Possible Ackermann Effect

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davlewis
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Post by davlewis »

Hey,

I know there will probably have been other threads so I will brace myself ..... however

I have noticed once or maybe twice (most recently this morning) when going though a car park and turning to reverse into a parking space there has been a kind of slight judder from the front wheels and it almost feeling like it's stalling. Does this sound like it might be Ackermann effect and is it something to worry about / bring up with OPC? (never experienced this before) ? :!: :?: I mean its very evident it happening and made me think WTF was that each time :?
- Macan Volcano Grey / Bordeaux Red Interior
- First time Porsche Owner

Madelvic
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Post by Madelvic »

Sounds about right. You'll feel it on full lock, forwards or backwards and in my experience gets worse as tyres wear
2017 Macan GTS Carmine Red
2005 Boxster S Artic Silver
AllanG
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Location: Southampton

Post by AllanG »

Madelvic wrote: Mon Jan 24, 2022 12:14 pm Sounds about right. You'll feel it on full lock, forwards or backwards and in my experience gets worse as tyres wear
Exactly the same as my experience.....I must admit the tyres ‘scrubbing’ noise doesn’t sound very nice, so I tend to avoid full lock if I can when the tyres are cold.
Allan
2023 Macan S in Crayon
PorscheMack
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Post by PorscheMack »

My Merc GLC had this and it reached epic proportions on a GLC forum as a significant number of owners were suffering. Merc eventually changed all 4 tyres and also in later models reduced the range of full lock which reduced/addressed the problem. This is a cold weather problem as during warmer weather or when tyres are warmed up it isn't noticeable.
Macan GTS (Gen 3) (Mar 24-???)
http://www.porsche-code.com/PRKIVM50
Macan GTS (Gen 3) (Mar 22-Nov 23)
http://www.porsche-code.com/PNIECDM4
chrisr111
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Post by chrisr111 »

We had an early GLC43 and front end 'skipping' was terrible when the OE MO spec Continentals were cold and wet. It progessively got worse with tyre wear and was downright dangerous in tight slippy multi-storey carparks when it used to go straight instead turning!

Merc fitted a set of BMW Star spec Contis FOC after the first set of OE tyres wore out, which improved things considerably.

We've had Macans for general family barge duty since the GLC went....

Chris.
MikeM
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Joined: Tue Nov 17, 2015 11:13 pm

Post by MikeM »

davlewis wrote: Mon Jan 24, 2022 10:55 am Hey,

I know there will probably have been other threads so I will brace myself ..... however

I have noticed once or maybe twice (most recently this morning) when going though a car park and turning to reverse into a parking space there has been a kind of slight judder from the front wheels and it almost feeling like it's stalling. Does this sound like it might be Ackermann effect and is it something to worry about / bring up with OPC? (never experienced this before) ? :!: :?: I mean its very evident it happening and made me think WTF was that each time :?
As OP’s state, not a fault just a feature with big treads especially pronounced in cold temperatures, not exclusive to Macan’s.
Previous Porsche’s
2008. 987 Boxster S Sport basalt
2012. 991 Carrera S aqua
2016. Macan Turbo volcano
Current
2020. Macan GTS crayon
2024. Macan GTS gentian sometime this year https://configurator.porsche.com/porsche-code/PR8H7WC6
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Wing Commander
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Location: Wiltshire

Post by Wing Commander »

I first encountered it when driving a Boxster courtesy car. Pretty alarming at the time!

As said above, it’s generally a cold weather phenomenon. It disappears as the weather warms up, or when winter tyres are fitted. :)
Simon

Sold: 2016 Rhodium Silver Macan 2.0
Sold: 2013 Platinum Silver 911 (991.1) C2
Sold: 2017 Carmine Red Panamera 4
Mine: 991.2 Carrera T Racing Yellow 06/04/2018
PorscheMack
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Joined: Mon Jul 12, 2021 3:46 pm

Post by PorscheMack »

It's interesting as I've had a number of SUVs but only experienced this on the Mercedes .
Macan GTS (Gen 3) (Mar 24-???)
http://www.porsche-code.com/PRKIVM50
Macan GTS (Gen 3) (Mar 22-Nov 23)
http://www.porsche-code.com/PNIECDM4
Deleted User 611

Post by Deleted User 611 »

Exactly the same issue and confirmed by a visit to the OPC. This is my third Macan and over seven years never experienced it before but the other Macan’s were on all weather tyres.
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Wing Commander
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Post by Wing Commander »

Jonnyw wrote: Mon Jan 24, 2022 6:15 pm Exactly the same issue and confirmed by a visit to the OPC. This is my third Macan and over seven years never experienced it before but the other Macan’s were on all weather tyres.

Yep, usually only affects cars on ‘summer tyres’, as opposed to winter or all season tyres. :geek:
Simon

Sold: 2016 Rhodium Silver Macan 2.0
Sold: 2013 Platinum Silver 911 (991.1) C2
Sold: 2017 Carmine Red Panamera 4
Mine: 991.2 Carrera T Racing Yellow 06/04/2018
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