When the EPA enforced even tighter tier two emission regulations in 2009, Yamaha was caught with its pants down as a new EPA/DOT test was also introduced that measured the emissions a motorcycle puts out at full throttle. Unfortunately, the company apparently wasn't expecting these stricter tests and the YZF-R6 appears to have fallen victim to this test in '09. You may remember one of the features of the '08 R6 that we particularly liked was its performance past 10,000 rpm, where the engine seemingly comes alive. At the same time, the YCC-I variable length intakes emit this ferocious intake growl as it sucks in as much air as it possibly can to deliver this performance. For '09, Yamaha hastily met these new requirements via ECU tweaks that effectively leaned out the fuel mixture at the top of the powerband, between 10,000 and 12,000. This allowed the bike to pass the government checks, but killed all of the thrust that our testers raved about the year prior. In fact, this became a chief complaint during our '09 600cc shootout.
We weren't the only ones to complain; you the consumer made your voices heard as well. Well dear reader, don't think the manufacturers weren't listening. Yamaha, wanting to appease its current (and future) customers and bring the R6's performance back to its former glory, again went back to the drawing board for improvements. Consider the latest YZF-R6 you see here more an evolution of an essentially four-year-old design (further proof that the current state of affairs in the economy has put an end to the Big Four's fever-pitched two-year development cycles).
2010 sees a 100mm longer exhaust...
2010 sees a 100mm longer exhaust to please the sound police and to supposedly allow the ECU changes to unleash the power lost the year before. Unfortunately the dyno shows otherwise.
Not that the R6 needs any introduction, especially since its basic architecture has remained virtually the same the past four years, but its 599cc inline four-cylinder engine was the first in its class to receive the Yamaha Chip Controlled Throttle and then the Yamaha Chip Controlled Intake stacks in '08. During our 600 shootout of '07, the R6 was the horsepower king of its class, with 105.6 ponies-equaling that of the Triumph Daytona 675 and its larger displacement engine. The following year, Yamaha engineers were able to squeeze even more performance, to the tune of 108.3 horsepower. During our track testing, all testers raved about the Yamaha's power high in the powerband, though we all agreed the bike was a pain on the street. Its paltry torque output (hovering in the lower 40 ft-lb range) and sticky clutch made launches off the line quite difficult.
Come 2009 and the new Tier Two EPA regulations, and the R6 quickly lost its former glory. As we mentioned earlier, in order to meet these tighter emission tests and the EPA's sound regulations, Yamaha essentially detuned the bike via ECU changes. This is evident when looking at the dyno chart; the '08 machine shows steady progress along the rpm range, while the '09 shows heavy dips and inconsistent fueling starting at 11,000 rpm. On the bright side, Yamaha did make up a little in the torque department, but not enough to offset the drop in top end steam. Again, this is something our testers noticed during our '09 600 shootout, as everyone agreed the R6 was lacking compared to its former self.