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2010 Kawasaki ZX-6R Modified Comparison

Monday, July 12, 2010
2010 Kawasaki ZX-6R Comparison
Kawasaki did the modifications to its ZX-6R in house, using a majority of parts which are available from their performance parts catalog.
MotoUSA’s reigning Supersport Shootout champion comes into this comparison as the odds-on favorite. With no changes for ’10 with the exception of the BNG (Bold New Graphics) treatment (you had to know that was coming somewhere in this story…), the Kawasaki started with a target on its back, and for good reason. Not only does it make the most power out of the box, but it was also quickest in our ’09 Superpole session and picked almost unanimously by all testers in last year’s comparison. With ex-factory racing mechanic Joey Lombardo building the modified ZX-6R in house at Kawi, we suspected big things would be the result. Were they ever…

For Stage 1 Team Green aimed to source the majority of the go-fast parts from in the Kawasaki Performance Parts catalog. They opted for a Leo Vince SBK Corsa titanium full exhaust with titanium and carbon end can, while a Kawasaki kit adjustable ECU and wiring harness adapter where put in place and tuned to match the exhaust. As for gearing, the ZX-6R comes from the factory with a 520 chain. All Lombardo had to do was get new sprockets, those coming from
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2010 Modified Supersport Shootout Video - Stage 1
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Catch the Kawasaki ZX-6R in the flesh in the video portion of Stage 1 of the Modified Supersport Shootout.
Drive Systems USA, the chain remained stock. With the quick addition of a shim on the rear shock to add more forward weight to the ZX and mirrors removed the Stage 1 changes were complete.

If the dyno made one thing clear it was that once derestricted the Kawasaki makes some serious power. While all three of the others where within 1-2 hp, the ZX topped the entire field by more than 5 horsepower, turning the drum to the tune of 117.94 hp – a jump of over 12 hp from the 105.87 it made in stock trim. This gain was second only to the Honda in terms of improvement, as the CBR600RR gained just over 13 hp from stock. As for torque, this was much more in line with the competition. The ZX was just shy of the class-leading Suzuki in modified form at 45.97 lb-ft compared to 46.30 lb-ft, respectively, picking up a little more than three lb-ft over the 42.75 it produced in stock trim. In fact, all four 600s were extremely close in this regard, a range of only 1.06 lb-ft separating the entire field once modified.

The ZX comes into this shootout as one of the heavier stock machines, weighing in at 422 lbs full of fuel. Removing the stock exhaust helped out its cause, shedding 15 lbs in the process. Combined with the slightly lighter sprockets the end result was a ready-to-ride wet weight of 405 lbs, which was the heaviest of the bunch by a single pound over the Suzuki.
2010 Kawasaki ZX-6R Comparison2010 Kawasaki ZX-6R Comparison2010 Kawasaki ZX-6R Comparison
With the addition of a Leo Vince exhaust and Kawasaki's kit ECU, the ZX-6R was easily the undisputed horsepower king in Stage 1, pumping out 117.94 hp and 45.97 lb-ft of torque. Sprockets were sourced from Drive Systems USA.

As expected the Kawasaki’s engine was smack-you-in-the-face apparent from the first lap out of the pits. Strong throughout the rev range, once above 12 grand the beast came to life and left everything else floundering in its wake. Also the addition of the Kawasaki kit ECU gave an additional 1500 rpm of over-rev up top, extending redline from 14,000 to 15,500, something that didn’t go unnoticed. And the ZX would pull all the way to the limiter with no signs of letting off. Compared to stock the horsepower also peaks a full 2000 rpm higher, the base bike topping out at 12,200 rpm while the Stage 1 machine peaks at 14,200 rpm. Though while the engine was no question the ZX’s crowning glory, it also caused the bike’s low point during the second day of the test, which we will get to shortly. First let’s touch on the good stuff.

“The Kawasaki has hands down the strongest motor,” Sorensen remarks. “It has all the low-end power that you would want in addition to having a strong upper-mid range and the most over-rev of any of the bikes. The power has more noticeable steps than some of the other bikes, but feels like there is more acceleration, so it’s worth it.”

Neuer’s comments reflected those of Chuck’s. “The Kawi was super strong all the way through the power curve and the map was spot on,” he adds. “It’s just plain fast, making strong and usable power from top to bottom. It’s also not only the fastest but also one of the most forgiving if you make a mistake and lose revs.”

