Kawasaki Ninja ZX Motorcycles - ZX2

There's no doubt motorcycling can be rough on romantic relationships. Getting involved with custom sportbikes can become an all-consuming adventure, sucking up vast amounts of time (not to mention money) that in a more sane relationship might be better spent with your significant other. And considering the universally horrendous passenger accommodations on most sportbikes, you are left with just two choices: start sleeping with your motorcycle or set your partner up with a trick sportbike of his or her own.

For cycle-crazy couple Steve and Shannon Patterson of Louisville, Kentucky, the latter route made the most sense--resulting in the pair of brilliant blue his-and-hers Kawasaki ZXs pictured here. And we're not talking any ordinary Ninjas in the Patterson garage--Shannon's wild ZX-6R features a home-brewed turbo system fabbed up by husband Steve, just the ticket to keep up with Steve's blinged-out, larger-displacement ZX-10R. We're talking some seriously fast fraternal twins.

This ZX-squared madness began when Steve, a full-time firefighter with the Louisville Fire Department, was looking for a new bike to replace his Kawasaki Ninja ZX-12R. Steve loved the alpha Ninja's power but was intrigued by the concept of a lighter-weight, better-handling but still lightning-fast machine--leading him to the idea of a turbocharged 600cc sportbike. Deciding to go ahead with his plan, he selected a 2003 Kawasaki Ninja ZX-6R because its factory fuel injection would simplify the task of fueling the turbo, not to mention the added bump provided by the 6R's comparatively larger 636cc engine. He originally intended to start with a wrecked ZX-6R, but instead began with a factory-fresh new bike purchased from S&S Kawasaki in Clarksville, Indiana.

Since there are no off-the-shelf turbo kits presently available for the middleweight Ninja, Steve's next step was to hit the internet and start collecting parts so he could roll his own. The first piece of this puzzle was the turbo unit itself, an A/R Airesearch piece he scored for a song off of eBay. This was followed with a Tial 35mm wastegate (also e-sourced) and a BEGI rising-rate fuel pressure regulator, which, along with a Bosch 125-psi fuel pump salvaged from another turbo motorcycle, cost Steve a total of just $700 and gave him everything he needed to start setting the bike up.

Steve is nothing if not resourceful, and taking care of much of the handiwork himself allowed him to keep the remaining costs of this turbo build remarkably low. Rather than spending a lot of money on custom pipe bending and an expensive, purpose-built exhaust system, Steve simply removed the stock exhaust and, supplementing it with a generic two-inch exhaust pipe from the local Auto Zone, modified it to work with the turbo. First he cut the exhaust port flanges off the stock header and welded these to short lengths of two-inch tubing flattened into an oval shape. Then Steve fabricated the turbo collector and tack-welded it together, routing the 10-inch exhaust dump out of the bike's left side (unlike most aftermarket turbo systems that exit to the right) in order to better clear the ZX-6R's oil filter.

The next step was locating the turbo, taking care to keep the turbocharger's centerline above the oil pan to ensure proper drainage. After the turbo and collector mount locations were finalized, the wastegate was moved down in front of the oil pan and the exhaust system was finally welded together. The next major challenge was routing the boost tube to the intake side of the engine, passing over the top of the engine and connecting to the homebuilt plenum that replaces the stock airbox entirely.

Aside from the home-brewed turbo kit and custom 0.0050-inch base gasket from Cometic to lower compression to 10.0:1, the rest of the 636cc engine remained stock. After the fabrication was complete, Steve trucked his handiwork to WFO Motorsports in New Albany, Indiana, for some dyno time. Following a few hours of EFI tweaking by WFO owner Shawn Griffin, the boost regulator was set at 8 psi and the force-fed Ninja was strapped to the drum, where it promptly put down 139 hp--a very respectable 30 percent increase over the ZX-6R's stock power output. Not bad, especially considering Steve estimates his total investment in the turbo motor cost $1600 (not counting fabrication time). Who says you gotta go broke for boost?

One thing that didn't come cheap, though, was all that blingin' chrome! While Steve turned his considerable engineering talents to the turbo system, nearly every single remaining component was shipped off to John Reid at Stanton, California's Sport Chrome for a heavy dip. Frame, swingarm, forks, wheels, brakes and dozens of incidental bits were slathered in shine to the tune of $5500 bones. The effect of all this shiny stuff against the factory blue metallic paint is nothing short of arresting.

The turbo 6R turned out so well, in fact, Steve's wife, Shannon, claimed the bike for herself--leaving Steve SOL and in search of a new project bike. Fortunately, he didn't have to go far, just back to S&S Kawasaki, where another blue beauty, this one a '04 Kawasaki Ninja ZX-10R, caught his eye. While it's nowhere near as wild as his wife's ride, Steve's 10R has been tweaked a bit in both the show and go departments. The big Ninja produced a solid 147 hp in stock trim, but before there were even 500 miles racked up on the odometer Steve had the bike stripped down and ready for some aftermarket attention. First the motor was pulled out so the frame (and practically everything else attached to it) could be shipped to Sport Chrome for plating. The bill was only $4300 this go-round, mostly because Steve passed on plating the engine covers. While the engine was out of the bike, Steve yanked the head and installed a factory Kawasaki high-compression head gasket as well as a Micron Serpent full exhaust and a Power Commander PCIII USB--all sourced online from Hardracing.com in Mooresville, North Carolina.

After bolting everything together, it was back to the dyno, where Steve was rewarded with a healthy 159.7 hp--a 12.7-pony increase over stock. The 10R looks as good as it cooks, as you can see from the photos here, and it's stares aplenty when Steve and Shannon hit the Louisville streets together--especially when folks peep the "His ZX" and "Her ZX" license plates. And even though Steve's normally aspirated 10R already has a horsepower nudge over his wife's turbo bike, would you believe he's at work now building a twin-turbo (!) setup for his Ninja, which he expects to complete by next spring?

We just wonder what's going to happen after Shannon lays claim to that bike, too!