Quote:
Originally Posted by swamp2
From the most recent issue.
1. According to Viper engineers a DCT would be good for at least a 3 second improvement in its Nurburgring time. I would bet that is actually found from testing not purely guess work. However, it does raise the very relevant question, what is the real source of the gain, faster shifts, more gears, better ratios or all three? Either way this probably makes for a reasonable estimate for what we should expect from the M-DCT (if we ever get any bloody Sportauto time for the car...). Link to a link of the article here.
2. A nice discussion of many points that have turned into fierce debates here in the forum on the topic of MT vs DCT. Note: If it is good enough to be the only transmission choice on the new Ferrari 458, it is probably good enough for any of us and the M3. Of course the article does discuss the role of personal preference as well. It does conclude firmly on the pro DCT side offering the obvious choice for a real "go fast" - use your newly freed up left foot for braking! Link. |
As I see it, the majority of that advantage comes from the following:
a) The precise lightening quick 10-30 millisecond 1st thru 7th gear shifts that only DCT can deliver on a consistent basis. (no human driver can match that)
b) The combination of the DCT's transmission gear ratio
combined with the differential gear ratio. (final drive)
c) The fact that the next gear change is always "pre-selected" by the DCT's control module based on the acceleration (and mode) your DCT tranny is in at the time. (the next gear is ready and waiting to be engaged on a separate clutch shaft)
d) Perfect rev-matching downshifts improves the efficiency of the gear changes and maximizes your performance. (lowering the overall lap time)
e) With DCT, there is no hydraulic 'fork' to engage or disengage in order to change gears. (upshifting or downshifting) This was the reason so many people disliked the clumsy way the SMG tranny functioned. (under heavy acceleration, the clutch engagement was very abrupt)
The DCT transmission in our cars allows all the engine power to be applied gradually (perfectly modulating the clutch engagement via electro-hydraulic closed loop system) when a vehicle is moving. This is all monitored and controlled by a computer algorithm that can repeat perfect shifts all day long. (no human driver can do that either) The DCT transmission will only briefly interrupt the flow of power for a few milliseconds to perform these gear changes. (well...since the latest DCT update! lol...) The DCT transmission engages the clutch in the most efficient manner possible, and this allows more of the engines power to transfer to drive wheels with minimal delay or loss.
Bottom Line: The DCT transmission can almost instantly engage and disengage the clutch to start/stop the transfer of power from the engine to the drive shaft. (which will beat the overall efficiency of a traditional 6-speed manual transmission and human driver engaging and disengaging a mechanical 3rd pedal clutch during a race)
What is your theory Swamp?
