PDK Normal vs Sport
07-23-2014 | 01:05 AM
#16
Thread Starter
Racer
Joined: Dec 2013
Posts: 251
Likes: 1
From: Willoughby
OP I played around with it this morning quite a bit to see exactly what you were on about and it's very clear to me now that the up shift delay only ever occurs when commands are being given to upshift under a light load type throttle and/or an already low rpm environment in relation to the gear already selected.
Once the engine and PDK are already in or close to the optimum situation best suited to the gear selected the PDK starts to think twice whether it should obey the command to go into a taller gear again....possibly to stave off any event that taller gear lowers the engine RPMs beyond a critical point suitable for the load being placed upon the engine. I think if that particular program was not there then the driver could potentially up-shift the box beyond a critical point where the engine revs become simply too low for the load being subjected.
There is no doubt that once you apply a decent degree of load upon the engine and the revs are climbing at a rate that can support a taller gear the shifts become instantaneous both up and down. But if you are just fluffing around under light engine load and throttle trying to upshift the box for the sake of lowering revs further or saving fuel it thinks twice about obeying you. Not a bad thing.
Solution: Drive harder and faster!
Once the engine and PDK are already in or close to the optimum situation best suited to the gear selected the PDK starts to think twice whether it should obey the command to go into a taller gear again....possibly to stave off any event that taller gear lowers the engine RPMs beyond a critical point suitable for the load being placed upon the engine. I think if that particular program was not there then the driver could potentially up-shift the box beyond a critical point where the engine revs become simply too low for the load being subjected.
There is no doubt that once you apply a decent degree of load upon the engine and the revs are climbing at a rate that can support a taller gear the shifts become instantaneous both up and down. But if you are just fluffing around under light engine load and throttle trying to upshift the box for the sake of lowering revs further or saving fuel it thinks twice about obeying you. Not a bad thing.
Solution: Drive harder and faster!
I'm learning from y'all ...
07-23-2014 | 01:12 AM
#17
Rennlist Member
Joined: Sep 2013
Posts: 451
Likes: 54
From: Olympia, WA
One other random thought just occurred to me -- could this apparent hesitation now and then be down to the "virtual" gear effect where the PDK is actually putting some power through both clutches at once?? Perhaps that feels/sounds like a slower shift(?).
07-23-2014 | 02:14 AM
#18
Nordschleife Master
Joined: Apr 2010
Posts: 9,995
Likes: 393
From: Ny
Disclaimer : I haven't driven the 991 Turbo.
Although,I have driven the Carrera S with PDK. If left in Auto,the PDK will be in 6th or 7th gear(can't remember exactly) at 50 MPH!!! 50!!! I found this extremely annoying!
I do realize the Turbo's PDK software is set to shift faster and might behave differently,but even some 991GT3 owners with the super fast PDK-S are complaining that their car wants to be in the tallest gear ASAP when left in Auto in Normal mode.
My point is,how do you explain that the car wants to be in the tallest gear for fuel consumption purposes when left in Auto,but if you shift yourself too soon the computer interprets this action as potentially lugging the engine?
Although,I have driven the Carrera S with PDK. If left in Auto,the PDK will be in 6th or 7th gear(can't remember exactly) at 50 MPH!!! 50!!! I found this extremely annoying!
I do realize the Turbo's PDK software is set to shift faster and might behave differently,but even some 991GT3 owners with the super fast PDK-S are complaining that their car wants to be in the tallest gear ASAP when left in Auto in Normal mode.
My point is,how do you explain that the car wants to be in the tallest gear for fuel consumption purposes when left in Auto,but if you shift yourself too soon the computer interprets this action as potentially lugging the engine?
07-23-2014 | 02:24 AM
#19
Banned
Joined: Apr 2012
Posts: 2,422
Likes: 5
Disclaimer : I haven't driven the 991 Turbo.
My point is,how do you explain that the car wants to be in the tallest gear for fuel consumption purposes when left in Auto,but if you shift yourself too soon the computer interprets this action as potentially lugging the engine?
My point is,how do you explain that the car wants to be in the tallest gear for fuel consumption purposes when left in Auto,but if you shift yourself too soon the computer interprets this action as potentially lugging the engine?
2. Because the PDK's computer program is preordained to function within set parameters and a humans action can vary, resulting in error. Much the same reason why it won't allow a money shift. It would be like a manual being put into 7th when the engine is at 1200 in 6th. You would potentially have a situation of chugging. With the PDK they have evidently incorporated a safety factor to where chugging is never reached (at the hands of a human). On the other hand I have noticed if I drive the car off on a flat surface after a cold start and the cold start has deactivated, and im in normal, the box basically goes straight into second causing the engine to chatter/chug. Now that is stupid. Because when the engine is cold you want the revs above 1000 especially if you are in drive.