Comparison Test - 2008 Kawasaki ZX-14 And Suzuki GSX1300R Hayabusa - Big Numbers

Either bike offers more than enough power to get you into plenty of trouble-if not jail-on the street, but each delivers that power in a different manner. The Suzuki's dual throttle valves and dual injectors give cleaner response than the Kawasaki's dual-throttle-valve/single-injector setup. Just as on the similarly equipped GSX-Rs, the Hayabusa's off/on throttle is smooth at any rpm. The ZX-14 has slightly more engine braking to begin with, but cracking the throttle open midcorner slows the bike even more before power comes on with a jolt. Excessive driveline lash makes the situation worse, turning almost every apex into a heart-in-throat moment. Surprisingly the Hayabusa's uneven torque curve leaves it feeling underpowered in many instances, and many slower turns require first gear for a clean exit. The Kawasaki's smoother graph results in a more useful powerband, and the ZX pulls cleanly and strongly from even walking speed in second gear. Although our testers agreed that both bikes had way more than enough power, they were divided on which motor was more user-friendly.

Analog instrumentation is attractive, but the speedos pack a lot of numbers into a small space, making them difficult to read-especially when the needles move as fast as they do on these bikes. The ZX-14's black-on-white dials are clearer than the Hayabusa's during the day, but both are almost impossible to read at night with orange backlighting. LCD panels show gear position, clock and tripmeters; the Kawasaki adds fuel economy info as well as fuel and temperature bar-graph gauges. The Hayabusa's mirrors are old-school and require you to turn your head to see them; the ZX-14's mirrors are wide and farther forward for an easy, clear view of what's behind.

Thanks to stricter emissions regulations for 2008, the ZX-14 and Hayabusa porked out in overall weight with heavier exhaust systems that have catalyzers in their collectors. The Kawasaki is four pounds heavier than the '06 model, the Suzuki a whopping 20 pounds more than the last version we tested in 2005.

Both bikes' front ends are similar to their literbike counterparts, with 43mm Kayaba inverted forks and radial-mount, four-pot calipers. Beefier (and in the Hayabusa's case, more stylized) wheels deal with the big bikes' weight. The Kawasaki's (left) four-pad Nissin calipers (the ZX-10R uses Tokico units) and petal rotors are crisper and give better feedback than the Suzuki's (right) two-pad calipers.

While at low speeds the 'Busa feels the heavier of this pair, once underway it seems to shed its weight more than the ZX-14 does, with easy, neutral steering. As with the more recent GSX-R models, which have also filled out over the years, the Suzuki acts like a much lighter bike at anything above walking speeds. The Kawasaki in contrast is a bit lumbering and calls for some pressure on the inside bar to maintain a turn. Another plus in the Suzuki column is the tires: It's shod with Bridgestone's latest BT-015s, which offer more grip than the one-generation-older BT-014s on the ZX-14 and may contribute to the Suzuki's lighter steering. The Hayabusa, with more nimble handling (again, it's a relative term, like saying an SUV is more nimble than a school bus) and firmer suspension, is easier to ride quickly in the twisties despite its wooden brakes. Given 170 horsepower to fling around in anger we'd prefer it be housed in the Suzuki's chassis.

You'll note that we've made no mention of the Suzuki's S-DMS mode switch, which-just like on the GSX-R1000-limits power in the B and C modes. In all honesty we don't see the point in the different modes. When you're on a tight, dirty goat path or riding in the rain it doesn't make sense to change what should be familiar factors like engine power and response; in tricky conditions it's far better to deal with known quantities. Mode switch or no mode switch, if you're not prepared to deal with the Hayabusa's full power then perhaps you'd be better off with a different bike.

The ZX-14's more upright riding position is definitely noticeable on the road, and its slimmer seat makes reaching the ground easier even though both bikes' seat heights are about the same. Both bikes have severely angled-back clip-ons to close up the riding position, the Hayabusa's to the point that some riders' wrists cramp up.

Not only do these two hyperbikes have more torque than current literbikes, their gear ratios are more spread out and more appropriate for real-world street riding. That equates to more thrust at the rear wheel in the lower gears; in first gear the Hayabusa and ZX-14 pound out almost 1000 pounds; the typical literbike peaks at about 750. The Kawasaki has a major-overdrive sixth gear and a theoretical top speed of 207 mph; the Suzuki maxes out at a theoretical 203 mph.

Big numbers: The Kawasaki's and Suzuki's graphs criss-cross at lower revs until the Suzuki gains an advantage at the top end. Maximum rpm is about the same for both bikes, the Kawasaki just missing the final, 11,000-rpm data point and the Suzuki going a hair beyond. The most powerful current literbike is the GSX-R at 158.2 horsepower (boring!), and the sportbike with the highest torque we've tested recently is the Ducati 1098, with 77.5 ft-lb (yawn).

With Los Angeles County Raceway now a gravel pit and the remaining area dragstrips ridiculously expensive to test at, we used our Stalker radar gun at Honda's Proving Center of California to record quarter-mile runs. We've been anticipating this move for more than a year and ran extensive comparison tests between the gun and dragstrip lights-it's incredibly accurate. Here the ZX-14 and Hayabusa run dead even until the very top end, where the Suzuki ekes out a small advantage. The time gained compared with the typical literbike (the GSX-R1000 is shown here for comparison) is in the first few seconds, where these bikes have more thrust yet are less wheelie-prone through first gear.

The Suzuki has an advantage in top-gear roll-ons, mostly due to slightly shorter gearing and a bit more torque at the right revs. These bikes have more torque and thrust at lower rpm than the literbikes but can't muster up the roll-on numbers to reflect that-most likely their weight plays a factor here. The quickest literbike numbers we saw last year were from the ZX-10R, almost identical to the ZX-14's and shown here for comparison.

Our performance testing revealed some interesting details. Both bikes are, as their manufacturers claim, limited to a top speed of approximately 186 mph. The Suzuki hits a rev limiter and feels as if it can go faster than the 184.9 mph we recorded, and the Kawasaki ran out of steam at 184.0 mph. De-restriction is practically a moot point now: If you know the bike you're building is to be limited in top speed it makes sense to design around that parameter. Thus the Hayabusa has slightly shorter final gearing this year, and Kawasaki concentrated on enhancing bottom-end and midrange torque for the new model rather than top-end horsepower.

In acceleration testing the pair logged quarter-mile times just 0.05 seconds apart, with the Suzuki having the upper hand. The ZX-14 leaves the line quicker and more consistently thanks to an easily modulated clutch (just as on the brake side, the Kawasaki has a radial-pump clutch master cylinder whereas the Suzuki has a standard unit) and a flatter torque curve. The Hayabusa, with an abruptly engaging clutch and lumpier torque curve, is more difficult to launch but makes up time at the far end of the strip.

Add everything up and the Suzuki comes out on top here by a small-but appreciable-margin. That said, it would pay to think carefully about how you intend to use your hyperbike before making your own decision. The Hayabusa is the better sporting package and has more peak horsepower; the ZX-14 has better bottom-end torque and is a more amenable companion for riding long distances. We suspect that not many of these bikes will remain stock for long, and that's another consideration: Some new pads could perk up the Suzuki's brakes, and a tire swap may very well lighten the Kawasaki's steering. The aftermarket is ready to add however much power you think you need to either bike, whether it's a few or a few hundred horsepower. And finally, style is an all-important consideration-maybe the only consideration-with these two bikes. That is a factor only you can put a number on.