Thread: Shift times / shift speed for transmissions including automatic, DSG, DCT, SMG, SMGII, dual clutch, manual, etc.
04-19-2012, 09:48 PM #1
Shift times / shift speed for transmissions including automatic, DSG, DCT, SMG, SMGII, dual clutch, manual, etc.
This is an old post of mine but still relevant and thought you guys might be interested:
Now, here is actual documentation to support shift speeds and the reason why a dual clutch transmission simply can not be approached by an automatic or manual.
A dual clutch transmission is essentially two manual transmissions in one housing. One gear set is responsible for odd gears and one gear set is responsible for even gears. The next gear is essentially already preselected. When one gear set is disengaged, the other is already in gear and it is basically an instantaneous shift with no perceivable interruption. It happens forty times faster than the blink of an eye.
The VW group has their DSG numbers published and they are 8 milliseconds. Basically, a human being can not even perceive the gear change.
The fastest automatic in the world is the Lexus IS-F gearbox, at 100 ms. The ZF transmission in BMW's is at the 200 ms mark.
Unfortunately, a person with extreme bias posted numbers without realizing what they were posting or willing to admit reality, skewing numbers to misrepresent the facts due to personal issues.
Well, here are the numbers with support.
A long shift time is considered anything over 625 ms
The average manual car driver: 500 ms - 1 s
Aston Martin Vanquish: 250 ms
Ferrari 575M: 220 ms
BMW M3 E36 with SMG I: 220 ms
Ferrari 360: 150 ms
Enzo Ferrari: 150 ms
Lexus LFA: 150 ms
Ferrari FXX: Under 100 ms
Nissan GT-R: 100ms
BMW M3 E46 with SMG II: 80 ms
Ferrari 430 Scuderia & FXX Evoluzione: 60 ms
Volkswagen Golf GTI (Direct Shift): 8 ms
Bugatti Veyron (Direct Shift): 8 ms
All Volkswagen DSG Gearbox (Direct Shift): 8 ms
The source for shift times as well as DSG information is here if one is interested: http://paultan.org/2006/06/26/vw-pha...s-way-for-dsg/
BMW has not posted official shift times for the DCT unfortunately. Why not? Getrag just hasn't released the info officially but 4 ms has been posted as a "leak" on BMW sites.
The Nissan GTR time is stated odd and I believe it is simply due to how Nissan explains it cutting the shift time in R mode vs. regular mode. The GR6 Borg Warner tranny is not shifting slower than sequential manuals, just does not make sense. Maybe it is 100 ms though, but that would just be odd.
Just how big of a difference does the DCT make? Even vs. the best auto transmission in the world for shift speed, it will be picking up a conservative tenth per shift. What about vs. a manual? Well, here is a professional driver in a manual car vs. the same car in DSG, see for yourself:
So, hopefully this explains some things for people. All transmissions have their strengths and weaknesses, however, for flat out the fastest shift speeds available today, dual clutch transmissions do not have an equal and are simply on their own level.
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