The Electronic Era
The Electronic Era
RASE WATCH
When discussing electronics as applied to motorcycles, some people speak as though this were a moral choice. It's not. Electronics have become an integral part of the motorcycle. Here's why.
KEVIN CAMERON
LET'S BEGIN WITH BREAKING PERFORMANCE compromises. Magnetos sparked at one fixed timing (with possibly a simple starting retard), which gave away power because no engine's ignition timing needs are constant as rpm and throttle angle vary in use. Electronics made it possible to match timing exactly to engine needs at all times, eliminating this power loss.
Carburetor fuel systems had to be set too rich for warm-weather operation to prevent potential ly damaging leanness in colder weather. A carbu retor setting that was close to correct at sea level was blubberingly rich at high-country altitudes. All of these compromises had definite costs in power and fuel wastage. Electronic fuel injection has ended these compromises.
An exhaust pipe, intake-length choice or a resonant airbox can be made to give a useful torque boost of about 10 percent in a given rpm range. But at other rpm, there is either no effect or a 10 percent negative effect; torque “flat spots” are created that interfere with acceleration. With computer control, an EXUP-style exhaust valve and variable-length intakes or airbox valves may be used to broaden the range of the boost provided by those devices, or to cancel the flat spots they would otherwise produce. The result is more and smoother power.
What about improving controllability? We humans are good at linear control, in which our movement produces a directly proportional response. We are not so good at strongly non-linear control, in which the response may be out of proportion to the input. This first became a problem in high-performance military aircraft, which can have highly nonlinear aerodynamics, sudden stall departure and the like. In such circumstances, no human’s response loop is fast enough to control them. One of the first tasks of flight-control-system design was to maintain reliable pilot control through such regimes.
Here on Earth, we face our own “nonlinearities.” During maximum braking or on slippery or unpredictable surfaces (gravel or ice, for example), the braked wheels may lose grip and abruptly decelerate and lock, destroying directional control with little or no warning. Electronically controlled ABS has been developed to extend operator control in these situations.
When engines are tuned to low or moderate levels of power, their response to throttle is approximately linear and easily controlled by a human operator. Because two-stroke racing engines of the 1970s depended upon strongly rpmsensitive wave effects, their powerbands displayed sharp non-linearities, which made control difficult. Suzuki’s threecylinder TR750 engine’s torque jumped 100 percent between 6500 rpm and its power peak at 7500, causing rider Gary Nixon to say in 1974, “That’d be a pretty good little engine if it weren’t so damn hard to ride.”
Two-stroke Grand Prix engines received three-dimensionally mapped electronic spark timing in 1987, and electronic torque-limiting and anti-spin in 1990. Four-strokes, which are closer
to being simple air pumps, remained manageably linear in their response until the coming of MotoGP in 2002. Intense competition soon produced engines with strongly non-linear response, the result of having to build higher power by calling upon longer cam timings and intakeand exhaust-wave action.
Existing electronic systems were quickly elaborated to deal with those new conditions. Anti-spin systems came first, followed by “virtual powerbands”—the smoothing of torque curves with ride-by-wire systems that could open the throttle a bit to fill in a flat spot, and the next instant, close it a bit to prevent a torque spike from spinning the tire. This gave riders the confidenceinspiring feel of linear response, just as 40 years ago, early flight-control systems gave hard-pressed combat pilots the feeling that “hot” fighter aircraft were just as smoothly controllable as a primary trainer.
In the early days of MotoGP electronics, there were mistakes, and riders were spooked by things such as midcorner uncommanded full throttles, just as must surely have happened during flight-control system development.
Early motorcycle systems, being prototypes that were evolving day-by-day in the care of highly paid specialists, were extremely expensive. As time passed and important areas were brought under predictable control, dedicated chips were produced and costs came down. In a similar way, fuel injection was once considered costly and exotic, while at present its use has become nearly universal.
Japanese motorcycle manufacturers at first shied away from offering production traction-control and/or ride-by-wire systems. The prospect of product-liability lawsuits is daunting, but European manufacturers had before them the example of ABS—a European development. Not long after its introduction, ABS was considered valuable safety equipment, and insurers offered premium reductions for its use. Traction control is just the inverse of ABS, so Ducati, BMW and Aprilia lost no time in making such systems
selling points for their products. The Japanese are only now belatedly trying to make up lost ground with production systems of their own. Meanwhile, ABS, traction control and even yaw control have been routine options on production automobiles for years.
It had long been a point of honor for motorcycle magazine test riders to outdo any new motorcycle ABS. This presumably showed that such systems were only for newbies who couldn’t do up their own diaper pins. Then, two years ago, Honda’s new Combined ABS became so good that Cycle World's veteran Road Test Editor, Don Canet, revealed it had taken him five tries to “beat it.” And he commented that in an emergency, you get only one try. This was inevitable because electronics operate at essentially the speed of light, while
human axonal conduction runs at a few feet per second. ABS has been improving steadily for years, but human capabilities remain what they are.
