1979 Honda CBX Road Test - page 5

When the journalists returned to Los Angeles one of them called racing instructor Keith Code. Code has a rider improvement school based at Willow Springs, and a wealth of experience with big street bikes at that track. How fast, he was asked, could a pure-stock Superbike negotiate Willow? "Anything under 1:50 is awfully good," he said. "A 1:48 would be exceptional, and a 1:45 would be about as quick as any stocker has ever gone."

On Tuesday afternoon, piloted by a rider who would not only have to fall on his sword but do push-ups on it were he to make a mistake, the CBX turned in a 1:43.

We were not alone with the CBX and the Honda engineers and technicians at Willow Springs. The bike had been brought to this howling wilderness for two reasons: for us to test, and for Honda's agency to film. The Six represents many things for Honda: the depth of its engineering and styling talent, its reawakening interest in high performance, its willingness to rush in where angels fear to tread. The bike is in every way a brutish delicacy, and will be greeted with loud hurrahs when the dealers see it for the first time. To that end Honda had organized dealer meetings in Hawaii and in Japan, at which the CBX would make its celestial entrance.

The problem at Willow Springs was this: the dealer meetings were still a month away, and if information or photographs leaked out early Honda's plans to surprise and delight its dealers would be ruined.

Not only that: the CBX found itself in the California desert under circumstances which could only be described as precarious. Motorcycles are developed for Honda Motor Company by Honda Research and Development Company, which was given its freedom from the parent company in 1960 by Mr. Soichiro Honda himself. R&D's corporate independence is buttressed by its fiscal independence; it is funded by a fixed percentage of the parent company's gross turnover. Traditionally, R&D packs up its new models when the designs are complete and the prototypes are running, and embarks upon the Grand Promenade over to Honda Motor Co. to present the new bikes to the parent company executives.

The CBX-Six left Honda R&D, all right. But it was mysteriously intercepted by the highwaymen at American Honda Motor Co. When it should have been making its bows before the smiling Honda directors in Tokyo, it was instead humping around Willow Springs for us and for American Honda's film crew.

This combination of conditions had nerve endings lit up like tiny prairie fires. Security was drawn down tight; either the CBX was being filmed or ridden, or it was shrouded in covers and tarps, a diamond in a gunny sack. There were documents to sign which by their nature discouraged any loose conversation, and guards to keep out the riffraff. On Tuesday, October 25, the riffraff included Gene Hackman and Paul Newman, who had come to Willow for a spin in their race cars only to be deflected at the gate, and Paul Newman's airplane, which tried twice to land on Willow's straight and finally gave up.

Although from one end of the crankshaft to the other the engine's width is not unacceptably beyond the norm for current multis, the CBX's beaminess extends from its crank ends all the way up to the cam cover instead of pinching in at the cylinder base surface. Viewed from the front, KZ engines and GS engines and XS Eleven engines describe the shape of a thickly-drawn inverted T; the CBX engine is a rectangle.

Except for one area: directly below the crank end-covers. Since a six-cylinder engine is so inherently smooth, Irimajiri was able to scrimp on counterweighting. The crank's two end bobweights - to the left of rod # 1 and to the right of rod # 6 - are roughly half the thickness of the other ten, and their outer faces are cut back at the periphery. The space needed for them in the lower case half is thus reduced, making room for bevel-cuts which improve the CBX's banking angle-even though some of the cornering clearance provided by the bevels is stolen by a pair of case bolts on each side.

If in terms of smoothness and power output an in-line six-cylinder engine could be called a mixed blessing, so in terms of cornering clearance could it be called a mixed curse. A six poses many problems; by its nature it also provides many solutions to those problems. The crankshaft layout is an example; the exhaust system is another. While it would seem obvious that a 1000cc Six would need more total muffler volume than a 1000cc Four if the two engines were in comparable states of tune and if both were responsive to the same decibel laws, such is not the case. There are two reasons for this: first, the displacement of each of six cylinders is smaller, making for smaller bangs. Second, a four-cylinder with a two-into-one exhaust arrangement and the standard firing order subjects each muffler to irregular exhaust cycles. The spark plugs fire at 180-degree intervals, then that cylinder pair rests for 540 degrees. But the Six, with three cylinders exhaling into a common muffler, has its exhaust pulses spread more evenly. Therefore a Six with a three-into-one exhaust (or six-into-two, if you prefer) can get by with smaller, lighter mufflers than a comparable Four, and smaller mufflers have less of a chance to drag the ground than larger ones. To make sure that mufflers do not spark against the pavement, the CBX's angle up and in at the rear.

It all works. After two days of hot-lapping around Willow Springs there are no hero-scratches anywhere on the exhaust system, even though the sidestand foot and the curb-feeler nuts at the ends of the footpegs have been frequently scraped.

Honda has always used careful exhaust system design to extract horsepower. But when the young engineers sat down at the banquet that was to be the CBX they reached beyond conventional aspirations of exhaust performance and towards the outer limits of motorcycle fantasy.

The journalists are at dinner with Mr. Irimajiri, Chief Designer Otsuka, American R&D Research Administrator Ken Nakagawa, and Senior Research Engineer (and former racer) Minoru Sato.

"From the beginning," Irimajiri explained, "our Six produced a smooth jetlike exhaust sound. But with an ordinary exhaust arrangement, it wasn't that close to a jet. We thought if we worked on it we could come up with a motorcycle sound like no one has ever heard before.

"So we sent some engineers to the Hyakuri Japanese Air Force base in Chiba prefecture. For ten days they tape-recorded the sound of Phantom jet fighters, and then came back and designed an exhaust system for the CBX that could duplicate that sound. When I heard it for the first time I was amazed; they had captured the Phantom sound perfectly."

"I rode the bike at our Suzuka test circuit," Sato said. "We had the HERT endurance racers out at the same time. It was crazy. The Six, with its Phantom exhaust, made me feel like I was going 200 when I was only going 100. The bike's sound had a feel - a noise quality and texture - completely different from anything I have ever experienced. It sounded better than the HERT bikes."

"After that," Irimajiri went on, "we contacted Mr. Kume. We told him we had something we wanted him to hear. He came, he listened, and he said, 'You've gone too far. The feeling of that noise is just too much. We cannot build motorcycles that sound like jet fighters.' "

So, Irimajiri concluded, they had to scrap the Phantom exhaust and build something more sensible. Now the bike sounds like a Porsche. But somewhere, collecting what passes for dust in the hospital-clean Asaka research facility, in the company of other experimental components which like Hemingway's Old Man went out too far, rests a mystical arrangement of pipes, tubes, baffles and screens which if attached to a certain six-cylinder, 24-valve engine, gives off the transcendental whoop of a deadly weapon of war.

   

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