rpm) on tap at the countershaft, the Hayabusa (it's a Japanese peregrine falcon that hunts small animals and other birds. Hunts other birds... Get it?) puts out tiresmoking 102 ft.-lbs. of twist at 7000 rpm. All this power and our Euro-spec test bikes were equipped with both air injec-