11-29-2014, 10:07 PM | #1 |
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Dct downshift...
So before I got my M4 back in June, I was driving a 2011 335is, it was a awesome car and I never had any problems or complaints about it. One thing I totally loved about the car was it's downshift from 5th, 4th, 3rd, and 2nd gear; it was a Dct, and it was always in sport mode.
The way it downshifted is a lot different than my F82, whenever I braked in my old car the engine would rev and you would feel resistances or drag as it declined in speed and gears. Now my current car "F82" it's always in M1 with all settings in sport plus. The difference between these two cars can be felt when I brake, so the engine revs sometimes about 70% depending on how I brake; but in 3rd and 2nd gear on deceleration the F82 has zero drag or resistances. Making for some of the most jerky braking around, and it's like the car just wants to keep going. I don't know if anyone else can relate to what I'm talking about, but I am wondering if there is a way to get that "downshift resistance" feeling in the F82. Last edited by ///M Villain; 11-29-2014 at 10:44 PM.. |
11-30-2014, 02:50 AM | #2 |
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What you're referring to is "Compression Braking".
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11-30-2014, 07:17 AM | #3 |
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I feel exactly what you want in my M4, but not in my n55 335i. But it is relatively smooth at downshift when I drive my friends F80 M3. I'm also looking forward someone can help to explain.
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11-30-2014, 07:39 AM | #4 |
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I'm not sure I understand completely.
The M does engine brake on downshifts... it has to and all cars would. My guess is the car is rev matching and smoothly downshifting in a way that you don't feel the engine compression as much... but it is absolutely there. If you downshift without braking, you can absolutely feel the compression resistance you are talking about. I find braking and downshifting in the M4 to be SUPER smooth so when you say downshifting and braking are jerky I don't know that I have experienced that. Maybe I'm misinterpreting your post?
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11-30-2014, 01:14 PM | #7 |
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What do you mean by M1 ?
What DCT setting do you use ? |
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11-30-2014, 01:25 PM | #8 |
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You may be noticing a lack of engine braking due to being in sport+.
In sport/sport+ the turbo anti lag is active. From what I have read this work by having some of the cylinders still firing to generate enough exhaust to keep the turbo's speed up, this would be more than enough to overcome the engine compression braking. |
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11-30-2014, 03:01 PM | #9 | |
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11-30-2014, 05:10 PM | #10 |
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11-30-2014, 05:22 PM | #11 | |
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11-30-2014, 11:06 PM | #12 |
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11-30-2014, 11:08 PM | #13 | |
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However, that still doesn't answer what DCT Drivelogic mode you use ? |
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11-30-2014, 11:28 PM | #14 |
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12-01-2014, 01:09 AM | #15 |
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