[sportrider - features] - Kawasaki ZX-6R Racebike Build | Crunch Time

[Ninjette Newsbot]

As a motorcycle journalist I’ve accepted the fact that I’ll always be in a fight versus deadlines, however that realization didn’t make my time aboard SR ’s ZX-6R project bike any less stressful. When we left off with that bike (“Seeing Green,” December ’13), CycleMall Motorsports was putting the finishing touches on it and scheduling potential test days. Three separate events popped up and seemed workable; the problem was that the first trackday was run only four weeks before the AMA Pro Racing round in late September, meaning the ZX-6R’s development would need to be wrapped up in less than a month’s time. It also meant that I’d spend just four days on the bike before showing up at Mazda Raceway Laguna Seca, whereas the rest of the field would’ve had all year to acquaint themselves with their ride. Talk about crunch time…

My first chance to throw a leg over the ZX-6R came during a Fastrack Riders trackday at Auto Club Speedway, and if it weren’t for me bouncing between the Kawi and another magazinerelated testbike, I’d probably have been a bit nervous. I haven’t ridden any racebike other than Sport Rider ’s 2012 Ninja 650 project bike and maligned Harley-Davidson XR1200X in around five years. I ride a lot, yes, but in this case I had 120 hp to manage, higher expectations, and a laundry list of setups that needed to be gone through if we had any hope of being competitive later that month. You have to ride a racebike with a slightly different mind-set, too. So where I can ride a testbike with some performance in reserve and not do anything stupid, I’d have to ride the ZX-6R as close to its potential as possible so that we could push the limits of its development process. This requires a bit more focus and dedication as a rider, and I’d have to remind myself of this as we went about testing the bike.




Our primary objective on test day one was to get me comfortable with the bike (set the levers, clip-on span, etc.) and to start deciphering the differences between the 2012 and 2013 ZX-6R rear shock link. The structural difference between these two links is minimal; the 2012 link is more progressive than the relatively flat 2013 link and keeps the back of the bike propped up under load, which correlates to more weight over the front of the bike. To confirm the effects, we mounted a 2012 link to SR ’s bike and a 2013 link to our impromptu teammate, Chad Lewin’s, bike for a back-to-back comparison test. The differences were just marginal, with the biggest disparity being that the flat link made the front end feel a bit numb at the entrance of a corner. I noted also that the 2012 link had just a bit less bump absorption, and we’d continue to bounce between these links in an attempt to find some type of advantage—no matter how big or small. At the end of the day both of them had pluses and minuses, and I felt like we could build a setup around either of them, so instead of wasting precious time we decided to pick one—the ’13 link in this case—and run with it.

A week later the CycleMall team and I were at Spring Mountain Motorsports Ranch for a twoday TrackXperience trackday that I’d only get to attend half of as I was flying out of town on that Sunday. It was unfortunate that yet another day had been cut from our already-limited testing schedule, but we made the most out of the weekend by putting my dad, Curtis—a longtime racer and test rider—on the bike the second day. The move was hugely beneficial for me because I left the track Saturday night a bit worried by the development process, but knowing that work would be getting done while I was gone eased the nerves. Moreover, conventional wisdom told us we’d want to keep the bike stiff and up on its nose, but I had a lot of problems getting the bike into and through the middle of faster corners (which Laguna Seca is littered with, unfortunately) and Tige Daane of CycleMall was certain that the bike would work better if we lowered the back, so we still had a lot to figure out.

Tige Daane and the entire CycleMall crew have been pivotal in the development of the Kawasaki ZX-6R project bike, helping not only with bike setup but with a game plan for every weekend we spend with the bike.





We had the opportunity to play with our reflashed ZX-6R ECU during the TrackXperience event, but that too was looking like it’d take more time to develop than originally expected. And in no way was I jealous of Chris Gardell of Flash-Tune Inc., the man tasked with decoding Team Green’s ECU and writing an entire new program for the ride modes, traction control, and engine braking systems. After every session I’d make notes on the progression, and then he’d plug right back into the computer and fine-tune the code.

There were hiccups in the evolution. For instance, at one point I could only switch the riding mode by cycling the ignition on and off—in the pits, of course. In other sessions I could only adjust the traction control while off the throttle, meaning I had to reach for the KTR C switch while on the front brake and decelerating into a corner. Gardell found a solution for each of these problems, though at this point we still had a lot to figure out in regards to intervention and on/off throttle transitions, which needed to offer a balance between smoothness and a quick response.

Chris Gardell was tasked with reflashing the Kawasaki’s ECU and spent most of his time plugged into the computer, writing code. He essentially started from zero and now has a system that allows the rider to adjust the riding mode and traction control system on the fly. Engine braking and the on/off throttle transition have also been updated.





Another aspect that Gardell and Daane paid attention to was engine braking, the majority of which was controlled by manually adjusting the start angle of the primary butterflies, then by managing airflow via the electronically controlled secondary butterflies. Daane says, “There’s too much engine braking, and if we can get the bike to roll through the entrance of the corner better, it’ll help settle the front a bit,” but notes that it’s not as easy to make adjustments on the Kawi because there’s no ride-by-wire system. “It’s not like on the Yamaha where we can use the fuel for engine braking, but we can open up the primary butterflies by a degree or so and make it work,” he adds. The risk, of course, is opening the butterflies up too much and having the bike roll into the corner with enough steam to catch me off guard. Fortunately, this never was the case and Gardell proved a master behind the keyboard.

