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Comparison of the Honda CBR 900 RR with the Honda S 2000

Hondadi, Hondada

Sports motorcycle or sports car? Where are the strengths and weaknesses of both concepts? MOTORRAD ran two extreme recipes from the same kitchen.

Turn the ignition key, press the start button, the in-line four-cylinder comes alive with an emphatic hum. First gear, release the clutch, drive off and – enjoying the short shift travel – accelerate comfortably through the gear steps. In the sixth, the speedometer digits form 140, the rev counter oscillates at 5000 rpm. Everything is very unusual. Unusual? Unusual because the background noise of these revs is experienced behind the steering wheel of a car. 5000 / min, in last gear, recommended speed ?? and the tachometer promises 4,000 more revs. Revolutions, everyday for motorcyclists, a new world of experience for the autopilot.
Our sturdy roadster is called the Honda S 2000, is equipped with high-tech up to the ears, has brilliant revving power and a record-breaking liter output ?? at least among the naturally aspirated automobiles. The Honda pushes 240 hp or around 120 hp per liter of displacement. If you let it run free, its pistons, which are attached to forged aluminum connecting rods, oscillate up to 8,700 times per minute, with our test copy – borrowed from Polybauer boss Dieter Weber and slightly refurbished with wheels and aprons – even over 9,000 times.
Quite busy, also in view of the mechanical stress a two-liter four-cylinder is exposed to at such speeds. But it seems stable, because the Honda men confidently grant their barrel organ a three-year or 100,000-kilometer guarantee. The owner of a new CBR 900 RR only gets two, but without any mileage regulation. 120 hp per liter? He can smile about that, even a badly moving model has 145 hp, the little sister CBR 600 F even over 180 per liter. In terms of the individual displacement of a cylinder, the four-cylinder car can certainly compete with a liter twin, such as that of the Ducati 996.
However, roadsters and sport bikes operate differently in order to generate their performance and its course. The car engine is quite long-stroke, reaches correspondingly high piston speeds: 24.4 meters per second on average at maximum speed, only 20.7 for a motorcycle. In addition, the stroke / bore ratio of the S 2000 is only slightly over-square with 0.97, while the Fireblade with 0.73 shows a value that is more tame than motorcycles, but overall more aimed at top performance. As a result, the valve surfaces of the motorcycle engine are relatively larger, and both engines are compressed in a similar way.
It’s very interesting that both power plants use tricks to hide their weaknesses. The two-liter, which is basically trimmed for power in the lower speed range, gains at high speeds through timing and cam lift variation ?? an oil pressure-controlled locking pin in the rocker arm disables two tame cams and one sharp one in operation. The Fireblade, on the other hand, uses a flap in the air filter box to vary the intake volume, depending on the engine speed, and a roller valve between the manifold and header pipes for various exhaust configurations that are optimally suited to the engine speed range in order to add juice in the lower engine speed range.
Why do both concepts of performance approach each other from different angles? The car, which weighs around 1360 kilograms with its driver, has to provide a lot of horses even at low engine speeds in order to move its masses confidently and to act casually at all. When loaded with the same rider, however, the motorcycle only tows 280 kilograms from the start. The performance characteristics can weaken, especially in the lower speed range, because the horses are easily enough for that little bit of mass. If you compare the performance per weight (curves on page 50), the advantages for the Fireblade become obvious.
Consequently, it accelerates impressively, pulls through more brutally, as the measured values ​​show. Of course, the balance sheet for the car could be improved if weight had been saved even more consistently than already. But who spends 65,000 marks to do without electric windows or electric soft top, air conditioning, stereophony, then ABS and airbags? Especially since the Fireblade, with a regulated catalytic converter and high-quality components, is lavishly equipped and could in principle still slim down.
Incidentally, the difference in acceleration becomes smaller and smaller as the speed increases. Reason: the different air resistance of the test persons. The CBR offers the airstream a small frontal area, but has a comparatively poor drag coefficient. In the car, on the other hand, the air only slips past the smooth surfaces, but the frontal area is much larger. Ultimately, the product of the two values, Cw x A, is decisive for the driving resistance. Since the power required to achieve a speed – factored in this way – increases to the third power, the many horsepower of the car constantly bring the mileage closer to the comparatively few of the motorcycle. In the present case, however, the CBR clearly has the top speed nose at 274 to 241 kilometers per hour. More powerful and aerodynamically cheaper cars can also make life difficult for a Fireblade at high speeds.
At high speeds, the chassis of coaches and motorcycles must provide ample reserves. It goes without saying that both concepts oppose the large amount of kinetic energy with stable and powerful braking systems. The S 2000 relies on the torsional stiffness of the self-supporting body (normally problematic in convertibles), using a kind of additional frame in the form of the particularly rigid center tunnel. He also does everything on the chassis side to be up-to-date and to keep pitching or rolling movements as low as possible. In addition, the concept creates both a low center of gravity and an almost optimal weight distribution between the front and rear axles. Measures that pay off, because the tightly damped roadster is up to the limit like the proverbial board, steers in with the agility of a go-kart, which makes it a little more nervous than dad’s station wagon at top speed. Incidentally, a differential lock helps him transfer power to the asphalt. In spite of this or because of this, lease is advised in the border area in order not to lose the toxic Honda. The Fireblade counters with the well-known and much-cited qualities of its chassis, which is certainly one of the best series chassis.
W.o Are there advantages and disadvantages between a Honda two- and four-wheeler? The Blade certainly covers a kilometer on the Autobahn faster than its four-wheeled counterpart, but has to refuel much more frequently. The S 2000 always consumes more, but thanks to the larger tank, the bottom line is that it always makes good meters. Not particularly comfortable for a car, it still pampers its driver with a level of comfort that the leather-clad rider of the CBR can never expect. And this is exactly where the concepts separate. Even a series-produced motorcycle that certainly makes compromises is, in its entirety, much more extreme than a car, however sporty it is. Because even a dynamic convertible like the S 2000 has to meet a broad spectrum of suitability for everyday use. And with that it loses its fascination. And purely dynamic? Does the blade pull in and out of the curve and away? How exactly can be found in the racing kit on page 50.

