In Search of the 11 Second CBX - page 2

The trap speeds suggested that the 1980 CBX as represented by 1471 had dropped more than five horsepower compared to earlier models. All that had been lost, according to the information which Doornbos received from the factory, was five horsepower. Short of putting the bike on the American Honda dyno, Doombos had no way of knowing exactly how much horsepower disappeared from 1979 to 1980. Seat-of-the-pants impressions ("Heck, she's a jet!") can't distinguish a 75-horsepower CBX from an 85horsepower model. Still, Doornbos wondered and we wondered. Time was short. All American Honda could do was fit a new clutch and return the bike to Cycle.

Back 1471 went to the drag strip. Twelve sixteen, 111.11 mph. That was it. Then directly to the Webco dyno. Seventy-one and change, tops. Everything fell neatly into place. One-four-seven-one was a 12-second bike because it didn't have the horsepower to be an 11-second one.

Honda wanted an 11-second CBX, and they didn't have it. After the first quarter-mile try, Doornbos had telexed Japan, alerting the factory engineers to a potential problem. From the beginning, Honda was determined to have a legitimate 11-second CBX. The company could not and would not tolerate anything else. Some 1700 had already been built; many were on the water, destined for American warehouses; Cycle had discovered that the bikes were less than the factory expected; if necessary, the CBXs would be changed. It was a matter of pride, and face.

When CBX 1471 got back to American Honda, it went straightaway on their dyno: 74.47 horsepower. It was a bit more than 1471 made on the Webco pump, and absolutely consistent with past experience. Dynos vary slightly, and the blower- installation at American Honda cooled the CBX a bit better than the Webco setup. When the CBX warmed up (head temperature) from 275 degrees F to 300 degrees F the maximum horsepower fell off to 68.07. The significance of that would become apparent later.

By mid-September Honda had other CBX test units. They went on Honda's dyno: the best one made a little over 78 horsepower; the worst of the lot remained old 1471, with 74-plus. And on the same dyno, Doornbos knew that a 1979 Honda CBX would produce 86 horsepower. So the problem wasn't just 1471; the problem was every 1980 CBX that had been built, everything in the first production batch.

Things began to happen quickly. First, in Japan, factory technicians began to isolate the problem: the mechanical spark timing advancer used in 1980. The 1980 unit (H/C 92011 P/N 30220-469-024) was a single-stage advancer, hereafter referred to as the 469 unit. It had replaced a more complicated dual-stage advancer unit used in 1979, hereafter termed the 422. The factory telexed American Honda: try putting a 422 dual-stage advancer in a 1980 model. That was done in the American Honda dyno room. With the 469, horsepower of one test CBX topped 76; switching to the 422, the peak horsepower soared to almost 86. Terrific! The factory advised American Honda that a new-series dual-stage advance unit (469A) would quickly be available for 1980 CBX Hondas.

For American Honda's Product Evaluation Department, and specifically Doornbos, the quick-fix hadn't come soon enough. First, none of this spark advancer information developed in time to have any bearing on Cycle’s exclusive road test of the 1980 CBX. Second, it wouldn't have made any difference anyway, because there was no such thing as a 469A advancer in the United States until late September. Third, before any ignition change could be made to a 1980 model, the modification had to be cleared with the Environmental Protection Agency; Honda would have to certify that the modification would not carry the 1980 CBX outside the emission limits. Finally, while Honda intended to retro-fit every 1980 CBX with a new ignition unit, no detailed plan and no parts would exist until December 1979.

Happily, no 1980 CBX would be released to dealers until the last week in December 1979; if American Honda wanted to do a warehouse retrofits it could only do so when the parts became available after EPA clearance. So as of late December 1979, every 1980 CBX in the crate had its 469 single-stage advancer; every one had the same specification as the one that had been tested by Cycle.

The EPA was less a problem than one might suspect. Motorcycle manufacturers self-certify their products; that is, they provide documentation to the EPA that their products meet current emission standards. Honda has, for example, emission labs in Gardena, California, and Ann Arbor, Michigan. Honda applied to the EPA for a running change within parameters already established for the 1980 CBX. The CBX had earlier been certified within emission levels and at certain horsepower levels (the two go together). The running modification (substituting the 469A for the 469 unit) was a recovery action-to bring the CBX to the horsepower level previously certified (but not actually reached by the first 1980 CBX engines) and to stay within emission limits. Honda filed the report with the EPA on November 1, 1979, and it was accepted by the EPA on November 6,1979. Only then was it legally possible to change the units.

   

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