![]() ![]() The changes to this year’s R6 go much further than the engine room. The MotoGP-inspired snub-nosed exhaust retains its titanium construction and powerband-enhancing EXUP valve. Meanwhile, several tweaks to reduce internal friction free up more ponies in the upper range, and wider connecting-rod bearing increase durability. Cam timing was subtly altered to augment the new engine tuning. A bump in compression from 12.8:1 to 13.1:1 aids torque production, as do 83% larger crossover pipes in the exhaust headers. To achieve this augmented powerband, Yamaha engineers made several other modifications to the 599cc powerplant in addition to the YCC-I. As long as you use the excellent gearbox to keep the engine in this bountiful range, the R6 will be hard to catch by any other middleweight. From that point, there’s a 6000-rpm strata of ripping high-end power that is a joy to crank up around a racetrack. As before, strong power arrives only once past 10,000 rpm, but now the hit is superior in its quality and quantity. Rocketing out of Laguna’s Turn 11 and onto the front straight reveals seat-of-the-pants impressions that back up the dyno chart, although the R6 still can’t be described as torquey. And at the upper end, a Yamaha rep revealed to that horsepower at the rear wheel handily exceeds 110. Peak torque now arrives 1000 revs sooner at 10,500 rpm. Although the chart didn’t have numbers on it that show exactly the parameters of the power comparison, the curve of the new bike was clearly stouter in the upper midrange. Yamaha showed us a dyno-chart comparison of this new model against last year’s that demonstrate a stronger midrange plus even more power up top. But the system electronically converts to a short intake tract at 13,700 rpm for optimum performance at the top-end. At lower revs, the intake air is fed with the fuel-injection’s velocity stacks in their long configuration for enhanced torque output. Working in conjunction with the bike’s existing YCC-T ride-by-wire throttle is another techie acronym we first saw in last year’s R1: YCC-I, which is a variable-length intake trumpet stack called Yamaha Chip Controlled Intake. The key change to this new R6 is an engine that is architecturally the same but has received some 50 refinements to improve how it delivers its power. The 600cc segment makes up 51% of what Yamaha calls the Supersport market, a segment that is up in sales a huge 52% since 2001. This is a critical class for all manufacturers of sportbikes. ![]() Yamaha invited to the hills and twists of Laguna Seca near Monterey, California, so we could gleefully sample the latest iteration of this sportbike sales success: R6 sales are up 44% since 2001. So in this mid-cycle revision for ’08, the tweaked R6 has a bolstered midrange punch and even better handling dynamics in the face of new-for-2007 challengers from Honda and Kawasaki, plus a revised GSX-R600 from Suzuki for ’08.
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