M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8230
  
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| Engine braking going downhill. |
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It has always facinated me how the gearbox on a auto "knows" the vehicle is going down a steep gradient and to use the engine for braking and will not change up unless the accelerator is pressed, where does it get this information from. It can when others can't,
It will when others won't,
It goes where others don't.
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 25th Jun 2023 6:36 pm |
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Disco_Mikey
Member Since: 29 May 2007
Location: Dundee, Scotland
Posts: 20842
  
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Throttle input, wheel speed sensors, engine requested/actual torque, current gear, Sport mode
All the above (and more) are used by the various modules to determine whether the box should change gear or not. Very clever cars  My D3 Build Thread
TDV8 Retrofit Build Thread
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| 25th Jun 2023 6:40 pm |
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M3DPO
Member Since: 22 Sep 2010
Location: Notts.
Posts: 8230
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Thanks for the reply  it has puzzled me for years, one particular road I use 4/5 times a year going into Bakewell, Derbyshire starts with an acute full lock "S" bend, probably 1 in 5, 5mph max to get round followed by 3/4 mile steep decline, the auto stays in at a guess 2 gear upto 3000rpm all the way down even when I lightly brake to keep the revs down, as you say very clever stuff. It can when others can't,
It will when others won't,
It goes where others don't.
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| 25th Jun 2023 7:24 pm |
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