The Kawasaki is without question king of the motor wars, but as I alluded to earlier it showed some signs of weakness on Day 2 of the shootout. During our Superpole session on Sorensen’s out-lap, already nearly at full-tilt, wide-open down the back straight, the engine completely let go, seizing a rod bearing and blowing a hole through the case the size of my fist (that’s not an exaggeration in any way). Thankfully Chuckie was on the ball and as soon as he felt a vibration pulled in the clutch.

Despite it dumping out every last drop of oil instantaneously, much of it on the rear tire, Sorensen pulled off the save of the century and didn’t go down (he’s a former AMA champ for a reason). He then pushed the bike back to the pits and as the track was cleaned Lombardo, along with help from the Suzuki and Yamaha boys, was able to get the parts switched to the back-up bike and still made it in Superpole. Amazing stuff.
2010 Kawasaki ZX-6R Comparison
Yamaha and Suzuki both chipped in right away to aid Kawasaki in getting the back-up bike ready for Superpole after the original blew a hole in the case halfway through Day 2 at Streets of Willow.

Though the question quickly arose: How could a fairly stock bike with limited modifications have such an issue? Was it the additional rpms allowed by the kit ECU? Following the shootout Kawasaki went back over the damage and claims this was from a case (or cases) of mechanical over-rev, which happens most of the time when a rider downshifts improperly, pushing the motor past redline under deceleration, something the rev-limiter is unable to stop. Kawi believes this may have happened earlier in the test at some point(s) and weakened the engine in several areas as a result, adding that it had nothing to do with the additional rpms allowed by the kit ECU.

Whether or not this is the cause we have no way of knowing for sure. One thing worth taking into consideration in Kawasaki’s defense is that the horsepower and torque numbers you see here are from the back-up bike, as the dyno runs were performed following the track portion of the shootout. This shows that any new 2010 Kawasaki ZX-6R would more than likely be capable of these horsepower gains, and that the engine’s malfunction may have merely been a fluke. But we will let you be the judge.

One thing that was for sure was the Kawasaki’s well-sorted final-drive gearing. The 15/45 combination worked extremely efficiently at both tracks, providing good drives off the slower corners at Streets and easily pulling top gear down both the back and front straights at Big Willow. Much like the Honda, the ZX’s gearing was head and shoulders above the other two without making a single change at either track.

“Both the Kawasaki and the Honda were geared exactly where they needed to be,” says Sorensen. “The Yamaha and the Suzuki both ran five-speeds at the big track whereas the CBR and ZX would pull top gear without problem. Same held true for streets, as the ZX worked well everywhere and wasn’t between gears at all.”
2010 Kawasaki ZX-6R Comparison
Showa's Big Piston Fork on the front of the Kawasaki continued to receive praise on corner entry and mid-corner, though the bike's limiting factor is without question the stock shock.

Handling was a much improved area over its ’08 predecessor, thanks to the addition of Showa’s Big Piston Fork. This aided in corner entry and handling overall, though the ZX’s stock rear shock has always been a point of contention and weakness for the green machine – and the current bike is no exception. While one can push extremely hard going on the brakes, mid-corner and exit is limited by the rear end as one can only tune it to a certain extent without hampering the bikes abilities in other areas, making for a constant compromise, more so than some of the competition.

“I give the Kawi fork a high rating not just because of the feedback you get from it but also for the excellent adjustability you have in the settings, and that you can notice the differences when you change the clickers even the smallest amount,” says Sorensen. “Kawi used higher quality internals for this fork and it shows. Eventually the other manufacturers will apply the same thinking.”

As for the shock, Sorensen adds: “The rear moved around a bit more than some of the other bikes and was one of the limiting factors for the Kawasaki.” Neuer was on the same page, commenting that the "shock need a bit more preload or something, it was sketchy at the big track; lots of movement in Turn 5.”

