Power Broker
How does the new ninja perform on the dyno and drag strip? Rickey Gadson helps us find out.
No one knows more about hustling sport bikes-Kawasaki sport bikes in particular-down the drag strip than Rickey Gadson. The winningest rider in AMA/ Prostar history has essentially become the face of American drag racing thanks to his high profile relationship with Team Green. When we wanted a rundown on the new ZX-14's ultimate straight-line potential, we went straight to the source-and Sicklerville, new jersey's, Sultan of the Strip was happy to oblige.
"When I first got on the '08 ZX-14 back in August, I was shocked-it looked the same, but was so much easier to ride fast," Gadson says. "The new bike accelerates quicker anywhere you hit it, especially in the low revs and midrange. you whack the throttle on and it picks the front wheel right up and goes!"
Kawasaki didn't necessarily squeeze more horsepower from the 1352cc four-in fact, the '08 ZX-14 we tested actually made fewer peak ponies than our '06 testbike, producing 167.2 bhp at 9250 rpm versus 175.7 at 9550. This power loss can likely be traced to the more restrictive, Euro 3-spec exhaust with its third catalyzer, and possibly an overly rich fuelinjection map. More on that in a minute...
What Kawasaki did was greatly improve low-end and midrange power, something that was decidedly lacking on the previous generation ZX-14. For whatever reason (fear of liability lawsuits?), power output on the old bike was significantly restricted at lower revs in lower gears. Adding a simple Ivan's Timing Retard Eliminator ($70 from www.ivansperfor manceproducts.com) to the '06 ZX-14 would produce a 13-bhp gain at 4000 rpm. Some tuners would even remove the secondary throttle butterflies (the opening of which was delayed at lower rpm by the ECu) for even more low-end power gains.
It appears that Kawasaki made similar changes as part of the '08 revision. Though these aren't the sorts of things manufacturers' reps openly comment on, we've heard off the record that the secondary throttle plates open more quickly on the '08 bike, and the press kit does mention a mysterious new Digital Timing Advance. These changes, along with improved intake porting and new, finer-atomizing fuel injectors with an increased lateral spray angle, together make the '08 model quicker and faster than before.
How much quicker? Gadson's best E.T. on a first-generation ZX-14 was dispatched in 9.75 seconds at 147 mph. His best so far on a 2008 model? That would be 9.65 seconds at 148.24 mph.
As noted, Gadson reports it's easier to go faster on the new bike, too. "The new bike makes more torque down low," he explains, "so instead of using rpm to rocket off the starting line, I can drive off at a really low rpm, get the clutch out quickly and roll into the throttle right behind the clutch. At 3500 rpm I've got 85 lb.-ft. of torque-plenty to drive off hard and get into the throttle early. leave at higher revs and you can forget about it: At 4500 rpm, the front wheel will be in the air by the time you get the clutch halfway out.
" Just don't wait too long to shift, Gadson cautions. Though acceleration is greatly improved at low revs, an overly rich factory fuel-injection map sabotages high-rpm performance. Power literally plummets past the 9250-rpm horsepower peak; by the 10,750- rpm redline, our '08 ZX-14 was making just 153 bhp-a dramatic, 14.2-horsepower drop. The exhaust-gas analyzer revealed that the air/fuel ratio falls to nearly 10.5:1 at redline, far from the optimal 13.8:1.
We can only speculate why the bike is mapped so rich on top. It could have something to do with emissions (though we can't imagine why it would be richer rather than leaner), or it could be a CyA measure to prevent grenadine when ninja joe tosses on a free-flowing aftermarket exhaust and doesn't bother remapping to suit. Either way, installing a Power Commander and leaning out the mixture could be worth as much as 10 or 12 bhp at the top of the rev range, and would almost certainly give the ZX-14 a few more mph at the far end of the drag strip.
OK, but how does the ZX-14 stack up against its arch-nemesis, the Suzuki Hayabusa? Dragstrip-availability issues prevented us from staging our own duel between the two, but we did crib notes from a well-known drag-racer who did just that (and who insisted on anonymity, due to sponsorship obligations). The two bikes were bone-stock, including tires and gearing, except that each was lowered with a fork tie-down strap and an aftermarket shock link. Twenty passes on each resulted in a virtual stalemate: The racer's best times were 9.24 seconds at 150.0 mph for the ZX-14 and 9.23 at 151.5 for the 'busa. "Almost identical," he said. "If you just glanced at the time slips, you'd think I ran the same bike 40 times."
They're that close.