Cold starts and wheels jumping
02-01-2019, 11:07 PM
#1
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Cold starts and wheels jumping
whenever I do a cold start and let it warm up and go to turn the wheels for the first time it jumps so bad and sounds horrible turning. ( while driving forward not stationary turning)
02-02-2019, 12:20 AM
#2
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2020 Huracan EVO AWD - 2022 GLE 63 S Coupe - 2023 C63 S Coupe -
If you are running wider than stock tires in the front and when it's colder it could be the "Ackermann Effect." It's basically Tire Chatter/Hop. Common in the C7 Vette, AMG GTR and others.
Ackermann Effect
Ackermann Effect
02-02-2019, 12:36 AM
#3
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Thread Starter
If you are running wider than stock tires in the front and when it's colder it could be the "Ackermann Effect." It's basically Tire Chatter/Hop. Common in the C7 Vette, AMG GTR and others.
Ackermann Effect
Ackermann Effect
02-02-2019, 06:19 AM
#4
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2020 Huracan EVO AWD - 2022 GLE 63 S Coupe - 2023 C63 S Coupe -
A car can still be prone/prevalent with stock tires as well. My GTR comes to mind. Actually, that is where I learned about this - on the GTR forum. Since I haven't heard of anyone mentioning this before on a C63 or another vehicle for that matter. Is why I brought up wider than stock. Doesn't mean you can't be experiencing it slightly with stock tires.
Last edited by benzbell; 02-02-2019 at 06:21 AM. Reason: text
02-02-2019, 02:09 PM
#5
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A car can still be prone/prevalent with stock tires as well. My GTR comes to mind. Actually, that is where I learned about this - on the GTR forum. Since I haven't heard of anyone mentioning this before on a C63 or another vehicle for that matter. Is why I brought up wider than stock. Doesn't mean you can't be experiencing it slightly with stock tires.
Thanks for sharing!
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02-03-2019, 01:14 AM
#10
I have no ideas about this, my rationale was the LSD opposes the turn in (becaus wheel 4&2 are locked) creating a YAW opposite direction to the turn in, this would cause the wheel with least traction to skip, in this case it could be wheel number 3 and you get your hop in the front caused by the diff in the back?
i have no idea about the setup of the suspension of the car just a guess... as I don’t see how Ackerman geometry causes it? Just interested in how it works?
02-05-2019, 10:33 AM
#11
I had this is my s5, and have it in my c63s now too, when very cold outside. Audi said it was hop, and it’s the same on the Merc with a sharp turn in the driveway or parking lot in the morning
02-05-2019, 12:25 PM
#12
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'15 C63S
I feel this all the time when making full lock turns, mostly when parking.
I always assumed it was due to the pronounced camber in the front wheels when at full lock (the edge of the tire rolling over, then not, then rolling over, then not).
I also assumed it was the main culprit for those of us that have issues with the inside edge of the front tires wearing prematurely.
I always assumed it was due to the pronounced camber in the front wheels when at full lock (the edge of the tire rolling over, then not, then rolling over, then not).
I also assumed it was the main culprit for those of us that have issues with the inside edge of the front tires wearing prematurely.
