When we last left noted tuner Kaz Yoshima ("Training Wheels", October '06), he had been subtly tweaking an '05 Kawasaki ZX-6RR for more speed while learning his way around the intricacies of the latest data acquisition systems and how they could help unravel the mysteries behind motorcycle handling performance. The brilliant (and still somewhat eccentric) Yoshima is one of those restless engineering minds who constantly needs a challenge, some insurmountable problem to solve. And the incredibly massive and complex amount of data that can be sourced with today's increasingly powerful data acquisition systems was an intellectual treat that was too good to pass up.
Yoshima uses the Racepak G2X...
Yoshima uses the Racepak G2X base dashboard, with an LED digital display (instead of the more common LCD display on other systems that are more difficult to read in daylight). Like most digital dashboards, there are a multitude of data groups it can display.
Although you see most rear...
Although you see most rear suspension datalogging sensors closer to the rear shock to avoid crash damage, Yoshima feels that having the sensor closer to actual wheel travel enables better overall rear suspension data and avoids recalibration whenever the shock linkage or spring is changed.
For his '08 version of the...
For his '08 version of the ZX-6R, Yoshima went with this KR Tuned system to handle exhaust gases. Bridgestone BT-003 DOT racing tires provided excellent grip and consistency for Yoshima's datalogging efforts.
Note that although Yoshima...
Note that although Yoshima has a sensor to measure front suspension movement, he still can't help using the old-school method of a tie strap on the fork tube. Note the tire temperature sensor embedded in the front fender.
Yoshima's attention turned to interpreting the numerous graphs and numbers that can appear like so much gibberish to the average person. In working with some of the top riders in Willow Springs' competitive club racing scene, Yoshima found that obtaining feedback from them that would allow him to help get the bike's suspension dialed in was often a hit-or-miss situation; many of the young hotshoes knew what they wanted the bike to do, but weren't able to adequately describe what it was doing. By using data acquisition, Yoshima could discern what the riders were trying to describe without having to guess.
The initial problem with datalogging was similar to what he was encountering with his riders-without enough information, he was forced to make too many guesses. Fortunately, datalogging systems had already progressed leaps and bounds due to their increasing application in auto racing, so Yoshima looked at the various systems available before settling on the Racepak G2X
unit, a robust GPS-based datalogging system that allows excellent expandability—the same datalogging unit used by SR. Of course, while we're barely scratching the surface of the G2X's capabilities because of time constraints, Yoshima has long since dived in headfirst exploiting every possible avenue of the sensors and software.
With the telescoping sensor...
With the telescoping sensor mounted to the steering damper, Yoshima is able to accurately measure steering movement (if you look at any MotoGP or WSBK racebike, you'll see the same setup). The little L-shaped wire protruding from the right side of the windscreen is a pitot tube to measure wind speed; this allows Yoshima to measure how much of a headwind or tailwind is present at a particular instant.
Yoshima found that because...
Yoshima found that because a motorcycle leans from one side to the other very quickly, it would often lose enough satellite reception lock to result in location data that was too inaccurate for his needs. To counter this issue, he designed and fabricated this tiny gyro-stabilized table for his GPS antenna to keep it as level as possible.
Holy rat's nest, Batman! The...
Holy rat's nest, Batman! The amount of data sources that are logged into Yoshima's modified Racepak data acquisition system are evident with the mass of wiring surrounding the ram-air intake. Because Yoshima is constantly experimenting and tweaking, a much cleaner CAN bus line setup wasn't possible.
Some of his more esoteric pursuits with data acquisition included shock internal pressures and wind speed. Yoshima had discovered that internal pressure variations inside a shock at high speed were too great, and had designed his own proprietary modification to resolve the problem (after measuring them with datalogging sensors) when Öhlins came out with the TTX series of shocks that operate somewhat on the same priniciple (the twin tube design allows oil to flow in only one direction through damping shims, reducing pressure and allowing more consistent damping). He also installed a pitot tube (the same design used on aircraft) to measure wind speed to determine how much of a head- or tailwind is present at any given time.
A sort of resource guide/helpdesk...
A sort of resource guide/helpdesk to all things data acquisition, Kaz Yoshima's website www.docmc.net will offer users access to his vast experience and knowledge with datalogging systems. Yoshima will offer help with datalogging questions, how to properly interpret the often confusing graphs and numbers presented by datalogging, software and hardware questions, etc. Yoshima will even be offering real time advice via Skype.
After two years of working diligently on deciphering data in a way that allows him to diagnose various handling ills (he has even figured out a way to measure tire deflection during cornering and bumps), Yoshima feels that more riders should make use of data acquisition as a tool toward better performance, both from the machine and the rider. And with data acquisition system components becoming more affordable (and even standard, as with the Ducati 1098R's Ducati Data Analysis), the opportunity to use this tool is more accessible than ever before. To this end, Yoshima is in the process of creating a resource/advice/direct communication website to help those in need of assistance decoding the mysteries of data acquisition graphs and figures, and/or motorcycle handling ills. With the growing popularity of internet direct audio/video software such as Skype, Yoshima hopes to soon be able to show customers in real time his interpretation of the data graphs. The site—
www.docmc.net —should be up and running at least in primary form by the time you read this.