Quote:
Gnil said:
Does any one know the difference with PDK when in ' track mode ' ?
What does it change exactly ?
Quote:
Grant said:
Very interesting! How does this "Brief Overboost of Power" occur with a non-turbo motor? Does it just allow further revving past 7,500 rpm? If so, this is not much of a benefit (since max power is achieved at 6,500 rpm) and would be totally unnecessary if the gears had been made closer together to take advantage of the 7 gears in PDK, instead of just tacking on an economy 7th gear ratio...
Quote:
KresoF1 said:
IMO it means that electronic is simply adding throttle bip of some kind during upshift as well. You CAN NOT rev it more then 7500rpm, even in Sport Plus mode...
Quote:
KresoF1 said:
BUT, I can bet with you that shifts are not smooth at all in Sport Plus mode.
Quote:
Grant said:Quote:
KresoF1 said:
BUT, I can bet with you that shifts are not smooth at all in Sport Plus mode.
I hope Porsche does not make the shifting jerky just to make it "feel" faster like BMW did with their DCT, unless it actually improves performance. Otherwise, this is a performance negative and causes more wear on the drive components, imho...
Quote:
KresoF1 said:
BTW, what do you think what version is faster around Ring-manual or PDK? In good driver hands...
Quote:
Grant said:Quote:
KresoF1 said:
BTW, what do you think what version is faster around Ring-manual or PDK? In good driver hands...
I think the PDK will be a little faster, due to some of the gear ratios (like 2nd and 3rd) being closer together and the lack of thrust interruption while upshifting...
Quote:
gw2009 said:
There has been some speculation that the only reason the GTR came close or beat 911 Turbo around Ring, and other tracks (see CAR, EVO etc.) has been the time saved on faster shift times. I.e. imagine how many times you shift around the West Circuit, let alone the Ring, then calculate the quicker shift times versus a manaual (think GTR is 100 ms vs. ...), and you suddenly have a large deficit to make up in your turbo.
Quote:
gw2009 said:
There has been some speculation that the only reason the GTR came close or beat 911 Turbo around Ring, and other tracks (see CAR, EVO etc.) has been the time saved on faster shift times.
Jun 10, 2008 9:01:59 PM
Jun 10, 2008 9:19:24 PM
Jun 11, 2008 1:23:12 AM
Quote:
intouch1 said:Quote:
davew (cincy) said:
Grant,
If I understand the double clutch correctly, the added weight is not just added, some of it is also rotating.
A question I have related to the double clutch, is how quickly you can downshift two gears...?
even gears are on 1 shaft uneven on another. you could shift directly from 7th to 3rd....
the rotating assembly is not heavier. the whole transmission is heavier due to the double set of gears involved. still, pdk is lighter than tiptronic.
Jun 14, 2008 9:00:44 PM
Quote:
davew (cincy) said:Quote:
intouch1 said:Quote:
davew (cincy) said:
Grant,
If I understand the double clutch correctly, the added weight is not just added, some of it is also rotating.
A question I have related to the double clutch, is how quickly you can downshift two gears...?
even gears are on 1 shaft uneven on another. you could shift directly from 7th to 3rd....
the rotating assembly is not heavier. the whole transmission is heavier due to the double set of gears involved. still, pdk is lighter than tiptronic.
I don't think you are right here - please correct me if I am wrong, but the double clutch has two clutches (more rotating mass) and two shafts (again, more rotates). Also, it is the two shafts that allow pre-selection of odd gears while driving in even, and vice-versa. This is where the shifting speed comes from. I expect an immediate downshift of two gears would require a (slightly) longer delay...? Anyone else??
Also, with two clutches (concentric?) one is much larger (diameter) than would normally be necessary...?
Jun 14, 2008 11:25:20 PM
Jun 15, 2008 6:42:31 AM
Jun 15, 2008 2:43:29 PM
Quote:
davew (cincy) said:
Thank you sir.
One further question, if I may.
I understand the concept of "preselection" but how does this happen during down-shift as well as up-shift...?
How does the controller (computer, whatever) know if I intend to move from third to fourth, or back down to second? Is it only truely accomplished while heading up through the gearing? Or does it assume shifting continuity (if I went down last time, assume down will happen again - accept, perhaps for first and seventh...)
OK, thinking too much here - but still would like to understand...
Or perhaps Porshe prefers to keep this level of detail under wraps.
Jun 19, 2008 4:04:06 AM
Jun 19, 2008 5:54:45 AM
Quote:
RC said:
This was the only way to achieve EURO 5/etc. certification I'm afraid.
Sportscar manufacturers and especially SUV manufacturers will find it more and more difficult to certify their engines/cars in the future due to more restrictive environmental laws.
Jun 21, 2008 10:22:44 AM