Hi All, just bought a 2014 991.1 Turbo S a few weeks ago, love it, but due to the crappy weather haven't driven it very much. Overall experience so far is great but I have something going on that seems very un-Porsche.....at very slow speeds (parking speeds), when I turn the steering wheel hard left or right, I get what feels like a chattering noise/sensation through the wheel/car that feels like the tire is rubbing. Car has the stock OEM tires on it. So I went to my local Porsche repair house and they told me this is consistent with what they see....at low speeds, high turning radius, with the very wide tires the car is actually pushing the tire sideways. Something still feels fishy about this so wanted to see if others (all 991s???) have experienced this.

thanks, Jon

 

Normal, even caymans do it. Its due to the nice racetrack steering caster geometry we get. My winter tires dont do it, only my summers when its cold enough to change them.

 

Its the Ackermann Effect. You can read up on that if you like, it's perfectly normal

 

Just got my Pcar about a month ago and had the same "holy crap" moment almost immediately. No need to worry though - you're good. Enjoy the snails!

 

Thanks all....my 993 doesn't do it (even with the "toe" dialed up). What most freaked me out about it was I went into a 100 degree corner at about 35 and just cranked the wheel hard expecting the car to give me a bit of oversteer around the corner and instead the wheels locked up and went straight stuttering....not the behavior that is the most fun/predictable but I guess I need to play with it some more. Sure having cold tires all the time isn't helping

 

It only happens with summer tires in cold weather.

 

Normal.....but it can be disconcerting.....happened to me near a curb and thought I had hot my wheel on a curb.....thankfully NOT.....as said...Ackermann Effect....dealer called it "caster scrape"..

 

I have it on the 981 S...it's better with new tires. I have it pretty bad on the 991, that needs new tires.

Both are running extreme performance rubber, so we'll see if it's any better with new rubber when it warms up.

I just go slow and steady when backing up or slowly taking off with the wheel cranked until I get past Mr. Ackerman.

 

This is normal functioning with "summer" tires when the temps are cool/cold. If temps in your area are 40F or below, park the car or switch to "winter" or all-season tires.