great minds again ... this was my thought also ... very much fits the description of the symptoms

 

Sorry about the confusion on what the car is doing. I'm just not sure how to describe it. Basically, when I hit a certain bump or camber in the road, I "feel" the car trying to move to the right. The steering wheel would turn from a straight line to probably a few degrees to the right, maybe half way to the one o'clock position. Then I just bring it back. That's why I said it was almost trying to catch it. I feel the movement is coming from the back and not the front even though the steering wheel seems to move. All the tires are Pirelli Pzeros and were all replaced at the same time. In any case, I'll be bringing it in to my dealer and they did agree to look at the whole suspension again. I'll keep you guys updated, thanks again

 

Hopefully the blue shipping blocks were removed from the suspension during PDI.

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Pireilli's tramline quite a bit IMO...

 

Yeah but if that's what it was the car would be doing it both directions, following ruts and seams not responding to bumps. Its interesting he feels the movement is coming from the rear. I'm not certain about the 991 but from the 993 on the rear suspensions have been designed to introduce a bit of toe in as they compress. They overdid it on the 993 but pretty sure they kept the trait just modified it down some. What this does if you think about it is introduce stability by countering the tendency to oversteer with a little toe in. Anyway, if this was out of adjustment it could be causing too much toe change on one side resulting in steering needed to correct this, which is what he's described. Of course its probably something else, just this is the only thing I can think of that fits everything described. Another thing about it, it would not be evident on a static alignment rig, as the alignment would need to be checked under compression and partial load as well as at normal ride height.

Now after all that it will turn out to be some dumb PTV fault code….

 

sounds plausible

 

I agree with all the advice given. This is a real poser. Your avatar says you are in Fla. The car isn't at your winter home in Colorado is it? I have the same car with the same tires. I foolishly took it out with temp in the teens and it was weird enough that it scared me. They don't call them summer tires for nothing. The tires are new to you, but when we're they manufactured? Would'nt the camber always be falling off to the right in countries with left hand drive? I would measure the distance from the centerline of the rear wheel to the c/l of the front wheel....should the same on both sides. I would jack the car up and spin each wheel to check for runout. Usually you would feel a problem on the front wheel, but with electric steering I'm not do sure. Good luck....Chris

 

Could just be a feeling of the 911 weight distribution that you're not used to? It definitely feels very different than a Cayman.

 

I just hope this doesn't turn out to be another one of those times when after all the puzzling symptoms we never do learn what it was, what fixed it, or indeed if there really ever was any problem at all. Anticipation … anticipation… is keeping me waiting…

 

Keep in mind that if you are used to tracking a Cayman, the 991 Cab is going to feel wishy-washy because your chassis of the Cayman is easily twice as stiff and on a shorter wheelbase. Rather than chasing what may be wrong on your cab, you need to take another one out and see if drives like yours. That will tell you pretty quickly if yours is in spec. Cutting the roof off means lots of chassis flex.

 

+1

 

Not to be picky but the 981 has a longer wheelbase than the 991.

 

+1

 

Alright...alright...you guys win on the technicality because I didn't read carefully enough! I thought the OP came from a 987 Cayman which specs at 95.1". Turns out he moved to the 991S (96.5") from a 981 Cayman (97.4") so I stand corrected!

I'm still thinking the loss of appx 50% chassis stiffness may be what is making the car feel odd vs the 981...

 

Not odd. Asymmetrically odd. That's the key. Odd to the right, not odd to the left. His descriptions are all over the place, but one things been constant, its to the right.

Of course now we will learn its to the right because roads are crowned, and he was just hyper-sensitively misreading normal steering feedback. Or… TPMS said the front right was 33, when really it was 23. Or...the OP disappears and three weeks later the threads still going, everyone long since forgotten there ever was a guy who said his car slides to the right…. from the rear…. anticipation….