The LeoVince Underbody EVO...
The LeoVince Underbody EVO II exhaust is stainless steel with a carbon end cap that’s claimed to dissipate heat better and not affect tire temperature. The exhaust utilizes a larger sub muffler as well, which should quell the exhaust note.
The Ninja's inline-twin engine doesn't exactly match the bike's aggressive outward appearance and is without any race-spec cams, high-compression pistons or head work. The lack of costly internal modifications means power is nearly on par with the last 650 we put on the dyno, although to the project bike's credit, there's a slight increase in power that comes courtesy of a LeoVince Underbody EVO II exhaust ($809). The system is one of two LeoVince options and has more advantages than just increased power, claims the exhaust manufacturer. "We found that the stock exhaust would heat the right side of the tire, but the carbon fiber tip on the [Underbody EVO II] exhaust dissipates heat better and keeps the tire temperature down," says LV's Tim Calhoun. LeoVince also notes that its Underbody exhaust is quieter than most race exhausts thanks in part to a sub muffler, something our paddock friends will likely appreciate during early morning engine warm-up sessions.
Power may not have been the primary concern when it came to the Ninja, but that's not to say we didn't want to show up to the racetrack with a strong performing bike. Point in mind, we turned to Driven Racing and Dynojet, both of whom have an extensive history at the track. From the former we garnered a set of sprockets ($65.97 for the rear, $31.46 for the fronts) and a green chain ($170.22), while from the latter Kawasaki purchased a Power Commander V ($399.95) and a quickshifter ($276.47), two components that would make tuning and riding the Ninja in anger much easier. We also put in a call to Yoyodyne based on a suggestion made by Danne, who claimed that a slipper clutch would pay big dividends in terms of corner-entry stability and lap times. An $850 credit card charge later and we were so equipped.
Danne and Catalyst Reaction's James Morse put the project bike's chassis under the knife-in spite of the fact that Kawasaki had already installed an aftermarket shock and a ZX-10R-culled Öhlins NIX 30mm front fork cartridge kit. "The bike was sitting way too high in the front and really low in the rear, so we really needed to work on the chassis and get the suspension dialed in," says Danne. The changes that ensued include new springs, updated valve stacks that'll ideally provide better damping characteristics through the stroke and a new ride height measurement. Out back, Tige made more drastic changes in the form of an all-new, prototype-style Elka shock that offers more ride height and is equipped with a valve stack that's identical to what he's run on prior Ninja 650 race bikes. Important to mention is that an identical shock to what we've used will be available in the near future; consider us willing guinea pigs.
Our race-prepped Ninja is...
Our race-prepped Ninja is just over four horsepower stronger than the last Ninja 650 we tested thanks in part to the LeoVince exhaust and some fine-tuning on the dyno.
The Cyclemall crew didn't end their efforts there, and willingly dyno-tuned the Ninja in a last-ditch effort to extract as much power as possible. The bike got a general going-through as well, something we recommend for every bike that's headed to the track.
So what's next for our Ninja 650? We're currently registered to race at Chuckwalla Valley Raceway with CVMA, a newly founded Southern California-based race organization that's shown to offer especially great competition in the lightweight twins classes. Check back next month to see how our little Ninja fares.
Bridgestone Battlax Dry Slick Race Tires
Although many race organizations and race classes mandate DOT-approved rubber, CVMA's Formula classes have no such regulations, thus our decision to run Bridgestone's JSB1000 dry slick race tires on our Ninja 650 project bike. The tires are available in multiple sizes and in three compounds, an ultra soft (YDC), soft (YCX) and medium (YCY), each of which we considered using based on Chuckwalla's track surface and expected track temperatures. In the end, we went with a YCX front and YCY rear, a combination that we feel will offer great longevity in addition to sufficient grip. We don't expect our 67-horsepower race bike to have an overwhelming tendency to test grip limits of course, but we're absolutely looking to garner as much traction as possible come race time.
The slick tires should offer multiple advantages when compared to a set of DOT race tires, including a more stable and consistent feel thanks to no treads. We're excited also to see how many tires it takes to get us through three full days at the track; one of the ideas behind small bike racing is that it's easier on your wallet, and if we can make our two sets of tires last for an ample amount of races, we should theoretically be able to keep our expenses within check.
For price and availability regarding Bridgestone's dry slick tires or any of its DOT race tires, be sure to refer to your local race tire distributor.