New Boxter Clunking Steering On Full Lock
Discussion
anonymous said:
[redacted]
You're right that it doesn't just apply to very wide tyres, but it's not JUST caused by geo (albeit geo is the major contributor - the front wheels depart further and further from pure Ackerman geometry as lock increases, meaning they have different turn radii and sideways slippage occurs). However there IS a contribution purely from the tyres. All tyres would need to be rotating faster on the outside edge than the inside edge when negotiating a turn (were such a thing possible). The outside edge of any tyre is negotiating a wider radius turn by a few inches than the inside edge so there's always some 'wind-up' in the tread blocks. The wider the tyre and tighter the turn, the bigger the discrepancy and the greater the effect.
Thank goodness for all your posts on this topic. Recently bought a 2016 981 (Boxster) and was horrified to hear a scrubbing noise on full lock. The Porsche Centre said "they all do that sir" (where have I heard that before) but it seems that they do. Thanks for putting my mind at rest. Thoroughly enjoying the car. I came from an XKR but prefer the Porsche!
Many thanks for posting this, you have brought my blood pressure back down to normal now.
I have had a Porsche Boxster 3.2 986 for 11 happy years and decided last week to go mad and buy a new to me 2013 981 2.7, I have never had anything but a wonderful driving experience with the old one, she has been much loved and much fun.
However the new one is prettier now I think, with its little pinched bottom and the 2.7 had as much power as any of the miserable road cameras or constant roundabouts would allow me, so I was sold.
A little later on wishing to show off my new acquisition to my husband, as we pulled off the drive and took a 90deg right, it did the pinched juddering clunking thing many of you describe, as if you are running over twigs or cobbles or something, we were thinking "WHAT THE FLIP…." thinking I had bought a duffer..( the horror, the possible expense!)
So I am MIGHTILTY relieved to read that this is "Normal" albeit a bit of a warning would have been nice, as it never happened on the old one!
I read its the "ACKERMAN EFFECT" some say cold, wider certain tyres affect this, we also have a Jaguar XKR supercharger and it as never done this...so I still find it odd, given we do have performance cars here but never experienced this before!
Anyway..thanks for this post, saves me a lot of time and worry!
I have had a Porsche Boxster 3.2 986 for 11 happy years and decided last week to go mad and buy a new to me 2013 981 2.7, I have never had anything but a wonderful driving experience with the old one, she has been much loved and much fun.
However the new one is prettier now I think, with its little pinched bottom and the 2.7 had as much power as any of the miserable road cameras or constant roundabouts would allow me, so I was sold.
A little later on wishing to show off my new acquisition to my husband, as we pulled off the drive and took a 90deg right, it did the pinched juddering clunking thing many of you describe, as if you are running over twigs or cobbles or something, we were thinking "WHAT THE FLIP…." thinking I had bought a duffer..( the horror, the possible expense!)
So I am MIGHTILTY relieved to read that this is "Normal" albeit a bit of a warning would have been nice, as it never happened on the old one!
I read its the "ACKERMAN EFFECT" some say cold, wider certain tyres affect this, we also have a Jaguar XKR supercharger and it as never done this...so I still find it odd, given we do have performance cars here but never experienced this before!
Anyway..thanks for this post, saves me a lot of time and worry!
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