2010 Kawasaki ZX-6R Comparison2010 Honda CBR600RR
With the exception of its strange engine issue on Day 2 of the comparison, so far the Kawasaki (above) and Honda have stood out as the front running pair so far.
Even without being able to get the shock perfectly set up, at Big Willow where motor is king, the Kawasaki came out on top with a best time of 1:27.36, four tenths ahead of the second-place Honda, which did a 1:27.75. As for Streets, the top two switched spots, with the Honda taking honors in front of the Kawi, 1:19.27 to 1:19.56, respectively. Averaging the two shows the Kawasaki just edges the Honda overall, though by less than a tenth of a second. Also consider that the bike which was ridden in Superpole at Streets was the back-up bike due to the first blowing up, on which no previous set-up had been done.

In regards to how it compares to last year in stock form the Kawasaki made one of the smallest gains in terms of outright lap times at Streets, dropping from a 1:20.23 (which was the fastest of the ‘09 test) to said 1:19.56, a gain of just under seven tenths of a second. This is still a formidable gain, however, especially considering how good the bike is in stock from. It did win last year’s shootout.

While this is only the first stage of our Modified Supersport Shootout and we won’t be determining a winner until all is said and done, one thing has become extremely clear – the more modifications we add the closer these bikes get. With the exception of the Kawi’s hp numbers, all the bikes spun the dyno within a couple hp. On track things were even closer, as the gap in lap times at Big Willow was just over seven tenths of a second and at Streets it was a hair over one second. This compares to a gap of almost 1.8 seconds at Streets during the stock shootout last year.

From here the bikes get upgrades to the suspension and brakes, plus a speed shifter, rear-sets and clip-ons, turning each of them into full-fledged trackday weapons. The Kawasaki and Honda proved strong so far but will the addition of more mods help put the Suzuki and Yamaha pull back into contention? Or will the gap get even larger? Stay tuned for Stage 2 to find out.

2010 Modified Kawasaki ZX-6R Gallery
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stefaan -great article  September 27, 2010 06:20 AM
you guys sure know how to keep our attention: i don't think I've ever found a modified comparison!! 1 small sidenote, as mentioned before, the gsx-r 750 is left a bit forgotten in your (not only yours) articles. it is a sportbike that a lot of riders own, or would like to own, and i miss a bit of good quality articles.
HRC -KID blade  September 11, 2010 08:01 AM
I will hAVe the KID Blade(600RR) any day.GOD bless HONDa
Mark -Great article.  August 1, 2010 02:29 PM
Great article, as the others have said. You covered all the bases and coverd them well. Nice work and thanks!

I'd like to see how the GSXR750 compares to this bunch.
MAX -Great article  July 18, 2010 06:44 PM
Just plain great. Tons of detailed info, great pictures, lots of relevant data and comparisons. Great job.

Now, could you please lay over (for each bike) the stock hp and tq graphs with the modded hp and tq graphs? We got the peak numbers, but I would like to see how these changes affect the curves lower in the rev range. Also, dragstrip (1/4 mile) numbers would be nice.
Scott R -Kawi?  July 17, 2010 01:19 PM
Funny how Yamaha is the 1 fixing the bike after the Kawi motor blew...
1198freak -good test  July 16, 2010 12:19 PM
Now why dont more moto mags do comparisons like these? They only compare stock bikes, that's useless because I bet that at least 80% of sportbike owners mod their bikes with at least an exhaust and power commander, and every trackday rider I know mods their suspension and/or chassis as well. Who keeps their bike stock? This article is much more relevant than the usual magazine comparison article to the average sportbike rider.
spectator -w00t - MODS!  July 16, 2010 11:36 AM
this article is awesome for a few reasons; one, no new s**t is coming out (in the 600 class) because of financial turmoil, and subsequently, motojournalism recently is BORING AS HELL (this is not). Two, HUGE props to Atlas and Sorensen for being the testers, because they're both 10x more awesome at racing bikes than the rest of the "i'm a baddass moto-journo" crowd. Three, it shows just how capable these bikes are in stock form; and totally dissuaded me from going the mod route on my own 600. I need to spend 2000.00 on tires (maybe brake pads) and track fees, not mods that even AMA champs can only get 1 second from. Other comments - if the only minor lap improvement wasn't enough, grenading the ZX6R's engine is a perfect reason not to go engine mod crazy on your bike. I like that barring egregious abuse, stock 600's are fairly bulletproof. I definitely don't have the resources to "source an extra bike" to finish a track day. Or maybe Kawasaki's really are built just a little bit shittier than hondas & yammies. Awesome work, can't wait for the next chapter! Secretly though, I want to mod my 600rr down to around 340lbs but that will need a custom subframe and carbon rims...!!!
ohio -Can't please everyone...  July 15, 2010 06:07 PM
I think this is a great concept and so far a well-written article. Moto-USA continues to impress me of late. If it were my money, I would have pumped that initial $3k into shock and cartridges BEFORE engine mods, but I still think it's a reasonable approach and in sum it will be valuable info to me. Surprising is how much the R6 seems to be lagging behind when it still seems to be the racer favorite and class leader at actual track events. Agreed that it would be interesting to have the 675 (and even 848) in the running.
Frank -Moto USA Please explain  July 15, 2010 05:45 PM
Raising the redline of an engine by over 10% without any fortification to engine internals and beating it up on a track day for a head to head shoot out will likely bring about unhappy results for everyone. But what I find to be most interesting and confusing is in the “2009 Supersport Shootout VII” the stock Kawasaki ZX6R made 105.87 hp @ 12,200 rpms…but in the “2009 DSB Comparison” a stock Kawasaki ZX6R made 108.3 hp @ 14000 rpms. That’s a 1,800 rpm difference in where it makes peak hp!! Unless the dyno were the bikes were tested is made by Fisher-Price I would say that is a huge gap or difference. Plus, the modified Kawasaki is making its peak hp at 14200 rpm…go figure.

