Porsche Macan Forum banner
1 - 20 of 52 Posts

·
Registered
Joined
·
92 Posts
Discussion Starter · #1 ·
Mine just feels like it has a tight diff or different turning arcs for the front wheels when using a lot of lock - particularly when going right out of a junction first thing in the morning. The front tyres seem to skip or hop to get back in sync with each other. Do they all do this? It can make for jerky and mechanically unsympathetic quick exits from junctions. Cheers
 

·
Registered
Joined
·
1,005 Posts
I like to have "apex fun" in my Macan, but I have not experienced the symptoms you describe. Does the behavior persist after it warms up?
 

·
Registered
Joined
·
795 Posts
When I test drove mine the salesman demonstrated a full lock turn in the parking lot, emphasizing how smooth it was at how it followed a circle perfectly. So I don't think yours should do what you're describing.
 

·
Registered
Joined
·
5,212 Posts
Do you have PTV?

I notice it once each morning on my way to the office, especially if the road is wet. Happens where I have to make a sharp right turn at a stop sign and accelerate a bit aggressively onto a busy road.

I have long assumed it's the PTV doing it's thing as it reminds me of what a mechanical limited slip diff would do in the same circumstances.

Feels like the right rear wheel loses and regains traction a couple of times. Perhaps not what you are describing as you mention the front wheels.
 

·
Registered
Joined
·
367 Posts
There is a definite lack of compliance in the Macan suspension both ends . It is most noticeable on the rear and on any bumpy road surface. It can be reduced quite a lot by reducing tyre pressures from the very high Porsche recommended pressures. I use 32PSI front and rear and would prefer 30PSI, but 30 triggers continual TPMS warnings. Give it a try in the circumstances where you experience the issues.
 

·
Premium Member
Joined
·
757 Posts
It's Ackermann. It happened with my Cayman. It does not happen with my Macan. My Cayman had summer tires. My Macan has all-season tires.
 

·
Premium Member
Joined
·
1,462 Posts
Yes

Mine just feels like it has a tight diff or different turning arcs for the front wheels when using a lot of lock - particularly when going right out of a junction first thing in the morning. The front tyres seem to skip or hop to get back in sync with each other. Do they all do this? It can make for jerky and mechanically unsympathetic quick exits from junctions. Cheers
I noticed the same symptoms you are expressing when I installed 21” Sport Classics with Michelin PS4 tires. Prior to installing this tire combo I had 19” Turbos with Michelin Latitude all season tires and never noticed this. This may be tied to stiffer sidewalls on the 21” versus the 19” tires but you can definitely feel a slight jerk in the wheel and not necessarily at a high speed. I would say it’s almost a skip in traction. :)
 
  • Like
Reactions: SoCalS5

·
Registered
Joined
·
35 Posts
I noticed the same symptoms you are expressing when I installed 21” Sport Classics with Michelin PS4 tires. Prior to installing this tire combo I had 19” Turbos with Michelin Latitude all season tires and never noticed this. This may be tied to stiffer sidewalls on the 21” versus the 19” tires but you can definitely feel a slight jerk in the wheel and not necessarily at a high speed. I would say it’s almost a skip in traction. :)


It’s Ackerman effect. Also occurs on Panamera and 911. Discuss it with your dealer


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #12 ·
Do you have PTV?

I notice it once each morning on my way to the office, especially if the road is wet. Happens where I have to make a sharp right turn at a stop sign and accelerate a bit aggressively onto a busy road.

I have long assumed it's the PTV doing it's thing as it reminds me of what a mechanical limited slip diff would do in the same circumstances.

Feels like the right rear wheel loses and regains traction a couple of times. Perhaps not what you are describing as you mention the front wheels.
No PTV mate. Definitely front end and on sharp rights.
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #13 ·
I noticed the same symptoms you are expressing when I installed 21” Sport Classics with Michelin PS4 tires. Prior to installing this tire combo I had 19” Turbos with Michelin Latitude all season tires and never noticed this. This may be tied to stiffer sidewalls on the 21” versus the 19” tires but you can definitely feel a slight jerk in the wheel and not necessarily at a high speed. I would say it’s almost a skip in traction. :)
Very similar - I have 21" and I have put PS4S on the front. It may be linked to these tyres (non N0 approved - but then so are many wonderful tyres out there and I need no nods to off road tyres!).
 

