How fast?

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mattyv74
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How fast?

Post by mattyv74 »

corbywan wrote:How fast is red line in top gear on the 7R?

Not exactly sure. I have hit the limiter (13000rpm) in 6th tucked in behind Scott's 9. I think the speedo read in excess of 265km/h, can't tell for sure, the needle vibrates all over the shop at that pace. Plus, there're much more important things to worry about :roll: Taking into account the happy speedos that the 7's all have, I guess it's about 255-260.
Any body know of any actually recorded top speeds?
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re: How fast?

Post by Bluefly »

Put a pillion on the back (not me) and give them a digital camera. Proof!
:)
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mattyv74
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Re: re: How fast?

Post by mattyv74 »

Bluefly wrote:Put a pillion on the back (not me) and give them a digital camera. Proof!
:)

As you know, at 230 isn't easy to hang on. How do you propose we manage high 2's? With a camera :?: Apparently I don't provide alot of shelter. :lol:
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re: How fast?

Post by mrmina »

gaffa tape it holds anything together and fixes everything.
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re: How fast?

Post by plane »

A lot of guys in the 'States run a hand held GPS. Some of them have top speed functions as well as total distance functions.
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Re: How fast?

Post by Smitty »

mattyv74 wrote:
corbywan wrote:How fast is red line in top gear on the 7R?
Not exactly sure. I have hit the limiter (13000rpm) in 6th . I think the speedo read in excess of 265km/h Taking into account the happy speedos that the 7's all have, I guess it's about 255-260.
Any body know of any actually recorded top speeds?


Matt
I have been through all my printed stuff on the 750's
from the Gpx to ZXR750's to the last ZX7r
lots of notes about high rpms (we know they luv to rev)
but only one Kwaka brochure mentioned a top speed
and that was on the GPx brochure.
It said that at the redline (11500rpm) the top speed was 248kmh
thats with a 140/70 V18 rear wheel and standard gearing
now....
I rev mine in lower gears to over 12000 and I also know Tim
revs his up to 14000 (and Kawasaki state in the Racing Appendix for the
Gpx that engine speeds in racing up to 14500 are permissible)
so
Top speed could be higher, given a long enuff runway!

At my first ride day at PI, there were some guys there
with a radar gun and they were clocking everyone (unofficial of course)
I got clocked at 248 just as you entered turn1
so i guess Kawasaki are correct!
(mind you the thing was still accelerating...slowly)
really
the only way to do this is mathematically
unless someone wants to chance their licence ..and a BIG fine
besides speedos aren't accurate and are you going to watch it at 260?

so how?
you need
rear tyre (on wheel) circumference (wrap string around it and measure that)
and rear sprocket gearing (front teeth to rear teeth ratio-count them)
and pick engine revs..say 12000 or 13000
so
an example
rear tyre circumference is 750mm and sprocket teeth ratio is 1:3
(16 teeth to 48 teeth), so at 12000rpm
the rear wheel is going around 4000 times a minute
and it will cover 3000 metres a minute (circumfrerence by #turns)
and multiply by 60 (for an hour)
= 180000 metres an hour = 180kmh/hour

does that help?

cheers
Last edited by Smitty on Fri Sep 17, 2004 11:52 am, edited 1 time in total.
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Re: How fast?

Post by Nanna10r »

mattyv74 wrote:snip...Not exactly sure. I have hit the limiter (13000rpm) in 6th tucked in behind Scott's 9. I think the speedo read in excess of 265km/h, can't tell for sure, the needle vibrates all over the shop at that pace. Plus, there're much more important things to worry about :roll: Taking into account the happy speedos that the 7's all have, I guess it's about 255-260.
Any body know of any actually recorded top speeds?


ZX-7R ('00) 6/00 quatermile 10.92 @ 127.4mph 60-80mph in 4.07
80-100mph in 4.22sec 158.1mph top speed
from http://www.sportrider.com/bikes/146_perf_nums/#kawasaki
Thats a lot of force movement right there .. could be a shift coming on ?.
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re: How fast?

Post by Thundabird2 »

How fast? Fast enough I'd say. 8)
I don't want to sound like an old man, but you are doing this on a track aren't you? :shock:
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re: How fast?

Post by MadKaw »

On my ZX7R with one tooth down on the front sprocket, I was redlining in 6th at Eastern Creek with a speedo reading or around 250-255.. There is probly a speedo error of anywhere from 2 to 10 % (real speed would be less)

I believe the quoted top speed is about 270...
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Re: re: How fast?

Post by mattyv74 »

MadKaw wrote:I believe the quoted top speed is about 270...

Hmmmmm...coool. Only about 30km/h to got then.
So to get 300k, how much hp do you think I'll need? :shock:
Without a tow from a bigger bike, the little 7 won't quite hit the limiter in 6th, so hp is a limiting factor. So the engines are basically safe to 14,000rpm? I'd prefer to rev the engine out rather than change sprockets and compremise grunt down low.
I believe there is a mod that can be done to bipass/switch off the limter. Does anybody know about this? My (good) housemate is an alactronics engineer, so he can modify any of the printed circuits etc... We just need the info.
Of course, to make use of higher revs, the cams will need to replaced, re-dialled or reground and carb size increased or atleast rejetted.
No real urgency here guys, just shooting the breeze really. 8)
Last edited by mattyv74 on Fri Sep 17, 2004 11:35 am, edited 2 times in total.
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re: How fast?

Post by mfzx6r »

Matt
I have a camera/vid mount for my 6 it may fit your 7 if you want

It uses the two front tank bolts and sits over the tank area

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Re: re: How fast?

Post by Smitty »

MadKaw wrote:On my ZX7R with one tooth down on the front sprocket, I was redlining in 6th at Eastern Creek with a speedo reading or around 250-255.. There is probly a speedo error of anywhere from 2 to 10 % (real speed would be less)I believe the quoted top speed is about 270...


Dave
Can I suggest you use the maths method
this will give you an accurate speed
do you know..??
the number of teeth on front and rear sprcokets
('course you do)
the redline? ..is 13000??? 12000?
and your rear tyre circumference ?

supply them figures
and it will take about a minute to calculate your warp speed factor :lol:

cheers
Last edited by Smitty on Fri Sep 17, 2004 11:53 am, edited 1 time in total.
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Re: How fast?

Post by Thundabird2 »

Smitty1955 wrote:the only way to do this is mathematically
does that help?

cheers


Hi Ian. Just looking at your formula for calculating speed. I won't quote the entire essay :!: , just thought I should correct the use of diameter, not circumference. You'd use diameter to calculate the circumference using pi.

Just sneak back and edit it. :lol: I won't tell anyone.

The formula is good, but I'd guess that at that speed the needles would vibrate an awfull lot making it pretty tough to get an accurate figure.
I'd say he should be watching the road/track rather than the tacho at that speed!
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re: How fast?

Post by Quarkz »

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Re: re: How fast?

Post by Mizz ZZR »

mrmina wrote:gaffa tape it holds anything together and fixes everything.

Gaffa tape is only good to 200kph. A couple of my friends have proven it...

Oh and nose rings go flyin at 200 too.... :P
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