4.6L (1996-2004 Modular) Mustang Technical discussions on 1996-2004 4.6 Liter Modular Motors (2V and 4V) within.

optimal shift points

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Old Mar 2, 2011 | 07:43 AM
  #11  
TRUEBLUE3934's Avatar
TRUEBLUE3934
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One item I don't see mentioned here but that is important is the torque multiplication of the gear ratio in the trans. A dyno pull is just a graph of torque in the 1:1 trans ratio. Running the car a little longer in a gear is utilizing the torque multiplication of that gear prior to changing to a taller gear which multiplies the engine torque less. I'm guessing that running a little above the "optimum" power/torque shown on the dyno graph is more effective due to the additional torque output from the gearing.

Somebody tell me if I am missing something.
Old Mar 2, 2011 | 07:48 AM
  #12  
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cliffyk
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The entire exercise was built around the "torque multiplication" of the tranny and rear-end--I do not understand your concern?
Old Mar 2, 2011 | 07:58 AM
  #13  
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Correct me if I'm wrong, but I was always told that if you feel the hang and the sudden jolt when up shifting then you've shifted too late, as the car is actually slowing down and then speeding up again. The biggest problem with consistency with a manual is the fact that we don't have a proper way to ensure acceleration during shifts like an automatic would, so you can't always shift at peak numbers, but sometime right before/after to allow the next gear to engage at a more even power preventing the car from slowing down between shifts. Idk, just what I've heard. I do admire the visual representation via matlab, one of the best uses I've seen other than matrices/iterations for calculus. lol
Old Mar 2, 2011 | 05:28 PM
  #14  
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TRUEBLUE3934
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Originally Posted by cliffyk
The entire exercise was built around the "torque multiplication" of the tranny and rear-end--I do not understand your concern?
OK. I guess THAT is what I had missed. I thought it was just a look at the graph from a dyno pull with rpm ranges in each gear represented as the car goes through the gears. After looking again, I can see adjustment for taller ratios as it progresses up in trans gears. That is what I was thinking was most critical.

I figured I must have been missing something, because I thought you guys were smart enough to take all of that into account.
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