lnirenberg

Have about 2500 miles on car with main use to, on & from track. I am having an intermittent problem with the PDK. Approaching sharp corners in 3rd, brake then accelerating out the PDK seems to be confused as to whether it should be in 2nd or 3rd and as I add gas it almost feel like it’s in neutral until it finally makes up its mind. Coming from a 991 GT3 & TTS I’ve never had this happen before. In an hr of track time I’d guess it happens 3-4 times. Anyone else had this issue?

Xxyion

I don't have my GT4 yet so I can't say for sure till I myself get out on the track. But I am curious, it sounds like you keep your transmission in Automatic mode? I was under the impression Manual Shifting is the best. That being said, one of my friends did tell me that when he was in his GT3 on the track, the car could be kept in automatic because the PDK just knew what gear he needed to be in. So I wonder if maybe its a tuning issue?

enduro

Haven't had that issue so far, but I managed to confuse mine on my track, so I run it in manual mode.

Drivingoncords

I haven't had this exact issue, but on track my pdk gt4 will consistently not downshift into 2nd gear when going into corners where 2nd is the proper gear.

To solve this problem, I use the paddle to downshift into 2nd, while still in automatic mode. By the time I need to upshift to 3rd, the pdk has already reverted back into auto mode and does it for me.

KelvinC

With my 718 GT4, I run in PDK SPORT mode + full auto all the time, and have not noticed an issue like this. I mostly run at Laguna, which has a few mid-to low-speed corners where I enter in 3rd and accelerate out. I've found PDK to be brilliant, and I never feel the need to shift myself.

The only time when I feel like PDK takes just a split second longer...is when there's some awkwardness re: a train of point-bys, and passing one car at a time—accelerating and coasting, etc, isn't always the smoothest experience.

Reedy

Shift manually. Not only will it eliminate this problem but it will connect you with the car in a much more cohesive way, and you will almost certainly go faster.

RoadrunnerGTS

On track you really want PDK in manual mode, don't leave it up to the computer. Porsche, BMW, Merc all the same. Even on street manual shifting in these cars is more rewarding, not that I have a PDK car currently.

UncleDude

wait, wait, I thought the PDK was supposed to be “telepathic”….😂



I’m a fan of the PDK by the way.

Larry Cable

I was convinced by a friend to leave the 4RS in "auto" mode for approx 1 lap at the 'Ring when I attended the PSDS earlier this year, all it took were a couple of unexpected shifts mid corner
for me to abandon that idea and throw it into manual mode...

While PDK is an excellent transmission, you, the driver have more information available to you than PDK has, it does not know where you are on the track, (or that you are on a track for that matter)
nor does it know what's coming next or what you plan to do next either ... all it has is linear/lateral g, accelerator and brake inputs and engine rpm... and a algorithmic map to convert that info into shift decisions.

knock it into manual mode and shift with the paddles ... you will extract more from the car, the experience, and from yourself ... or get a manual and do it the old fashioned way.

YMMV

Larry Cable

it uses "the force" I believe ...

Porsche444

Paddle shift, it’s way better. Takes a bit to get used to it, but it’s way better.

Larry Cable

PDK-S programming may ( and most certainly does) differ even from GT4 programming is my guess - you might talk to Cobb about potential PDK/TCU tune - or bat it into manual and use the paddles.

as I mentioned above, my 2 days in the GT4RS at the 'Ring, the car shifted a couple of times in mid-corner which I did not appreciate, so I knocked it into manual voila only myself to blame for mis-shifts!

Note the car has a decision to make, the PDK is "dual" clutch (hence the Doppelkupplungsgetriebe) so when it is in one gear - it has to decide what 'other' gear to pre-engage one-up or one-down (on the other clutch) from the currently engaged gear.

sometimes it makes the wrong guess... or waits a while to decide which one to bet on...

until such time as someone attaches GPS and a 3d map with the ECU & TCU probably along with some autonomous driving technology such as LIDAR - your own "organic" TCU has better information about the near future needs than the current tech has IMO YMMV

Reedy

The GT2 RS that I pit crew for a friend at Tarmac Rallies competes in events that have 200kph speed limits. The car can hit 200kph in 4th gear.
We have a crude ECU map that shuts off the throttle at that speed and then starts coasting. In auto mode the gearbox will upshift from 4th to 7th, then as soon as speed drops below 200 it immediately goes full throttle again, downshifts back to 4th and back up again when the speed limit is reached. It's an extreme example, but its just the gearbox making its best guess. This issue forced him to shift manually all the time, I understand the desire to outsource as much of the mental load as you can while driving, but short of the self driving LIDAR technology mentioned above, you're not going to get a perfect system that is always in the right gear all the time.

TRZ06

Completely agree with this.

I have even confused the PDK in aggressive street driving. Also, even in Sport+ it will still shift too early often. If you have the throttle pinned, it will give you redline shifts, but all it takes is to ease off for just a quick bit and it wants to act more civil right away.

For max performance driving I always use manual now. Normal mode is good for highway driving or when with the Significant Other and Sport+ is good for spirted driving.

Larry Cable

I also suspect that PDK-S is simply a more aggressive 'shift' map and a transmission oil cooler, but that's simply a guess ...

the honest truth is, I am a luddite/dinosaur, all my cars (with the exception of the 991.1 GTS cab I had - which I Cobb TCU tuned because I disliked the PDK shift algorithms so much) are (and will be for as long as its possible) 6MT cars ... brrrm brrrm ... its what I know and what I enjoy