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      03-26-2008, 01:02 PM   #43
swamp2
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Drives: E92 M3
Join Date: Sep 2006
Location: San Diego, CA USA

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First, a big thanks to Just Me for the breaking news on a very hot topic. Thanks as well for the initial translations and the much improved work by South!

I am very pleased and excited. If I could offer my interpretation of a part of the translation I would say folks agree that M-DCT is a very strong evolutionary step past SMG, maybe not revolutionary but that is fine becuase I think SMG is pretty darn good.

Quote:
Originally Posted by GT3 Tim View Post
Sheez, its like reading Yoda. lol. Thanks though, I got something out of it...I think.
You read my mind on that one, Yoda, ha.

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Quote:
Originally Posted by T Bone View Post
Looks like M-DCT isn't going to give an extra 20hp in performance and solve world hunger.

It is going to be an awesome, reliable, smooth gearbox, clearly better than SMG3.....

But Swamp2 is not going to like there is a perceptable interruption in acceleration. But he should be happy of the neck snapping effect of a S6 upshift.....

The M3 is going to chirp gears all the way from the 3rd gear to 4th gear upshift.
DCT WILL be worth about 20 hp and 20 ft lb (equivalently). The larger gear ratios AND shorter shift times will do this, period. If you do not disagree that the car will be measureably faster how can you disagree that there is not a significant and equivalent hp/tq gain? You've got this one wrong.

As far as the perception of gear changes it sounds like the system offers a full range of performance, barely noticeable changes in some modes, and noticeable not not nearly as noticeable as SMG in other modes. This does not mean much as all in terms of the performance advantages. All it really means is that I was a bit wrong about the particular design direction they took and whether or not super fast could be mixed with super smooth. That being said I always agreed with enigma that there is a certain amount of engine, flywheel and drivetrain inertia and that has to go somewhere.

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Quote:
Originally Posted by footie View Post
I am less impressed by this review, especially the jerk during upshifts. The whole reason of dual clutch is to be seamless in the changes, not noticeable and jerky like they were with SMG. Unless my understand of what the guy that wrote this is different I doubt I will like this that much.

I would also like to see performance figures for each of the different modes (Auto and Manual) to see if they effect the acceleration. If so then in my opinion BMW have f--ked things up BIG TIME.
Hello, Debbie Downer. Wake up footie. Everyone loved the tranny. You can't really honestly believe that "BMW have f--ked things up BIG TIME"... Or can you? Did you hear how the one magazine tester thought the GT-R DC system made the Scuderia feel slow and anitquated? That is UNREAL praise. M-DCT will be the same.

It is smoother than SMG as you get less jerk. You need to really think about the math and curves here before you drive and before you pontificate. SMG and MT exhibit a larger jerk or derivative of acceleration becuase they both decelerate and then accelerate during a very short interval. Hence the slam/jerk. With DCT you still get the excitement and perception of the speed through some jerk but less because the shift is so fast and the entire dip in velocity and acceleration is eliminated.

Consistent with the goal of having a very tuneable car it seems BMW wins here with the tranny by offering both very smooth modes and ones with a smaller but exciting jerk.
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