The intake trumpets on the...
The intake trumpets on the new '09 ZX-6R feature a unique "sub-throttle port" design that is claimed to provide benefits at both high and midrange rpm power. The lower openings act like a short intake at high rpm by matching the intake resonance at that engine speed, improving flow and overall power.
The intake funnels themselves feature an innovative "sub-throttle port" design intended to improve both midrange and top-end power in a manner similar to variable height intake funnels but without the weight and complexity. Each funnel has a shorter sub-funnel molded into its forward-facing portion; while the taller main portion works with the longer intake resonant pulses at midrange rpm to improve power in that area, at higher rpm the shorter sub funnel helps enhance flow by not only matching the intake resonance better but also provides a straighter path for the incoming airflow from the redesigned ram-air induction system.
That ram-air system has been slightly changed with a shorter but incrementally (2mm wider) larger cross-section that increases overall airbox pressure at speed. The duct itself has been reinforced so that it now fully supports the instrument panel and mirrors, eliminating bracketry and weight.
Down below, an all-new titanium exhaust system replaces the old underseat setup with an underengine unit utilizing the same type of pre-chamber as the ZX-10R's to cut noise and reduce muffler volume. A single catalyzer featuring a higher-flowing 300-cell design keeps unwanted emissions in check.
On the chassis side, the new ZX-6R's twin-spar aluminum frame underwent subtle tweaks to the cast and extruded members (such as a switch from convex to concave cross-section in a similar fashion to the ZX-10R) to tune chassis rigidity for better feedback. In order to reduce the bike's polar moment of inertia (for quicker handling), the engine is actually rotated upward on the countershaft axis 4.6 degrees, moving the front portion up 16mm; the steering head pipe was moved up 10mm to make room. Rake and trail get quickened up as well, moving from 25.1 degrees/110mm to 24.3 degrees/104mm.
The new Showa BPF ("Big Piston...
The new Showa BPF ("Big Piston Fork") features a significantly larger internal damping piston that contains both rebound and compression damping mechanisms, so both adjusters are now located on the fork cap (right) while the spring preload adjuster is now positioned on the bottom where the compression damping adjuster used to be (left).
A new Showa BPF (Big Piston Fork) inverted fork is featured up front. Interestingly, instead of the usual internal damping cartridges that utilize 20-25mm pistons found on conventional inverted forks, the Showa BPF unit basically does away with the internal cartridge and transforms the lower fork tube itself into the "cartridge". This enables the use of a comparatively huge 37mm piston that significantly increases the amount of oil that can flow through the damping orifices, which in turn reduces the possibility of cavitation that can cause irregular damping. The large piston contains both rebound and compression damping mechanisms. The fork spring is still located on the bottom; but, the adjusters for both rebound and compression are now positioned on the fork cap, while the spring preload adjuster is situated on the bottom of the fork leg where the compression damping adjuster used to be. The rear shock remains unchanged, but gains a "pillow ball" upper mount that spreads suspension loads better.
The switch to an underengine exhaust meant the rear sub frame could be made lighter, so the new section is now made from two precision die-cast pieces. A side benefit to the new rear sub frame is a 10mm reduction in seat height. The '09 ZX-6R gains new bodywork styled to strikingly resemble its ZX-10R big brother, as well as a similarly styled instrument panel featuring an analog tachometer with inset LCD panel; special UV-blocking glass is claimed to make the LCD panel easier to read at a glance.
Unfortunately other important info such as weight and list price weren't available at press time. However, Kawasaki reps state that the target weight for the new ZX-6R was the Honda CBR600RR, the current flyweight of the class, and if all the upgrades hit their mark, you can bet the new Kawasaki will shake up the middleweight category. And it's highly unlikely that the MSRP will be set well outside current 600-class norms.
We'll have ridden the new ZX-6R by the time you read this, so expect a full report in an upcoming issue.