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Difference between revisions of "2006 Honda CBR1000RR development"
2006 Honda CBR1000RR development (edit)
Revision as of 22:18, 23 November 2010
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* New intake and exhaust porting | * New intake and exhaust porting | ||
* Higher compression ratio | * Higher [[compression ratio]] | ||
* Revised cam timing | * Revised cam timing | ||
* More intake valve lift | * More intake valve lift | ||
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In the ultra-competitive liter-class [[sportbike]] wars there's no time to rest, no free lunch, no easy path to improvement. Which is to say the CBR1000RR's improvement in power output was achieved not with any single change, but rather with a collection of carefully developed modifications that add up to a significant boost in performance. | In the ultra-competitive liter-class [[sportbike]] wars there's no time to rest, no free lunch, no easy path to improvement. Which is to say the CBR1000RR's improvement in power output was achieved not with any single change, but rather with a collection of carefully developed modifications that add up to a significant boost in performance. | ||
To start, the cylinder-head's intake and exhaust ports were refined in shape and size to yield a straighter path for higher flow--and a resulting significant improvement in power feel. The reduced volume in the combustion chamber provides a distinct increase in the compression ratio, from 11.9:1 to 12.2:1, although this alteration was achieved in a slightly unusual fashion. Rather than change only the shape of the combustion chamber proper, Honda's engineers also reshaped the surfaces of the intake valves that face each combustion chamber; shallower dished-out areas essentially add material to the chamber to reduce volume and help raise the compression ratio. To nullify any weight gain to the intake valves, each valve had a corresponding amount of material removed on the opposite side of the valve head, in the area near where the valves rest in their seats. | To start, the cylinder-head's intake and exhaust ports were refined in shape and size to yield a straighter path for higher flow--and a resulting significant improvement in power feel. The reduced volume in the combustion chamber provides a distinct increase in the [[compression ratio]], from 11.9:1 to 12.2:1, although this alteration was achieved in a slightly unusual fashion. Rather than change only the shape of the combustion chamber proper, Honda's engineers also reshaped the surfaces of the intake valves that face each combustion chamber; shallower dished-out areas essentially add material to the chamber to reduce volume and help raise the [[compression ratio]]. To nullify any weight gain to the intake valves, each valve had a corresponding amount of material removed on the opposite side of the valve head, in the area near where the valves rest in their seats. | ||
Other performance-up measures include new valve timing and more lift (from 8.9mm to 9.1mm) on the intake side to help boost power, and a new double-spring design for the intake valves replaces the single-spring setup previously used--all the better for enhanced power output and reliable operation at higher engine speeds. Specifically, torque now peaks at 10,000 rpm, 1500 revs higher than before, and engine redline increases from 11,650 rpm to 12,200 rpm with the 2006 model. In conjunction with a larger rear sprocket (from 41 to 42 teeth) these changes enhance acceleration while top speed can remain unchanged. Usually, gains made in a larger rear sprocket's sharper acceleration must be paid back in reduced top speeds, but this new engine's taller [[redline]] and stronger high-end power output maintain the CBR's high top-speed ceiling for performance. | Other performance-up measures include new valve timing and more lift (from 8.9mm to 9.1mm) on the intake side to help boost power, and a new double-spring design for the intake valves replaces the single-spring setup previously used--all the better for enhanced power output and reliable operation at higher engine speeds. Specifically, torque now peaks at 10,000 rpm, 1500 revs higher than before, and engine redline increases from 11,650 rpm to 12,200 rpm with the 2006 model. In conjunction with a larger rear sprocket (from 41 to 42 teeth) these changes enhance acceleration while top speed can remain unchanged. Usually, gains made in a larger rear sprocket's sharper acceleration must be paid back in reduced top speeds, but this new engine's taller [[redline]] and stronger high-end power output maintain the CBR's high top-speed ceiling for performance. | ||