The recent Top Speed Challenge event that we hosted at the Maxton Monster Mile formed the perfect excuse to issue a little top-speed challenge to ourselves and see if we couldn't coax our Kawasaki ZX14 project bike to 200 mph on the East Coast Timing Association's standing-start, one-mile racecourse at Maxton. Even with such an aerodynamic and uberpowerful starting point as the 170 hp ZX14, we knew that breaking the double-ton barrier would be no easy prospect, but we figured that with a little help from the right tuners and aftermarket parts providers, even such an ambitious goal should be within reach.
The first call we made was to legendary Kawasaki tuner Rob Muzzy at Muzzys Performance Products in Bend, Oregon. No one knows better how to extract big power from Kawasakis than Muzzy, and his company offers the most complete collection of aftermarket performance parts for Kawasaki's top-dog Ninja available today. Muzzy kindly offered to set us up with one of his brand-new M10 Series 4-into-1 megaphone exhausts (the first one in the nation, actually), along with his dry nitrous oxide system, a combination capable of well beyond 200 hp to make hitting 200 mph on the ZX14 a realistic possibility. At the same time, we ordered up a Dynojet Power Commander III-USB that would allow us to optimize the fuel/air mixture for maximum performance, as well as a Timing Retard Eliminator (TRE) from Ivan's Performance Products to disable the digital skullduggery that neuters the ZX14's performance at low revs in the bottom four gears. Top AMA tuner Greg Moon of Moon's Super Cycle in Milwaukee, Wisconsin, was selected to assemble and tune the bike, drawing on his expert experience building up some of the Midwest's fastest nitrous drag bikes to ensure the maximum possible performance from our nitrous setup.
The Moon crew's first move was to strip off the stock exhaust and bolt up the gorgeous M10 system ($995.95) from Muzzys. Consisting of a stainless steel 4-into-1 header paired with a tapered, stainless-steel, GP-style, reverse-cone megaphone, the M10 mounts snugly against the swingarm on the right side for increased cornering clearance and also shaves off a significant 27 pounds compared to the stock 4-into-2 dual exhaust. Not only does the M10 offer GP styling, but it also provides a MotoGP-style exhaust note when that 1400cc of exhaust volume clears out through the single megaphone's open-core, race-style baffle. To enthusiasts, the system sounds awesome (your neighbors might not agree), but you might do well to insert earplugs if you're going to be riding the bike for anything much beyond a quarter-mile at a time.
Installing the freer-breathing M10 exhaust required some alterations to the fuel/air mixture, so Moon also lined in the Dynojet Power Commander III-USB ($339.95) adjustable fuel-injection module to allow him to optimize the air/fuel ratio for the new exhaust and soon-to-be-added nitrous system. Because the ZX14's fuel tank is located under the saddle and underseat space is at a premium, the PCIII-USB actually mounts inside the upper fairing on the ZX14. Once the module itself was located, the PCIII-USB's OE-style connectors mated to the stock ECU seamlessly without splicing or cutting, and the USB port connection lets you alter the map in minutes using a Windows-equipped laptop computer.
Moon also wired in a Timing Retard Eliminator ($70) from Ivan's Performance Products-consider this a mandatory modification to any ZX14. From the factory, the ZX14 suffers underwhelming performance at low revs in lower gears due to the part-throttle timing retardation programmed in to limit acceleration and ostensibly to keep less-experienced riders from landing on their heads if they whack the throttle too aggressively. A simple, inexpensive device that produces dramatic horsepower gains below 6000 rpm (just adding the TRE resulted in a 13-horsepower gain at 4000 rpm on our bike), the TRE tricks the ECU into thinking it is in sixth gear all the time, allowing the throttle plates to open at the sixth-gear rate (the fastest rate) in every gear and improving rideability by granting access to full timing at all times for improved throttle response and smoother power delivery. Like the PCIII-USB, Ivan's TRE is also a plug-in product that doesn't require any cutting or splicing of wires. The only disadvantage to installing the TRE on the ZX14 is that it makes the bike's factory gear indicator useless (this always displays a "6" after the TRE is installed).
Our last motor mod-and the most important one-was to install Muzzys' dry nitrous system ($499.95). Unlike other dry systems that spray the nitrous shot at a single point, the Muzzys system sprays directly over each inlet stack through drilled orifices in stainless runners for maximum effectiveness. Installation of the system was straightforward and simple. Unlike universal kits that need to be adapted to the bike, the Muzzys ZX14 kit is complete and includes every last necessary bracket and bit of hardware needed to button it up. The Muzzys kit comes with a one-pound nitrous bottle and mounts to attach that bottle to the rear subframe. A one-pound bottle is somewhat small, and when running the #30 jet (the kit also comes with #26 and #28 jets), the bottle would run empty in just 16-18 seconds on the dyno. As supplied, the Muzzys kit positions the bottle parallel to the subframe with the valve aimed toward the rear of the bike. Because the pickup tube is at the bottom of the bottle, and because we planned to spray for a sustained period over the mile-long Maxton course and wanted to ensure that we used every last ounce of nitrous on every run, we modified the mount to carry the bottle right-side up and roughly perpendicular to the subframe. That way, when the bike was accelerating, the nitrous was forced to the back of the bottle where the pickup tube was located.
