06-09-2014, 10:56 AM
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#31
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Join Date: May 2013
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Quote:
Originally Posted by DarkSunrise
The way I had always calculated it is, you have to compare torque to the ground (i.e., multiplied through the gearing) in the two gears. So to determine the shift point for the 1-2 shift, you would compare torque to the ground in 1st gear at 7000 rpm vs. torque in 2nd gear at 4500 rpm. Then 7100 rpm vs. 4600 rpm. Etc.
When torque to the ground in 2nd gear exceeds the same in 1st, that is your optimal shift point. If 2nd never exceeds 1st, then you should shift at redline.
Because of the way gearing is setup in most cars, it ends up that the optimal shift point is at/near readline in the lower gears, but gets lower as you go up the gears.
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This should give you the exact same results as the power method I described - torque to the ground will be the same at a given speed if power is the same.
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