W. MITTY

This post is NOT intended to open a debate regarding PDK vs. Manual. Please don't interpret it that way, or I'm afraid I won't get the answers I am looking for.

I recently shopped for and purchased a 2013 991 C4S. While I have owned numerous 911 variants, all have been manual transmissions. In an effort to keep an open mind about all things automotive, I decided to explore the possibility of going with PDK this time.

I should mention that I presently own two other cars that have what I call "automated manual" transmissions, an SLS AMG and a 2013 Ferrari 458. I should also state that I am NOT a fan of automated manuals. Having said that, I have come to gauge these types of transmissions on shift speed. By that, I mean the delay between the time the lever is manually actuated and the ensuing gear change. For example, the SLS is quite pitiful in this regard; I pull the lever and it takes a good half second before the transmission responds. Ironically, when the SLS is in full auto mode, the time between gear changes as executed by the computer are quicker than I can blink. Thus, I drive the SLS in auto mode, just as I would a 1997 Buick. The SLS is a great car, but not when driven in manual.

The Ferrari, on the other hand, is quite impressive in manual mode. In most cases, it shifts the instant that the lever is pulled, either on the upshift or the downshift. It will probably come as no surprise that I virtually never drive the 458 in auto mode, simply because its such a pleasure to crack off those lightning fast gear changes. Makes me feel like I'm driving a Formula 1 car.

So, after reading everything I could, I tried the PDK. I drove it in both the Cayman and the 991, on two different occasions. I made sure I was in SPORT or SPORT+ mode. I wanted to like it. Unfortunately, I found a significant delay between manual input and gear change, most pronounced on the upshift. When I asked the salesman about it, he said "let me demonstrate" and proceeded to put the car in auto mode and mashed the throttle. Sure enough, it kicked down a couple of gears and the time between gear changes was blink quick. I agreed that the car shifted quite well on its own, but that I did not like the delay when it was in manual mode. He looked at me like I had something crawling out of my ears, as if to say "If you don't like the way it drives in manual, then drive it in auto" I finally gave up.

The good news is that after I found a manual transmission C4S and test drove it, I fell in love all over again and bought it.

So, the question: for those of you who have driven other automated manuals (especially the 458) how do you compare them with the PDK? Was I imagining the delay I noticed in the PDKs that I tested? Was I doing something wrong, or have I been spoiled by the 458? The reason I ask is because both the GT3 and the 991 turbo will exclusively feature PDK, and I am interested in both cars.

Your observations would be appreciated.

chuckbdc

My 991S PDK has no appreciable delay in manual shifting in Sport or Sport+. Once it is warmed up (eg 5 min) it pops off up or downshifts instantaneously. I have been told by friends who own both that the 458 shifts faster than the 991S PDK.

Then again, according to Porsche engineers in the release videos, the revised PDK in the GT3 has been made to shift even faster than the 458, and is the fastest shifting automated trans there is. The tech keeps moving forward.

onapex

curious, were you using the standard PDK buttons or the optional sports wheel paddles? from what I've read, the Ferrari is around 50ms and the upcoming GT3 is 100ms. the standard 991 is probably well above 100ms, so not surprised you can notice the lag. think around 300ms we're perceptive enough to notice the diff.

Rainier_991

I have a C2S PDK and I never drive in manual in either normal or sport mode as I hate the delay between pulling the paddle and something happening in the PDK. It's not a huge delay but when I pull the panel I want it "NOW".
In Sport+ however it speeds up noticably and is almost instant (close enough anyway). Due to this, for me: "manual mode = sport +".

Rainier

bccars

I didn't notice an irritating lag on my testdrives. But I'm comparing to Jag and Merc paddle shifters.
So I presume you are just used to your Ferrari lag and the Porsche has noticably longer lag for you !

trysixty

driving w the paddles seems like driving a F1 car to me in sport/sport+ mode, of course my paddle shift delay reference point was #1 wife subaru outback SUV I like PDK better than any 6/7MT I've had, but realize it probably is an "age" thing.

chuckbdc

Could it be that actual shift speed is also a function of throttle position? That is if your foot (or some other indicator) suggests you are not in a hurry, the transmission is mapped for more smooth rather than more fast?

WCE

The extremely quick shift speed of the dual clutch transmission comes from its preselection feature where the next gear is already engaged but the clutch is slipping. This seems to happen most reliably on upshifts while accelerating and after the gearbox is warmed up of course.
The Porsche PDK is the best automated manual I've driven, but if I had an SLS or a 458 in my garage it might stay parked most of the time regardless of the transmission!

stealthboy

I think we can agree the PDK shifts are fast, but I think the original question was about the delay between pulling the shift lever and the shift actually happening. I have a manual 991 so cannot comment, but I know on my Mini Cooper S with automatic paddle shifting the delay between pulling the lever and the shift actually occurring is annoying in how long the delay is.

Eric - Plug Guy

Don't own a PDK (6sp 09 Turbo), but did drive PDK cars at the Porsche Driving experience here at Lowes Motor Speedway a few months back. We were in 911's and Panameras, and it was a 'fun' experience to have them at speed and during quick acceleration to experience the PDK. It was nice.

However, the last F-car I drove was a 430 Spider F1, then a 6sp variant of the same model/year, so that's my only comparison. I would suspect the 458's F1 is better than the 430 was, but for me, the 430 driving experience with F1 was phenomenal. I also suspect Ferrari's long history with Formula 1 racing, vs Porsche's lesser experience in this form of racing lends itself to assume Ferrari can and will design a far better F1 product than Porsche will with PDK.

That said, I'm a stick guy, and the 430 6sp was the winner. I did not buy either, but it was fun.

Not trying to open the debate, but I would think Porsche has worked hard to get the PDK better (not yet 'right' but better) while Ferrari is still a step or two ahead in that game.

Congrats on the new Porsche though.

kosmo

Im lucky to have some nice friends and have spent some good seat time in the 458. The short answer is , yes its faster than the PDK in every setting. Even when comparing the 458 in Corsa vs the 911's Sport + mode, the former is faster. Personally (Im speculating here) I think software is part of the difference. So the 458 was the benchmark for the upcoming GT3. Lets see.

chuckbdc

Unless the Mini has a dual clutch transmission and mechanical mechanism to engage the clutches (eg no stator), the comparison is moot.

chuckbdc

RE experience with automated mechanical transmissions- Porsche developed and dominated with its PDK 20 years ago. The trans in Formula 1 cars is a quite different beast from what is in the street cars "F1" marketing designation and all.

stealthboy

Agreed, but I was talking more about the simple annoyance of any delay. I can understand the frustration.

kosmo

BTW, the 430 uses a true F1 tranny i.e. single clutch. The 458 is a Dual set up.
Frankly the 430, esp in Scud form, is AMAZING. the shifts are lighting and firm. Its not that great in auto mode in slow speeds and there's been some questions about the single clutch durability/life.

Lastly PDK box has been in development longer than F's Duo.