Recently picked up a 2013 C4S 7 speed manual with PDCC. I used to drive a 997S and 997TT before picking up this 991. I have some local twisty roads that I love and took the C4S through the corners and noticed somewhat of a delayed "shift" sideways by the rear of the car following steering input. I am able to reproduce it fairly consistently and it is a tad unsettling - makes me not want to take the corners too hard - particularly the switchbacks.


I've been researching if it's PDCC, newer tires, or maybe me just getting used to a rear engine car again. This morning, I had my friend who drives a 997S and without prompting him, he said he felt the same thing. Really made him worried about taking the corners hard. He also said the car felt much bigger and heavier. I presume that has some to do with AWD and some to do with electric steering.


Curious if anyone else has experienced this. I want to try a 991 C2S to see if it's just because it's a C4S, but I can't imagine the difference is THAT pronounced. I've got about 1k into the new rear pzeros, so maybe that will be addressed over time.


Otherwise, the car is great. Definitely feels more GT than the 997, but still great fun to drive.

 

I have a 4S with PDCC. I don't get any of that uneasy feeling and I drive twisty Penn back roads every day. I am running new Michelin Super Sports that are superior to the OE Pirellis (in my opinion).
Car is flat in the turns, I never feel uneasy on the road.

 

What tyre pressures are you running? I have a GTS with PDCC and it felt squirrelly as hell in corners until I reduced the rears to 'comfort' pressures. It completely sorted the problem and now the car handles perfectly. PDCC seems really pressure sensitive. Maybe give that a try.

 

Really good question. Don't over inflate. I am running cold tire pressure 32 front 36 rears and the car is planted. It's a proven 4 wheel drive platform it should be like glue in the twistys.

 

Wow, ok. They are currently 38/45. That could be the problem! Will try and report back.

 

Wow that's too high. Let us know how it drives after.

 

So, reduced the pressure and drove pretty hard through some local roads. Car improved, but still felt a little shift. May be in my head, but was really wanting it to be perfect.

 

How old are the tires and what pressures did you set at.?

 

Sounds like you got most of the way there moving to reasonable tire pressures. There may be more in fiddling with the pressure balance between the fronts and rears too. And since its got a few miles on it, it may be with getting the alignment checked- if thats out or spec that could affect handling and lower tire life too.

Every C4S I have driven has felt rock solid.

 

18000 miles on 2013 C4S with PDCC. Car is ridic on the turns. My cold pressures are comfort per the door PSI.

Car should be really confidence inspiring in turns especially with PDCC. Can you try another car to compare? Come drive mine.... might be a bit far from Seattle.

 

I agree with Chuck. What pressures are you running? tire wear, and alignment could be an issue. Car should be a cheetah in the corners. Don't be afraid to go to lower pressure.

 

I agree. Go comfort pressures, and if that doesn't work get the alignment checked. One more thought: the 'shift' you're feeling could be the torque vectoring (braking of the inside-rear wheel when a sharp steering input is detected). I sometimes sense that's giving the car a feeling on turn-in of pivoting about its hips when I go hard into a bend, but I really like it, and it's definitely nothing to worry about...

 

I'll just add my $0.02... I'm running with slightly higher than comfort psi all-around on the OEM Pirelli's. Seems the harder I've pushed the car into the corners the more solid it feels -- the only unsettling I've ever felt has been momentary slippage on road surface changes. Pushing the throttle further in those conditions usually works best....

 

This is probably not it, but I'll share my experience. When new, my car never felt settled in turns, it had a bit of what the OP describes and I had zero confidence in the handling of the car. I guessed that it was just "the way it is" and drove cautiously.

Later (a month?) the car started to develop a clunk. It was intermittent, and finally it got frequent enough that I could take it in for service. It took them 2 days to figure out that the left rear shock was broken. That was all I got for an explanation. "Broken". So once that was repaired, the car handled much better!

However, my car did not have PDCC and I ran it on "comfort" pressure always, with the rears around 32 PSI. The car does kind of settle-in on hard turns as the PVT or PTV or whatever that acronym is for the torque vectoring thingie. It felt (to me) like the computer was driving the car around the turn, not me. Sure, the performance is astounding, but somehow a bit disconnected.

So there you go.

 

I've driven mine pretty hard on very sharp curves on California Highway 9 here in Saratoga. I have done it countless of times and every time with passenger/padsengers in the car. It feels like it's on rails and tremendously confidence inspiring. I've got PDCC with SPASM but with PDK and chrono package.