June Motorcyclist - full test of ZX12R

[Guest]

Mal, my buddy juan just did 196 via gps yesterday on his red/grey 2000. He recently installed a yosh full ti duplex.
Maybe you know him. Were up in palm beach. I would like to ride sometime and have no problem going south. Maybe richard could join us. Mail me if this is possible.

omegaltd@gateway.net

 

[Guest]

We wont know shitt till he's able to start twisting her tail.

 

[OB_Busa1300]

Sorry but Copper is the fastest!

 

[OB_jeffw]

Restriction via a magical "[insert your fav color]" wire is quite crazy. I'm sure they would prefer to mess with the fuel mixture or iginition timing up at top withn the ECU.

Then "beating" the limit would be just installing a pc2........hmm please the establishment & the speed freaks, what an ieda

 

[OB_Utah Rider]

I've also used a GPS to determine the inaccuracy of the speedometer. My Garmin GPS III keeps track of the top speed. Are GPS really accurate to .1 mph? Why don't magazines use a GPS to test top speed? Wouldn't that be more accurate than radar since top speed may occur before or after the radar was used?

 

[OB_JohnC]

I've used my GPS III+ in the car. I don't think it's within .1 mph, though it is close.

I'm not saying my car is correct, but I think the car is consistant. 70mph indicated is always the same actual speed. 70mph on the car doesn't always get the same reading from the GPS. The GPS varies 1 to 2 mph. So the GPS should be MUCH better than the Bike's spedo for an actual reading

I haven't used it on the bike(while moving). Where do you put it?

 

[OB_c.dolan]

"Restriction" not all that complicated. I tested for actual measured vs indicated on speedo. Actual measured speed in 6th gear, with OEM 18 : 46 sprockets is 93 mph @ 5500 rpm. That would be equiv. to 186 mph @ 11,000 rpm. Probable peak horsepower peak would be at, or below 11,000 rpm............................... ...Speedo read 100 mph, when actual was 93 mph.

 

[OB_scotty]

Civilian GPS has an error factor built into the software. This might lead to errors in indicated speed. Only the military has access to the uncorrupted version.

 

[OB_Mr Bear]

Redelk had a GPS on his ZX-7. It's a good idea, don't know why magazines haven't used it. The way the system works, the computer needs to "find" two satellites to shoot bearings from, before it starts to give an accurate speed number. Once it finds three, it is reading very accurately. The network of satellites they use is pretty extensive; a gps unit can usually find a dozen or more fairly quickly.

There are other places that error can come in, other than the ability of the system to take accurate bearings (and therefore give accurate speed readings). But they do have the ability, technically, to be very accurate.

 

[OB_Mr Bear]

Where'd you hear that, Scotty? Doesn't seem like Garmin building an accurate GPS would exactly threaten national security.

 

[OB_Mr Bear]

I mean, there's lots of civilian/non-military applications where precise positioning & velocity readings would be not just helpful, but necessary. General/civil aviation; merchant and large private seagoing vessels, are examples where safety would only be enhanced by highly precise positioning. I think the quality of the measuring device is also what makes the good ones pricey, besides just the FAA stamp of approval.

[This message has been edited by Mr Bear (edited 18 April 2000).]

 

[OB_Mis4tun81]

In scotty's defence I always understood Handheld GPS units are built with limited accuracies, and slow refresh rates, because of the "ease" they could be incorporated into a homebuilt missle by terrorists with the GPS receiver as the brains to guide the missle to a pre-programmed target.

Because the signals transmitted by the GPS sattalites can be used by everyone friend or foe. They build the error into the equipment that is avaliable to everyone.

It also seems to me pin point accuracy is subjective, 200-300 yards seems pretty acurate for an ocean going ship, however if you have ever wandered around the woods at night you know you would need +/- 10 feet just to find your tent.

I also know that at our best my freind and I can paddle his canoe at 6 MPH (according to his GPS)

L8r

 

[OB_Ivan]

Hi Guys, my name is Ivan,
I am a shop owner, who owns a dyno, a 180hp 'busa, a 160hp R1, a 144hp 9R, many of you may know me from the YZF-R1 Forum.
I have tested with equal weight riders, both the busa and 12R, under controlled conditions in a 2nd thru 5th gear roll-on, (not enough room for 6th).
I have also dynoed them both on the same day, (1hr apart),2000 busa (159.8), 12R (161.9), both bikes were 100% stock, and both bikes are essentialy a dead heat.
The dyno charts are on the YZF-R1 forum.
There will be more testing on this topic, my friend who owns the 12, has seen 12,000rpm in 6th, on the road.
On the dyno, theoretical top speed at the rev-limiter is 194mph, the revlimiter cuts in at indicated 12,400 on the tach, andin reality the revimiter cuts in at 11,750rpm.
Ivan

 

[Guest]

Good to have you here Ivan, your input is valued and appreciated. Keep it coming.

 

[OB_scotty]

WHY DO GPS UNITS HAVE A BUILT IN ERROR.

All GPS units from all manufacturers have a design positional accuracy of 15 meters.

The GPS satellites are owned and controlled by the U.S. Department of Defense (DOD) and this agency has the prerogative to degrade the accuracy of the GPS signal available to non-military users for purposes of national defense. This is done by what is called "Selective Availability" (commonly known as "SA"). SA is normally turned "on."

SA allows the U.S. DOD to degrade the accuracy of non-military GPS system by as much as +/- 100 meters. At the present time the accuracy of all commercial GPS receivers can vary Between 15 to 100 meters depending on the level of degradation being imposed by the U.S. DOD.

SA introduces a positional error which changes over a period of time.
Another factor that will effect the accuracy of the GPS receiver is the geometry of the satellites in view to the GPS receiver. A poor geometry situation can provide less accurate position readings, and this especially applies to GPS altitude measurements.

The altitude reading on the GPS unit can vary by +/- 450 ft. depending on the level of degradation being imposed under SA. It is not uncommon to see the altitude continuously drift up and down when SA is being imposed.

Any other GPS questions grasshopper?

 

[OB_Mr Bear]

thanks, Mis4tun...

Understood, and it would be relatively simple to limit the accuracy of a gps unit in the software by not allowing the processor to triangulate bearings too precisely. The solution for a rider wishing to measure speed (or a dictator building a "homebuilt" missile too, for that matter) would be to read from 3 or 4 units at the same time.

That would give you "ball park" data points, and the average number would be very accurate. If there is a "single error factor" programmed into the software, as Scotty implied, that would require a different approach. Someone would have to have the capability to decompile and alter the processing software.

The determined missile-building dictator could probably do it, but it would be a major challenge for the average sportbike-owning speed freak. I bet a few of the more geek-ish members who post on these boards would be able to do it, though. There are some brains here.

 

[OB_Mr Bear]

Cool, Scotty! Just read your last post. It's not a 'Young Grasshopper' situation, more like being 15 years out of date on my info. I used to be privy to the best Uncle Sam had to offer, but since then I haven't even bothered to try to stay on top of it.

Sooooooooo.....
When is the Busa ride to LA gonna happen?
C. Dolan now has a green ZX-12, and is in need of harrassment by a couple of Busa riders. We're just the guys to do it.

 

[OB_scotty]

I would be up for a ride this weekend. Bastards have me working nights for the next three weeks. short nap on sat. morning and I would be ready to go. Lets do it.

 

[OB_scotty]

One last note on accuracy. The GPS theoretically would be very accurate with a link to just three satellites but the timing becomes the weak link. (the satellites all have atomic clocks on board, our hand held GPS does not). To minimize the timing issue the GPS often links to four or more satellites.