·
Registered
Joined
·
92 Posts
Discussion Starter · #14 ·
It's Ackermann. It happened with my Cayman. It does not happen with my Macan. My Cayman had summer tires. My Macan has all-season tires.
Thanks for the video grim. Does it have too little or too much Ackerman effect / counter effect?!

Looks like its a feature - wonder why it affects Porsches - have had Subaru AWD before and RR and they were all fine - not a 4WD thing?

Its REALLY unpleasant if giving it some beans out of a junction :(

Can anyone WITH approved N0 Latitude tyres and 21" confirm they get this too please?

Car has haa full 4 wheel alignment by a race guy so it can't be that - OMG so much better. [Took it there and he said' it's all in spec - give me 4 hours'! He knocked the front subframe over a few mil to get the front cambers equal, and got everything bang on perfect and matched each side - wonderful improvement]. I like my cars to be PERFECT - not this hop skip unpleasantness :(
 

·
Registered
Joined
·
5,212 Posts
I have definitely had that happen on my Turbo when I have the Conti 21 inch (N0 rated) summer tires on.

Does not seem to happen with the 21 inch Winter Scorpions (non N0 rated).

Happens first thing in the morning when I am maneuvering to get out of the garage and driveway.

Thought it might be an early sign of a failing transfer case, but maybe not.

Now that I understand exactly what we are talking about, I do recall from one of the Mercedes GLC forums that a number of GLC owners are upset about the same issue.
 

·
Registered
Joined
·
52 Posts
As others have said, Ackerman effect. Primarily caused by suspension design (improved handling / cornering) but tire compound, tire width, and outside temperature are also factors. Macan is very mild in this in my opinion - try a C7 Corvette with performance summer tires at 40 degrees. THAT will demonstrate Ackerman to you!!
 

·
Registered
Joined
·
343 Posts
Ackerman for sure, if at low speed on full lock, as demonstrated in the helpful video from @grim. Could also be a bit of understeer correction if you are carrying a bit of speed, which is "pushing" the front tires through the turn causing them to skip/shudder, particularly if you are accelerating and pulling weight off the front end through a corner.
 

·
Registered
Joined
·
5,212 Posts
Coincidentally just backed our M235 (with AWD notably) out of the garage (I also note that the OP has one, not sure with or without AWD) and got the same thing with the steering full lock to the left.

It's about 20 degrees (F) here and we still have the summer tires on (yes, the winters need to be put on, and it's on my to do list for tomorrow. 8 to 12 inches forecast here this weekend).

Felt like a bad CV joint, but I assume it's our friend Mr. Ackermann wishing us a good morning.
 

·
Registered
Joined
·
6,817 Posts
What is the Ackerman effect? I never noticed it on my Macans to my poor memory, but it happens on my current 911 and my prior one. I recall Nick Murray posting on YouTube that it occurs on AWD 911s which my first was. My current is RWD. I only feel it when backing out of my garage. I try not to turn full lock so it won’t happen.
 

·
Premium Member
Joined
·
757 Posts
What is the Ackerman effect? I never noticed it on my Macans to my poor memory, but it happens on my current 911 and my prior one. I recall Nick Murray posting on YouTube that it occurs on AWD 911s which my first was. My current is RWD. I only feel it when backing out of my garage. I try not to turn full lock so it won’t happen.
Lots of stuff on the internet about Ackerman. There are better explanations than I can give.

It usually happens when you are maneuvering in tight places in cold weather with wide, cold tires. It happened all the time when I was driving a Cayman with 20" wheels. It has not happened yet with my Macan.
 
1 - 20 of 52 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top