Racing

At the regulars’ table, the truth of the strongest usually applies, but the stopwatch and light barrier actually decide between victory and defeat. The S 2000 and CBR 900 RR had to prove their speed in two left-hand bends with different radius, measured by the entry time to the top of the bend, the speed there and finally the exit time. In both bends, the entry times of both opponents are close together, with slight advantages for the Fireblade. Relatively clear then is the advantage of the motorcycle when accelerating out, where it makes up a lot of time. The peak speeds show advantages and disadvantages for the S 2000. How come? Turn 1, in which the S 2000 reaches the higher speed, has a slightly larger radius than turn 2, in which the blade drives faster. While the CBR can always use the entire width of the lane, the lane width of the car limits the drivable line radius, which affects the car in tight bends. The larger the turning radius, the greater the cornering speed of the four-wheeler compared to that of the two-wheeler.

Conclusion

Almost classic aesthetics, a touch of a gentleman’s driver ambience, at the same time agile and simply wonderfully unreasonable – no doubt, a crisp, revving and technically clever sports car like the Honda S 2000 is a lot of fun. Judging by other cars, mind you. Because compared to the Fireblade from the same company, an S 2000 cannot avoid delivering a wide range of everyday suitability. In terms of driving dynamics, however, the motorcycle has the edge in almost every situation, distancing itself from the roadster and probably most of the other production cars when braking, in many corners and especially when accelerating. This is how it is with driving a car and motorcycle: the motorcycle is more extreme, offers the unrestrained, wind-ventilated, active and adventurous driving fun that only two-wheelers can convey.

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