Could also be the torque vectoring...first time I noticed it in my C2S was a bit unsettling...but it's there to protect you.

Also could have the dealer check out the PDCC.

 

I've had cars with torque vectoring and have felt the rotation (B8 S4 & GTR). I don't think that's it because it kind of "shifts" on quick turns back and forth (even at moderately low speeds). As mentioned before, it's a DELAYED shift a split second AFTER turning, so it almost feels mechanical. Definitely reduced after reducing tire pressure, but I do worry if it's the PDCC malfunctioning.


That said, it could just all be in my head since it was there before. I just fear the rear will just kick out at speed on some back/forth twisties.

 

A little off topic but when you guys run the rears at 32 or so PSI, don't you get the yellow low pressure warning light?

 

I missed any reference to 32 or so. That would be too low for rears on a 991 IMHO. I run 35 cold in the rear and normal driving runs rears up to 38-39. I find that above that is not ideal. A 3-4 lbs differential between fronts and rears seems to work well.

 

32 for the rears is a bit low. I am a 4S on 20's and run 32F and 36R. I set the TPMS for comfort partial load and have never had an issue or a warning.

 

I am an engineer..they could not get away with broken as a root cause. Ask them what broke and why. Also ask the see the broken part. Finally ask them how sure they are the new part will not break again . if the answers are not satisfactory demand a failure analysis to be performed on the broken part. Come on man, tell them you can handle the truth.

 

Going to the track on Friday. We'll see if its all in my head! I bought the car in April certified - I know that doesn't mean they'll catch everything, but I would imagine they would have seen and addressed something catastrophic with suspension. Anyway, we'll see! Will report back after the track.

 

My previous Porsche was a 2004 Anniversary Edition that I drove on many of the same roads that I have driven my 2013 C4S on and I did find the cornering with the AWD and PTV configuration a little unsettling on my first hairpin corner on a mountain road. It felt as if the front end was "hopping" or understeer condition. This is my first AWD 911 so since the first couple of not so great hairpin corners, I find a little throttle helps to grab the road and the car pulls through the sharp corners without issues. Slight power on works best in the hairpin corner or a sharp 90° turn especially on a slight downhill. I am still slightly more cautious in a sharp corner than I was with the 2004 which was standard also with a LSD differential. As I drive more with this newer car I am sure I will get a better feel for what works in a sharp corner. I have never tracked a car so I have no idea what it would feel like taking sharp corners at speed. The YouTube video with Randy Pobst does not show any issues on the track. I believe this unsettling feeling only happens at lower speeds in a sharp corner (especially downhill) without the correct throttle input for the corner. Just a though as I am not an expert driver with a lot of 911 experience.

 

Does the car have SC mounts? I noticed the same thing in my 997.1 with standard engine mounts, but not in the 991 with SC mounts. And I've driven a 4S (no PDCC or TV) in the track and it was rock solid.

ChuckJ

 

Chuck, The 2013 C4S I have has the Sport Plus option and it has the manual 7 speed transmission. I believe with the Sport Plus package the engine mounts are the dynamic type and the Porsche Torque Vectoring is part of the package. I always drive in Sport Plus with the suspension setting normal (softer ride along with rev matching). Since my last post I tried the same sharp slightly downhill corner with more throttle and I get the back end to push out with good control through the turn, so that is the way I believe it should handle in such a corner. The previous hairpin corners may have been low speed, neutral throttle and too sharp a steering input that gave the unsettling cornering. At any reasonable speed it is rock solid through the corners and feels very planted.