|GS1100 vs CBX - page 2|
While the two bikes cooled off, we looked at the time sheets, checked clutches and planned strategies. "Both are being slowed down a little by this headwind," Jeff figured. "That run on the Suzuki was about perfect, but I might be able to shave a tenth, maybe even two, off the Honda's time. There's no way it will go as quickly as the Suzuki though." But by the time the bikes had cooled off and Jeff was ready to go again, that headwind was increasing in force and neither bike could run a better time, although all of each bike , s set of four or five runs was under 12 seconds. It didn't matter though, the point was made: There's a new King of Quick stalking the streets of America and it wears the name Suzuki.
The next dragstrip test was the High-Speed Passing Test. Each bike rolls down the strip at precisely 50 mph in fifth gear. Exactly 200 yards from the speed trap, the rider turns the throttle on all the way and accelerates without shifting. This is about the equivalent to the distance traveled when you pass a car in top gear. The speed traps give the bike's final speed at the end of the run. The GS1100's average for three runs was 80.2 mph. The CBX was exactly one mph slower. This makes both of them pretty comparable to the 1980 Yamaha XS1100 which although slightly faster at 81.1 mph, wasn't confronted with the stiff headwind that slowed these two.
|Suzuki's version of the four-valve head (right) has steeper valves and shallow combustion chambers. Valves are easier to adjust but they will probably need more frequent adjustment then the Honda's direct-actuation shim arrangement.|
The third test for the day was supposed to be braking. However, those eight stops from 120 mph at the end of the quarter-mile runs glazed the Suzuki's front brake pads, turning the GS1100's front brake from a powerful but fairly predictable stopper into a hard-to-control grabber that could be locked with moderate pressure from just one finger at 10 mph. Nobody wanted to deal with a brake that uncontrollable in panic stops, so the braking test was scrubbed. As we put about 1000 miles on the Suzuki in the next couple of weeks, the brake became more predictable and less abrupt, but it never regained its original feel. The CBX's were strong and controllable.
To unlock some of the performance mysteries of these two muscle machines, we took the bikes to Webco's dynamometer. Dyno testing is interesting the first time you do it, but it loses its appeal after that. To install a bike on the dyno, you must remove the rear wheel and bolt the bike down at the rear axle. Then using remote controls, the bike is run with the throttle wide open and a measured load is applied. How much load it can handle at a given rpm determines its power output, measured in foot-pounds of torque and brake horsepower.
|Dual Hy-vo cam chains reduce cam chain whip in the CBX. Although it has eight more valves than the GS, the CBX has less moving parts per cylinder than the Suzuki, which has the extra weight and complication of rocker arms and shafts.|
The dragstrip had already told us that the Suzuki was more powerful than the Honda. The dyno spelled it out more exactly. At 86.67 horsepower and 59.73 foot-pounds of torque, the Suzuki makes over three horsepower and eight foot-pounds of torque more than the Honda. It also peaks at a lower rpm. The Four's horsepower peak is at 8000 rpm, compared to the Six's 9000 rpm. The 1100's maximum torque shows up at 6500 rpm, the Honda's arrives 1500 rpm later. Obviously the Honda is peakier, which isn't surprising. Honda almost always relies on revs to make horsepower.
The Suzuki makes more horsepower throughout the rev range. It has a three horsepower advantage when both bikes are spinning at 3000 rpm. Between 3500 and 8500 rpm, the Suzuki makes between five and 11 horsepower more than the CBX at the same rpm. It also makes between five and 10 foot-pounds of torque more than the Honda at any given rpm in the same range. It's safe to say that the Suzuki is a significantly stronger engine.
However, the Honda makes up for some of its power disadvantage with gearing. Its overall gearing is lower and at any given road speed in fifth gear, it is running at least 500 rpm faster than the GS. As a result, it is usually only two or three horsepower short of what the GS is making at any given road speed, although the Suzuki's advantage jumps to about eight horsepower at about 110 mph.
Incidentally, this 1980 CBX makes about five horsepower less than the 1978 version. This was done to drop the Six's horsepower (at the crankshaft) from 103 to 98, just under the 100 bhp maximum allowed in West Germany. Honda claims that midrange was also boosted by this move, although it didn't show up during dyno testing.