Some people feel that manual controls are “pure” in some way, but Formula One now uses exclusively drive-bywire and automated shifting with up/ down paddles on the steering wheel. Dual-clutch transmissions have made considerable headway in high-end cars because they achieve zero shift delay.
All of these things are coming to motorcycling because they offer improved function. Old-timers may resist this for a time, but the change is coming because it works.
What about the comments made by famous racers, such as Valentino Rossi’s expressed wish that all electronics be removed from MotoGP? Others have complained that electronics allow lesser riders to compete with their “betters.”
History can give us perspective here.
In 1901, Christian Lautenschlager’s Mercedes was given a foot-operated throttle. Before that, drivers controlled engine power with only an ignition cut-out—on or off. The foot throttle made it possible to take comers in smooth slides rather than as a series of sudden jerks. Was the foot throttle wrong because it made it easier for more drivers to go fast?
In 1980, some riders looked down on Wes Cooley Jr. because he was fast and smooth on a four-stroke Yoshimura Suzuki GS 1000 Superbike but not firstrank on a two-stroke Yamaha TZ750. Should riders lose “style points” for riding a more controllable (Le. better) bike? Was Cooley’s four-stroke “wrong” because its smoother power made it easier for him to go fast? If electronics smooth the power of a MotoGP bike, is that “wrong?”
People say electronics make MotoGP boring. They want to “bring back the excitement” of two-stroke 500s. I ask, “Do you mean bring back highside crashes and rider injuries?”
“Well, no, but, you know, those bikes were really exciting to watch.”
I ask, “Must we come up with a technology that makes it look like the rider’s going to highside, but then somehow prevents an actual crash and injury? Would that do it for you?”
During the 500cc era, Mick Doohan won five consecutive world championships. Today, with “electronic bikes,” at least five MotoGP riders— Rossi, Casey Stoner, Dani Pedrosa, Ben Spies and Jorge Lorenzo—are potential winners.
In 2010, Cycle World organized an AMA Pro Road Race team that competed in four American SuperBike nationals with rider Eric Bostrom and crew chief Richard Stanboli. In the course of that season, I got to see some of the possibilities for learning and analysis that now exist within the MoTeC electronic system on the Team Cycle World Attack Performance Yoshimura Suzuki. Engine midrange torque often suffers from slow combustion, the result of reduced intake velocity. Stanboli knew that the GSX-R1000 has computer-controlled secondary throttles. He decided to see if they could be programmed to increase part-throttle intake velocity. Upon applying the control software he wrote for the purpose, he found 3-4 extra midrange horsepower.
When Bostrom was losing time trying to match engine and gearbox speeds during corner entry, Stanboli thought of the Suzuki’s throttle positioner. Its purpose in the stock motorcycle is to maintain idle speed during warm-up. Could that positioner also function as a throttle blipper? Again, he wrote some software and was rewarded with faster laps.
The half-truth is that slipper clutches make corner entry easier by preventing engine braking from dragging or hopping the back wheel. The rest of the truth is that a slipper can only be optimal for one gear—but the transmission has six! Stanboli was able to use his MoTeC system to command the throttle positioner to raise the idle during deceleration (possibly by different amounts in each of the first three gears), thereby canceling any desired part of the remaining engine braking.
By looking at data acquisition from practice and making such experiments, an interested person can “take apart” the elements that make up comer entry or comer-exit acceleration or any other situation, then understand them better and finally devise ways to help the rider make the best use of personal taskmanagement ability. Despite the NHRA’s well-known ban on control electronics, drag racers have for years used data systems with great sophistication as a means of optimizing clutch setup, traction and shift points. The computer traces display the whole run graphically against distance traveled, making it easy to compare this run with previous best mns as a means of moving toward an optimum.
Roadracing today seeks to de-emphasize the role of technology with the stated goals of making competition closer and cheaper. This can become quite complex as in, “You may use these washers in your fork but not those, which come from a damper set that is not homologated for your class.” Electronics are not a part of the new Moto2 class. By effectively “freezing” technology at an arbitrary level and with a particular hardware menu, racing series disconnect their vehicles from the mainstream, which continues to advance as previously described.
One effect is to reduce manufacturer interest, since a major goal of racing throughout the past 100 years has been technology development. Another effect is that news of racing could cease to include news about motorcycles, as promotional emphasis shifts to traditional athletic trivia. (What’s your favorite burger joint or your girlfriend’s pet name?) This magazine is about motorcycles, so it may be that racing will at some point no longer interest our readers. □
