Anyone Regret Buying a PDK?
03-22-2009, 12:20 AM
#91
Race Director
There is no delay when shifting a PDK, put it in manual mode and sport mode and it will bang them off as...turn on the PLUS Chrono mode and it will change gears faster than a Ferrari.
I drove a Maserati a few yrs ago which had the Ferrari paddle shifter. Was very intuitive and not complicated to drive.
I drove the PDK today for the first time. In auto it was smooth and surprisingly good.
In manual I had to think every time "push or pull" whether I was usingthe stick or the rather silly buttons.
Personally I would prefer paddles. But I could live with the buttons ifit was pull for "up" and push for "down" just like one would expect in a sequential shifter. At least to me, on the track as you are braking hard with the momentum going forwards, if you have to be pulling or pushing things, its better to "push" and vice versa.
In manual mode it seemed to have a delay in shifting gears and was odd. Almost as if I had to predict where it would actually shift. Maybe this is lack of familiarity, or maybe I needed sport plus on, I dont know. OTOH inmanual, if I lifted as I changed gears if felt more normal.
I drove the PDK today for the first time. In auto it was smooth and surprisingly good.
In manual I had to think every time "push or pull" whether I was usingthe stick or the rather silly buttons.
Personally I would prefer paddles. But I could live with the buttons ifit was pull for "up" and push for "down" just like one would expect in a sequential shifter. At least to me, on the track as you are braking hard with the momentum going forwards, if you have to be pulling or pushing things, its better to "push" and vice versa.
In manual mode it seemed to have a delay in shifting gears and was odd. Almost as if I had to predict where it would actually shift. Maybe this is lack of familiarity, or maybe I needed sport plus on, I dont know. OTOH inmanual, if I lifted as I changed gears if felt more normal.
03-22-2009, 01:43 AM
#92
03-22-2009, 01:48 AM
#93
Nordschleife Master
For the car yes there is a force opposite its velocity vector, but for the driver his momentum is forward... the driver is an isolated body without brakes, except his seatbelt...
Last edited by ADias; 03-22-2009 at 04:07 AM.
03-22-2009, 04:32 AM
#95
The momemtum of the driver is in a net negative direction too as his forward speed before being restrained is tiny compared to the cars deceleration.
03-22-2009, 05:09 AM
#96
Nordschleife Master
03-22-2009, 04:51 PM
#97
Of course we're talking about the change in momentum as the your forward momemtum is always positive unless you are in reverse gear.
My point is that within a fraction of a second you are restrained by the seatbelt and the change in momentum for both the vechicle and the occupant is rearwards.
My point is that within a fraction of a second you are restrained by the seatbelt and the change in momentum for both the vechicle and the occupant is rearwards.
03-22-2009, 07:59 PM
#98
Track Day
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Eh? Right car..?
"While the manual is absolutely great in light to no traffic, especially on a winding road, I was hardly ever getting a chance to do that with my 07, and trust me, it is no fun driving a manual in Houston traffic.
With my new 09, the PDK not only takes away the tediousness of continually manually shifting in stop-and-go traffic, but it is fantastic for allowing me to quickly maneuver when an opening presents itself.
It would still be nice to have a manual transmission-equipped car to play with, but I am getting far more use from the 09 C2S PDK than I ever did with the 07 C2S and really now almost look forward to my daily 22 mile one-way commute."
This really puzzled me. If you rarely encounter light traffic or winding roads it seems your Porsche problem is not the transmission, it's where you live and how you use the car. I'm not sure I would be choosing a 911 primarily for commuting in heavy traffic...
With my new 09, the PDK not only takes away the tediousness of continually manually shifting in stop-and-go traffic, but it is fantastic for allowing me to quickly maneuver when an opening presents itself.
It would still be nice to have a manual transmission-equipped car to play with, but I am getting far more use from the 09 C2S PDK than I ever did with the 07 C2S and really now almost look forward to my daily 22 mile one-way commute."
This really puzzled me. If you rarely encounter light traffic or winding roads it seems your Porsche problem is not the transmission, it's where you live and how you use the car. I'm not sure I would be choosing a 911 primarily for commuting in heavy traffic...
03-22-2009, 08:20 PM
#99
Rennlist Member
"While the manual is absolutely great in light to no traffic, especially on a winding road, I was hardly ever getting a chance to do that with my 07, and trust me, it is no fun driving a manual in Houston traffic.
With my new 09, the PDK not only takes away the tediousness of continually manually shifting in stop-and-go traffic, but it is fantastic for allowing me to quickly maneuver when an opening presents itself.
It would still be nice to have a manual transmission-equipped car to play with, but I am getting far more use from the 09 C2S PDK than I ever did with the 07 C2S and really now almost look forward to my daily 22 mile one-way commute."
This really puzzled me. If you rarely encounter light traffic or winding roads it seems your Porsche problem is not the transmission, it's where you live and how you use the car. I'm not sure I would be choosing a 911 primarily for commuting in heavy traffic...
With my new 09, the PDK not only takes away the tediousness of continually manually shifting in stop-and-go traffic, but it is fantastic for allowing me to quickly maneuver when an opening presents itself.