Along with the dry nitrous system, Muzzys also supplied us with its ZX14 air shifter kit ($699.95), powered by the pressurized nitrous bottle (this can also be run on compressed air, if your bike isn't equipped with a nitrous system) for instant, clutchless, push-button upshifts. The air shifter uses Muzzys' own Digi-Kill power-interrupt (included) that, unlike analog kill boxes, interrupts fuel delivery instead of killing the ignition for much smoother power interruption and less chance of backfiring. In addition, the Muzzys Digi-Kill is unique in that it matches the kill time to coincide with the actual movement of the shift linkage, for absolutely seamless, worry-free upshifts. When used together as we did, both the nitrous system and air shifter are operated by a single toggle switch hung from the lower mount bolt on the clutch lever-flip the switch to arm the system, and the bike's start button becomes the nitrous button, while the horn button handles shifting duties.
Assembly was straightforward and simple. Muzzys supplied a fuel-injection map designed specifically for this exhaust/nitrous combination, and that was the one Moon used with minor adjustments. Our primary objective was a streetable tune-up, something that would run all day long on pump gas and that was rich enough to work with the nitrous, but not so fat that it would suffer during everyday riding on the motor.
With the motor buttoned up and the bike strapped down to the dyno, Moon first established an all-motor baseline that produced a stout 186.84 hp and 114.65 ft. lbs. torque-very impressive numbers from just a full exhaust, Power Commander and TRE, or basically $1400 worth of aftermarket goodies that you could bolt on in an afternoon. Once he was happy with the all-motor number, Moon armed the nitrous system and sprayed a pass, resulting in an even more impressive 214.49 hp and 130.64 ft. lbs. torque, an improvement of 27.65 hp and 15.99 ft. lbs. Again, this is an all-day streetable setup, with a mellow map, the #30 nitrous jet and pump gas. With a tank full of race fuel, a bigger nitrous jet and a more aggressive injection map, you could see even more gains. But almost 30 instant, smooth-hitting horsepower from the $500 nitrous system was a perfect result for us.
With a healthy 214 hp on tap, we were almost ready to launch our 200 mph assault at Maxton-just a few more safety considerations to take care of first. The ECTA requires all race bikes to run a steering damper to maintain control on its rough racecourse, and since the ZX14 doesn't come from the factory with a damper, we made another pick from the Muzzys ZX14 catalog and lined up one of their steering damper kits ($689.95) that utilizes a HyperPro RSC variable-speed damping unit. The HyperPro piece offers 22 levels of damping and, unlike other dampers, the damping resistance is based on rate of movement-damping force is lighter at low speeds and higher when the shaft moves at a higher speed that requires more damping force. ECTA rules also require all race bikes be equipped with a tether kill switch. We like the simple functionality of the universal flat-mount kill switch ($58.95) by Vortex, so we further crowded our cockpit with one of those sourced through Orient Express. Finally, because our nitrous bottle was mounted outside of the frame rails, we needed a valve guard. We chose one from Tiger Racing ($59.95), provided by Rob Bush at Fish's Customs.
So equipped, we headed off to Maxton to see what the big, bad Ninja would do. The ZX14, like many sportbikes, has a top-speed governor to stop the bike from accelerating beyond 186 mph. The speedometer controls the governor on the ZX14 (the speedo pickup is on the countershaft), and unfortunately, we weren't able to get a Speedo Healer that would override that governor in time for the event. Instead we upped the countershaft sprocket from a 17t to 18t from Vortex, which effectively slowed the countershaft down and upped the point where the governor kicked in from 186 to 196 mph. We launched the Ninja on the motor-it was hard enough to keep the rear tire from spinning and the front from heading skyward with 186 hp. The air shifter performed flawlessly with instant upshifts to keep the bike accelerating in the peak of the powerband. Wanting to ensure that we didn't run out of nitrous before sixth gear, where we'd need as much horsepower as possible to overcome the high-speed aerodynamic drag, we only sprayed through fourth, fifth and sixth gears. The extra 27 nitrous-fueled hp kicked in smoothly and rocketed the bike all the way up to 196 mph, right against the speed governor, a few hundred yards before the speed trap. This was with 18x41 gearing; we had also packed 40t and 39t rear Vortex sprockets, too. According to more experienced racers, each tooth down in the rear would be worth almost 3 mph on top. So in theory with an 18x39 gearing combo-the tallest combo we thought we could pull to redline in sixth with 214 hp-we could mathematically achieve 202 mph. Unfortunately, this would remain a theoretical speed as we ordered the wrong sprockets, and the ones we had with us wouldn't fit the bolt pattern on the Gale Speed aftermarket wheels mounted to the bike, so 196 mph was as fast as our project ZX14 was going that day.
So close, yet so far away.