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Jim McMahon
Joined: 07 Apr 2007
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Location: United States, St. Paul,
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 Posted: Fri Oct 19, 2012 10:26 am Post subject: Anyone got some KZ\ICC Dyno Charts? |
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Playing with some "optimal shift point" math and curious if anyone has a dyno sheet for any make/model of KZ motor. Not looking for the "peak" figures, looking for the torque curve..
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Mike Goebel
Joined: 28 Jul 2001
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Location: United States, California, Winnetka
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| Posted: Fri Oct 19, 2012 6:20 pm Post subject: |
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I did that once for a spec moto
2nd 11,900
3rd 11,800
4th 11,600
5th 11,600
6th 11,500
Mike G.
No one shifts that low though 
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Jim McMahon
Joined: 07 Apr 2007
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Location: United States, St. Paul,
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| Posted: Fri Oct 19, 2012 9:57 pm Post subject: |
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I did a CR125 as well based on the "Spec 04" curve from John Denman.
1-2 13,250
2-3 12,750
3-4 12,750
4-5 12,250
5-6 12,250
I calculated based on torque applied at the motor sprocket. Seemingly the jump from 1-2 is so big you are better off revving the **t out of it before changing to second. If memory serves me right though the stock CDI pours on the advance well before 13K so I think "spec" in this case is actually a mod moto?
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Mike Goebel
Joined: 28 Jul 2001
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| Posted: Sat Oct 20, 2012 5:41 am Post subject: |
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It's been a long time since I did it and from memory the curve I had hit about a max of 36HP and at 12600RPM the motor pretty much died do to ignition retard, I believe???
Mike G.
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Jason Berry
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Mike Goebel
Joined: 28 Jul 2001
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| Posted: Sat Oct 20, 2012 5:21 pm Post subject: |
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Why no HONDA??
Mike G.
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Steve Buckner
Joined: 22 Apr 2003
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| Posted: Sat Oct 20, 2012 6:13 pm Post subject: |
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Thats a spec class, there all the same.  |
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Jim McMahon
Joined: 07 Apr 2007
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Location: United States, St. Paul,
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| Posted: Sun Oct 21, 2012 8:32 pm Post subject: Re: ICC Dyno Curves |
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| Jason Berry wrote: | | Give me some time, I will post TM , Maxter, and Pavesi for you |
That'd be great Jason, thanks. Something to do over the winter...
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al nunley
Joined: 13 Nov 2006
Posts: 3027
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| Posted: Mon Oct 22, 2012 5:44 am Post subject: |
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Seems to me that you would want to shift at an RPM that lets the RPM drop to peak torque in the next gear. Peak torque at the axle means peak HP at the axle.
From the chart, peak torque is right at, or near, 10,500, so when you shift to 2nd, and so on, the RPM should drop to that RPM, if possible.
You know that HP is a calculation, right?
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Jim McMahon
Joined: 07 Apr 2007
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| Posted: Mon Oct 22, 2012 6:48 am Post subject: |
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It depends on the gear ratios and the powerband of the motor. Depending on the curve and the next gear ratio it can actually be beneficial to engage the next gear below or above peak torque. The gear ratios are generally fixed so you cant mess with those.. You can change the "final" gearing but that doesn't change the shift points, just the multiplication factor of the actual torque figure.
Torque at the axle is a direct function of the motor's torque taking into account the selected gear. The point of the exercise is to calculate what RPM shift points are optimal after calculating peak torque at the axle, or to be precise, the output shaft on the transmission.
You need to take the curve and ratios into account, not just the RPM where peak torque occurs.
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Jason Berry
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Jason Berry
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Jason Berry
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Jason Berry
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Jim McMahon
Joined: 07 Apr 2007
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Location: United States, St. Paul,
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| Posted: Mon Oct 22, 2012 11:37 am Post subject: |
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Thanks Jason. Interesting stuff. Are the marks on each graph intended as "don't drop below" and "don't go above" guidelines?
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