Thread: DCT tranny
View Single Post
      12-02-2012, 06:36 PM   #34
gthal
Brigadier General
 
gthal's Avatar
 
Drives: 2015 M4
Join Date: Jul 2007
Location: Canada

Posts: 3,213
iTrader: (2)

Garage List
2011 M3  [3.37]
Quote:
Originally Posted by RPM90 View Post
Yes, in manual mode the ZF AT can down shift from 6th to 3rd nearly instantly, just as fast as a dual clutch.
And, it can do it by skipping gears too.
A dual clutch can skip gears as well, but since the gears are on 2 shafts, then how fast it can go from an even number gear to a lower even number gear may require a couple of shifts, and/or take less than a split second quicker.
Can the ZF down shift faster than a dual clutch?
Maybe in some cases, but how much difference does it make is a good question.

I like dual clutch trans, and after having my ZF 335i for a while I'll bet I may like it better as there are still some times when I can feel the torque converter doing it's thing in this trans.
Shift speed is amazing for a torque converter AT, and rivals DCT's.

But, there is a difference in feel. A dual clutch feels more like an MT because it is basically an MT that is automated, but the engine is connected to the trans by a solid clutch/clutches.
The ZF AT, as you know, uses a torque converter so you still feel that especially when driving hard.
In day to day driving though, the ZF AT feels smoother because of the torque converter and how it can dampen the power transfer from engine to trans.
If BMW had offered a DCT and ZF sport AT, I would likely have gone with the DCT for the reasons I mentioned.

BTW, have you driven an F30 with the sport AT?
If not give it a try. It's VERY impressive for a torque converter trans.
Great summary!

Only been in the new 3 series once so limited experience. My C63 has the MCT auto tranny and I bet it is very, very similar in feel and performance to the ZF. The shifts are similar in speed to the DCT but it is an auto (wet clutch instead of a torque converter). It is also a great transmission and FAST. From everything I have read, the ZF 8AT is great and would be a great choice if someone decided not to go 6MT. The hard decision will be 6MT or 8AT... the fact that the 8AT is so capable makes the decision that much more difficult.
__________________
2015 Austin Yellow M4 | Black Full Merino Leather | DCT
2014 Corvette Stingray | Z51 | Torch Red | 7MT - Sold
2012 C63 Coupe | Performance package | Obsidian Black - Sold
2011 E92 M3 | Jerez Black | Fox Red | DCT | Competition Package - Sold

Last edited by gthal; 12-02-2012 at 06:43 PM.
gthal is offline   Canada
0
Reply With Quote