“Also the addition of the Kawasaki kit ECU gave an additional 1500 rpm of over-rev up top, extending redline from 14,000 to 15,500,” If allegedly according to your DSB shootout the Kawasaki makes its peak hp @ 14000 rpms, (which I’m sure it does because that is around the same magic number all the other 600s in stock form are making peak hp), then how can the Kawi have a redline of 14000 rpms? Is the rev limiter going to slam on at the same time it is making peak hp? Besides every 600 always has a little over rev after peak hp. Also, even the 1999 CBR600 F4 revs to a redline of 14000 rpms.

I think you guys have some explaining to do.
Bob -eab  July 15, 2010 01:35 PM
“Guess my age is showing, eh?” Nope just your ignorance and it is showing quite well!
Karlson -gunter  July 15, 2010 10:19 AM
“there are still (a lot) of people who ride on a track in a specific class and use mods like these. So bringing a 1000 to a 600 race is no option.” I fully agree gunter and that is why I validated my post by writing “600s are great bikes but unless you NEED the extra hp because you are racing these mods are a waste of money.”
Karlson -EAB  July 15, 2010 10:13 AM
Only a sex deprived geek can read a statement “If you want to look and sound cool,” and try to connect it to shortcomings and Viagra. EAB, if some people did not think louder exhaust equates to “cool” then there would not be a mega million dollar after market for it. Read my statement carefully. I wrote “if” “you” want to look and sound cool. I did not say you will look or sound cool, although any sport bike looks and sounds better with the stocker removed.

Apparently my point was lost on you EAB so I will break it down for ya. A rider can spend $200 dollars on a slip instead of a full exhaust and ECU and still superficially have the “look” and “sound” of a race bike but have not spent as much $$$. Instead they can spend the money not spent on the intake and exhaust mods and upgrade tires, brakes and so on. My post actually advocates to not even bother with the exhaust at all but cleverly included a simple cost effective solution for those who need the sound of a loud exhaust.

“Harleys and sportbikes waking me up at 5AM pisses me off.” I never said anything about Harley’s loud exhaust and maybe you’re pissed off because you are in bed and they are out riding or that you trailer home has real thin walls.
will parker -motorcycle noise..  July 15, 2010 08:43 AM
EAB, Harleys w/straight pipes are WAY louder than supersports..a 600 w/an aftermarket pipe is the best sound in all of motorcycling..
EAB -Karlson comment  July 15, 2010 05:52 AM
I would debate that the slip on makes one look and sound cool. Obnoxious and disrespectful of others maybe, but not cool. Guess my age is showing, eh? Harleys and sportbikes waking me up at 5AM pisses me off. If one needs the self confidence boost of a loud exhaust to compensate for "shortcomings" then perhaps therapy or viagra might be a better move.
gunter -for track not for street  July 15, 2010 04:00 AM
While I completely agree with Karlson about the prices of these upgrades, there are still (a lot) of people who ride on a track in a specific class and use mods like these. So bringing a 1000 to a 600 race is no option. It'sinteresting to see what mods give what benefit at what price. Then it's up to the owner to decide what's worth it.

