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      09-19-2010, 02:26 PM   #10
Second Lieutenant

Drives: Spacegrau 2009 335i 6MT
Join Date: Feb 2010
Location: Houston, TX

iTrader: (0)

Originally Posted by GAaaAR View Post
Might be a stupid question, but can you explain why its optimal to shift once the previous gear's graph line drops below the next gears peak? I always thought its about the area under the curve? Even though it passed the optimal peak, its still producing more torque than other areas on the curve?
When people talk about area under the torque curve it's usually comparing a very peaky torque/power curve to a flatter one. One engine might make more peak torque, but the AVERAGE torque over a run (0-60, 1/4 mile, etc.) may very well be lower than an engine with a lower peak but flatter curve.

As for shift points, it's all about shifting when the wheel torque in the next gear will be more than your current gear. This is why Mr. 5 used the peak torque in the next gear.

In the higher gears, say 5-6 shift, if you wait until after 6000 rpm you will have less torque to the wheels in 5th than you would had you shifted to 6th for the same car speed.

The goal is to maximize the average wheel torque over the run...

2009 Spacegrau 335i