posted January 09, 2011 10:33 PM
Edited By: fish_antlers on 10 Jan 2011 06:33
it is odd that they sat on the article for 2 months - dont you think? I mean - didn't that launch and ride happen in October?
____________ What business is it of yours where I'm from, Friendo?
quote:it is odd that they sat on the article for 2 months - dont you think? I mean - didn't that launch and ride happen in October?
Probably held it as a "COURTESY" to Kawasaki.... Or maybe they just wanted to take thier time to ensure that the information they put out is factual and not heresay,conjecture or cry baby bullshit..... who knows? good article anyhows.... check out the wheelie control in action
quote:The long mystery sales hold on the 2011 Kawasaki ZX-10R is scheduled to end in late January, and the company has given an explanation for the holdup: the possibility of intake-valve spring surge (coil vibration) under what Kawasaki calls “unique riding conditions, such as on a racetrack.”
The intake camshaft, valve springs and spring retainers of new ZX-10Rs will be replaced to eliminate this possibility, “without affecting engine performance.”
Computers are wonderful tools, but physical testing continues to be essential for critical performance areas, such as valve-train stability. Valve-spring surge is the rapid bouncing of a wave of compression from one end of the spring to the other. It is excited by very rapid cam acceleration. Surge results in a swift variation in spring pressure acting against the spring retainer, which is fixed by a pair of tapered collets to the end of the valve stem. This pressure variation can result in the valve’s failing to accurately follow the cam contour, or, as Kawasaki’s press release words it, “The surge could cause the intake valve to seat improperly.” Improperly means hitting the seat at too high a speed, leading to bouncing and damage.
Every manufacturer must deal with the possibility of surge, beginning with a computer model, moving to rig and dyno tests, and finishing with road and track mileage. Spring surge is very speed dependent, so much of an engine’s defense against surge comes from the fact that, in track use, rpm is constantly changing—never holding constant at the one particular speed that makes surge most likely. I suspect that Kawasaki discovered a possibility that surge could develop if rpm were held at one particular high and constant value, and decided to withhold the machines from sale until even this possibility could be eliminated.
The new cam may be subtly reshaped to suppress surge, the new springs may have a different natural frequency and the new retainers are most likely required because the new valve spring length is somewhat changed. All these changes can be accomplished without affecting engine airflow—or, as the Kawasaki release says, “without affecting engine performance.”
People are expecting a lot from this new ZX-10R on both street and track, which motivates Kawasaki to ensure that they are not disappointed.
____________ What business is it of yours where I'm from, Friendo?
posted January 13, 2011 07:53 PM
Excuse me while I hand wave a tiny bit at what I wrote in October;
--
“...Time for a little reality check, BMW knew they couldn't develop a big power advantage over the Japanese without using a far bigger bore than the Japs were, and revving it higher with superior compression and gas flow.
Power = air + fuel (mixed) and combusting at 11.8:1 ratio.
So if the ZX-10R compression ratio rose from 12.9 in 2010, to only 13.0 in 2011, but the bore and stoke remained identical while revs rose 750 rpm then all the engineers really had left was to improve the ventilation and chamber filling, mixing and extraction. So I would not expect any more than about ~15 hp or so more power than a 2010 model. Look at these basic numbers.
2010 BMW S1000RRR 999cc
Bore/Stroke 80.0 X 49.7 mm
Compression Ratio 13.0 to 1
RPM 14,000
2010 ZX-10R 998cc
Bore/Stroke 76.0 x 55.0 mm
Compression Ratio 12.9 to 1
RPM 13,000
2011 ZX10R 998cc
Bore/Stroke 76.0 x 55.0 mm
Compression Ratio 13.0 to 1
RPM 13,750
Clearly the induction and exhaust differences are DEFINATELY NOT going to put the Kawasaki in front of the BMW in max power. Sorry, but I betcha I'm right, there are no magic unicorns in Autopolis.
So don't let blurb derail logic as this will surely not be a 197 RW-hp machine in show-room trim, anywhere, it'll predictably be a 180 hp bike, because that's about what you could expect from unaltered bore and stroke and similar compression on premium fuel. You can't get around that reality. What Kawasaki are now doing (I think) with the Canadian power figures, is to start to deflate some of the unrealistic expectations Kawasaki's first-class bullshite (marketing) dept has now inflated. They stimulated interest with a fantasy, and now they have to manage and shape the approaching reality.”
I still don’t buy the story that Euro models make so much more power, they won’t.
Fark,185 ponies. And look at the wheelies this thing pulls, the BMW won’t do that with all the gizmos still turned on. What's not to like here? 5 or 10 horses in the top, and 1/10th more or less down the quarter means shit to me. If you want faster, get a quickshifter plus eat less pies.
____________
Natural selection always gets it right over time, and you are the byproduct of about 4 billion years of it, so do try not to prove it wrong ... mmmkay?
posted January 13, 2011 09:48 PM
BTW fish, it's already Friday arvo here, so have a good weekend.
____________
Natural selection always gets it right over time, and you are the byproduct of about 4 billion years of it, so do try not to prove it wrong ... mmmkay?
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posted January 07, 2011 01:18 PM
She handles........ 
posted January 08, 2011 10:57 AM
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