Shift RPM Above Peak Power for MN6...
02-01-2007, 07:08 PM
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Shift RPM Above Peak Power for MN6...
Guys,
Just curious at what RPM above peak HP you are shifting your MN6 transmissions while drag racing? I have read that an old drag racer's rule of thumb states that the best shift RPM for a manual tranny is about 10% above peak HP. For example, if your motor reaches peak HP at 6000 RPM you would want to shift at about 6600 RPM to keep the engine in the "fat" part of the torque curve after the shift. Does this jive with what you guys are doing at the track?
Thanks in advance for your input!
Just curious at what RPM above peak HP you are shifting your MN6 transmissions while drag racing? I have read that an old drag racer's rule of thumb states that the best shift RPM for a manual tranny is about 10% above peak HP. For example, if your motor reaches peak HP at 6000 RPM you would want to shift at about 6600 RPM to keep the engine in the "fat" part of the torque curve after the shift. Does this jive with what you guys are doing at the track?
Thanks in advance for your input!
02-01-2007, 09:12 PM
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The idea is to shift so that you maximize the area under the HP curve for your motor.
If you have a dyno pull and know the tranny gear ratios you can calculate the shift point for each gear change.
If you have a dyno pull and know the tranny gear ratios you can calculate the shift point for each gear change.
02-02-2007, 06:43 PM
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The optimum shift point is where the horsepower has dropped off to the same level it will be at after completing the shift. That puts the peak power in the middle of the RPM range and makes for the greatest average power under the curve.