Looking forward to the next shootout :D
samxrl -It's about time  July 14, 2010 08:29 PM
It's about time someone did a comparo using bikes that are being modified. I agree with Karlson that most of the mods cost too much and one can get a bigger bike for the same price. I'd advocate getting more experience with riding situations (Keith Code or Kevin Schwantz racing training schools)to better use their bikes' abilities. Having a track nearby helps too.
Karlson -Money spent  July 14, 2010 06:20 PM
Spending nearly $2,000-$2,500 on an exhaust and EFI/ECU mod for just 10 hp over stock is just stupid! For that much more $$$ you can just get a 1000cc and be done with it. Or if you want a more nimble bike just buy a 750cc and have more hp and torque than any of these 600s regardless of mods. 600s are great bikes but unless you NEED the extra hp because you are racing these mods are a waste of money. How many sticky sets of tires (things you NEED) could you buy with $2,500.

If you want to look and sound cool, get a slip on and dump the other $2,300 into tires, suspension, brakes and so on. Besides most of your lap time improvement will be made up getting into the corners (hard braking, line choice setting up the exit), the speed trough the corners and of course corner exit. The biggest impact on these maneuvers will come from good suspension set up/components, strong brakes with good feel and of course fresh tires. Once you get those issues sorted out then go ahead and play with hp.
Quick10 -I don't know  July 14, 2010 04:38 PM
The rev extend is usually used on built motors. I know with the Power Commander you have to send them a list of engine mods to get the code to unlock the additional rev's. With that said Kawi motors are pretty bullet proof. It might be a combination of them pushing it a bit with the extra revs and the rider over reving the motor on downshift like the article says. One thing I really noticed was the price difference in the upgrades.
unclewill -I say...  July 14, 2010 01:24 PM
...once it blows up, it's out of the running.
TG -EAB - Pro's don't blow stuff up?  July 14, 2010 12:48 PM
While I agree with most of your statement (sans Red Kool Aid remarks), I've seen more pros blow stuff up than amatuers - in every racing series. Sometimes you can attribute that to the high-strung nature of the true race bike (ex. WSBK, WSS, etc.); but, in other series where pro doesn't mean factory bike (like MotoX racing) you see pros with grenaded motors a lot more often than the weekend warrior. Simply put, the pros are doing it for a living, and will ride the limiter if they think it will help - your weekend warrior won't do that to his/her machine.

That said, it is still really hard to swallow that line from Kawasaki that some over-rev downshifts weakened the motor to that extent. Is it the one in 10,000 to have the problem? Or is that trick race ECU with extra over-rev to blame? Kawasaki would be the one to know, but what would they want published?
EAB -I dunno about that...  July 14, 2010 11:46 AM
I think Kaw's excuse for the engine letting go is suspect. Honda has done many years of walking the line between reliability and performance, and the fact that with all of their resources Honda's power is that far off of Kaw makes me think Kaw may have pushed it too far. It will be interesting to see if Kawasaki let's the 15,500RPM and state 1 as installed continue. The same guys rode the bikes and none of the others put bits all over the track. These guys are pros, and not prone to blowing stuff up.
will parker -modified 600s.  July 14, 2010 11:39 AM
surprised the two years older designed Honda did do well against the Kawi..newer is almost always better in Japanese circles...
600s 4 Life -Finally  July 14, 2010 09:41 AM
At least one of the pubs didn't totally overlook the 600s this year just because none of them are "all-new". Cool concept too. I'm looking to put an exhaust and do suspension stuff to my new R6 and it was cool to see the dyno charts and what differences it made. Keep it up guys!
TJ -kawi  July 14, 2010 07:12 AM
ive heard the 07 08 zx 6rs are having some engine problems, hope its not a reoccurring things and a 675 wouldve been sweet in this group
Lee -I agree.  July 14, 2010 06:11 AM
It does suck that the 675 is such a black sheep, maybe Triumph didn't have enough resources to get a bike to them?
Vince XB -No Daytona?  July 14, 2010 04:52 AM
No Daytona 675? Shame.