Daane’s comment regarding front-end feel is one that would be repeated ad nauseam throughout each trackday, as off-throttle front-end feel was a problem we wouldn’t start to resolve until we got to Chuckwalla Valley Raceway for my third and fourth day on the bike. The answer there came very surprisingly in the form of fork springs that we’d never tried before, but that’s a bit of what we’ve come to expect from the ZX-6R: for it to react differently to a setup than you would anticipate. Other chassis parts were less difficult to wrap our head around. The K-Tech fork and shock never had to be re-valved, for instance, and are still outfitted with the same damping specifications that K-Tech shipped the units with, which says a thing or two about the baseline settings on that company’s products.

The ZX-6R seems to launch well, and I managed to get the holeshot in our first race on the bike. Not pictured is Benny Solis Jr., a former AMA Pro Racing SuperSport West Championship contender, coming by when I proceeded to run wide into turn two.





The CVMA race weekend enabled me to get my head back in “race trim” and started Friday afternoon during a TrackDaz event that provided racers with an open session, great for getting reacquainted with the track in its clockwise direction. The next morning didn’t go exactly as planned only because the middleweight group’s qualifying session was cut short by a red flag and I wasn’t able to put in very many laps at speed. Everyone was in the same boat, however, and due to that I was still able to manage third spot on the grid in each of the two middleweight expert classes.

The first race provided an even greater confidence boost as I managed to get the holeshot in my first-ever drop of the ZX-6R’s clutch and lead into turn one. The lead was short-lived, however, as I got into turn two too hot (mostly out of excitement and amazement that I was even in the lead) and ran wide, ultimately giving the lead to Benny Solis Jr., a CVMA front-runner and past AMA SuperSport West Championship contender. Brian Short, another CVMA fast guy, pushed for second, but I managed to hold him off while just gradually losing sight of Solis up front. In the end I finished second and with a best lap time of 1:51.2, which was as fast as I’d ever gone at Chuckwalla though not as quick as I’d hoped to go.

Chuckwalla marked a turning point in the development of our project bike and was where we caught on to spring rates that’d solve setup problems. We’d leave with two trophies and a more positive outlook on the ZX-6R.





My second race didn’t get off to as good of a start. Actually it almost didn’t start at all, as I managed to ignore the loudspeaker and miss the warm-up lap altogether. Then, just as I did in the first race, I got into the turn one and two transitions a little hot, only this time I was worried about putting a bunch of input into the cooling tires and let Brian Short steal second place from me. And just like that, he and Solis were gone. I put more and more faith into the tires with each additional corner and ran the R6-mounted Short down in my best attempt to make a race of it, but it was too little too late, and I had to settle for third. A second- and third-place finish were welcomed, and we were pretty happy overall with the progress of the bike. Even better was that there was just a week to go before our Laguna Seca debut and the project bike was still in one piece.

That week was spent relaxing and focusing on my day job (wait, this is my job?), though Andrew Trevitt and I did spend time reviewing data as we’d been doing since day one using our AiM Sports’ Solo lap timer/data acquisition system. The study sessions seemed to be paying off, too, with Trevitt noting that I’d improved on trail braking a bit. Other aspects that we focused on were outright braking and consistency: “The upward spikes right at the beginning of the braking zones show how quickly you are getting on the brakes— that is really good. From there, what we want to see is the trace going back down to some small negative number, like -0.4 or -0.6, and staying there until the brakes are released. On your trace, there is a lot of up/down/up/down, showing a lot of modulation on the brakes,” Trevitt noted, suggesting that I smooth my riding out a bit, a point that I’d think about going into Laguna.

Our first day on the ZX-6R was centered on setting clip-on angles and the like, and then attention was turned to the shock link, which we’d experiment with throughout the next two tests.





I also tried to spend more time on the bicycle, riding between four and five days a week with the ultimate goal being able to make it through a full SportBike race without feeling completely depleted. Arguably, I should’ve started the regimen sooner, but I was hoping to be in moderate shape by the time we showed up to the track. And that’s not the only aspect that I managed to overlook in the early stages of this project, I’m sure.

As a matter of fact, I don’t think I realized exactly what it would take to make this project a success. Things came together nicely, though; the electronics were mostly sorted by this point and just need to be refined a bit, the chassis was headed in the right direction thanks to the setup we found, and the crew had a good game plan heading into the AMA Pro race weekend. Look for an update on that game plan in the third piece of this three-part story.

Resources

CycleMall Motorsports
(714) 258-7501
cyclemall.net

Flash-Tune Inc.
(888) 543-6302
flash-tune.com

Fastrack Riders
(877) 560-2233
fastrackriders.com

TrackDaz
(909) 234-4713
trackdaz.com

TrackXperience
trackxperience.com




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