It would still be nice to have a manual transmission-equipped car to play with, but I am getting far more use from the 09 C2S PDK than I ever did with the 07 C2S and really now almost look forward to my daily 22 mile one-way commute."
This really puzzled me. If you rarely encounter light traffic or winding roads it seems your Porsche problem is not the transmission, it's where you live and how you use the car. I'm not sure I would be choosing a 911 primarily for commuting in heavy traffic...
As for my reasons for choosing a Porsche and choosing to sometimes drive it to work in Houston, I am near retirement (within two years, state of the economy notwithstanding), and we plan on moving to the Hill Country at that time. In the meantime, I am thoroughly enjoying my new car and plan to continue to do so, even if I sometimes have to drive it in traffic. Hope that is OK.
04-18-2009, 01:44 PM
#100
Instructor
Mini physics and math lesson...
Of course we're talking about the change in momentum as the your forward momemtum is always positive unless you are in reverse gear.
My point is that within a fraction of a second you are restrained by the seatbelt and the change in momentum for both the vechicle and the occupant is rearwards.
My point is that within a fraction of a second you are restrained by the seatbelt and the change in momentum for both the vechicle and the occupant is rearwards.
Momentum is proportional to the first derivative of position = Mass x Velocity
Force is proportional to the second deriviative of position = Mass x Acceleration
When you say "change in momentum", you are in fact talking about the first derivative of momentum, which is force.
So when you are slowing down, you are experiencing negative acceleration while you continue to move with forward momentum.
For even more geekery, I'll admit that when I was in college decades ago, I took an entire engineering class devoted to vehicle dynamics.
04-18-2009, 06:00 PM
#102
Sorry about the geekery...
Momentum is proportional to the first derivative of position = Mass x Velocity
Force is proportional to the second deriviative of position = Mass x Acceleration
When you say "change in momentum", you are in fact talking about the first derivative of momentum, which is force.
So when you are slowing down, you are experiencing negative acceleration while you continue to move with forward momentum.
For even more geekery, I'll admit that when I was in college decades ago, I took an entire engineering class devoted to vehicle dynamics.
Momentum is proportional to the first derivative of position = Mass x Velocity
Force is proportional to the second deriviative of position = Mass x Acceleration
When you say "change in momentum", you are in fact talking about the first derivative of momentum, which is force.
So when you are slowing down, you are experiencing negative acceleration while you continue to move with forward momentum.
For even more geekery, I'll admit that when I was in college decades ago, I took an entire engineering class devoted to vehicle dynamics.
I don't know why people are confused and think that the gear selector directions chosen by Porsche are wrong when , in fact, they simply don't understand the forces at play when changing speed. In fact the forward body motion when decelerating is not caused by any force in Newtonian mechanics. It is analogous to the Coriolis effect in rotating reference frames.
04-18-2009, 07:11 PM
#103
Rennlist Member
Having recently driven a PDK on a C2S at Barber (3-day PSDS course), I feel that the shift levers are actually quite well designed and very natural to use at speed. I am also a person who thought the design looked bad before actually using it IRL. It could also be that I have not driven any other +/- automatic style cars with the exception of our Cayenne which is needless to say not a track car.
The easiest way to use the PDK in a braking zone is to simply pull pull pull pull and let the car find the lowest usable gear. I did not bother manually upshifting.
I guess my feeling is that regardless of whether or not you are experiencing accelerative or decelerative forces, I don't think the orientation of the +/- is important....they seem to work well the way they are.
The easiest way to use the PDK in a braking zone is to simply pull pull pull pull and let the car find the lowest usable gear. I did not bother manually upshifting.
I guess my feeling is that regardless of whether or not you are experiencing accelerative or decelerative forces, I don't think the orientation of the +/- is important....they seem to work well the way they are.
04-18-2009, 07:18 PM
#104
Having recently driven a PDK on a C2S at Barber (3-day PSDS course), I feel that the shift levers are actually quite well designed and very natural to use at speed. I am also a person who thought the design looked bad before actually using it IRL. It could also be that I have not driven any other +/- automatic style cars with the exception of our Cayenne which is needless to say not a track car.
The easiest way to use the PDK in a braking zone is to simply pull pull pull pull and let the car find the lowest usable gear. I did not bother manually upshifting.
I guess my feeling is that regardless of whether or not you are experiencing accelerative or decelerative forces, I don't think the orientation of the +/- is important....they seem to work well the way they are.
The easiest way to use the PDK in a braking zone is to simply pull pull pull pull and let the car find the lowest usable gear. I did not bother manually upshifting.
I guess my feeling is that regardless of whether or not you are experiencing accelerative or decelerative forces, I don't think the orientation of the +/- is important....they seem to work well the way they are.
04-18-2009, 10:44 PM
#105
Race Director
I wish all of you could have taken a ride with me at Sebring today. PDK is AWESOME....lightning quick shifts, perfect rev matches...made shifts like Patrick Lomg!!!!. The toggle levers on the steering wheel worked great.
