Front End chatter
Thread Starter
Evolving Member
Joined: Feb 2009
Posts: 116
Likes: 2
From: Aloha, Oregon
Front End chatter
I just noticed a problem, which I am not sure has always been there. My front end chatters when I turn the steering wheel all the way to the lock, like when I'm pulling into a parking space. The chatter is barely noticeable when my ACD is set at "tarmac". It gets worse on "gravel", and is the worst on "snow". So I guess basically, it gets worse the more power I distribute to the front wheels. Does anyone else have this behavior on their car? My car is a 2006 Evo IX MR.
Joined: Apr 2005
Posts: 9,002
Likes: 12
From: somewhere testing various tires, brakes, and suspensions.
The ratio is 50:50. You are not applying more drive power to the front.
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https://www.evolutionm.net/forums/ev...everybody.html
Thread Starter
Evolving Member
Joined: Feb 2009
Posts: 116
Likes: 2
From: Aloha, Oregon
I don't know what fluids are in there. It's whatever the last service shop put in. The power ratio, I believe, is:
Tarmac: 60% rear, 40% front
Gravel: 50% rear, 50% front
Snow: 40% rear, 60% front
That's what the ACD switch does for you.
Tarmac: 60% rear, 40% front
Gravel: 50% rear, 50% front
Snow: 40% rear, 60% front
That's what the ACD switch does for you.
Joined: Apr 2005
Posts: 9,002
Likes: 12
From: somewhere testing various tires, brakes, and suspensions.
Originally Posted by Terry S
D. How the Tarmac/Gravel/Snow switch influences the ACD
Despite popular belief, this switch DOES NOT change the torque split. The differential is geared at 50:50 and cannot be changed by the push of a button. What this switch actually does is quite simple. Each setting determines how long the ACD will delay in freeing the center differential after a steering input is made. In addition, it will determine how much locking force the ACD will exhibit on the clutch pack and center differential. (10) (11)
Tarmac is the setting to be used in dry, paved conditions. In this setting, the ACD will almost immediately allow the center differential to go into a free state upon detecting a steering input. Additionally, this mode provides the strongest limited-slip clamping force of the three modes. (7) (12)
Gravel is the setting designed for wet or loose roads. In this setting, the ACD will delay in freeing the center differential for a moment (possibly 2-3 seconds). Of the three modes, this one has the second strongest clamping force. (7) (12)
Snow is the setting designed for, you guessed it, snow. In this setting, the ACD will delay in freeing the center differential for much longer than the other two settings (possibly 4-5 seconds). Of the three modes, this one also provides the least amount of clamping power. (7) (12)
Despite popular belief, this switch DOES NOT change the torque split. The differential is geared at 50:50 and cannot be changed by the push of a button. What this switch actually does is quite simple. Each setting determines how long the ACD will delay in freeing the center differential after a steering input is made. In addition, it will determine how much locking force the ACD will exhibit on the clutch pack and center differential. (10) (11)
Tarmac is the setting to be used in dry, paved conditions. In this setting, the ACD will almost immediately allow the center differential to go into a free state upon detecting a steering input. Additionally, this mode provides the strongest limited-slip clamping force of the three modes. (7) (12)
Gravel is the setting designed for wet or loose roads. In this setting, the ACD will delay in freeing the center differential for a moment (possibly 2-3 seconds). Of the three modes, this one has the second strongest clamping force. (7) (12)
Snow is the setting designed for, you guessed it, snow. In this setting, the ACD will delay in freeing the center differential for much longer than the other two settings (possibly 4-5 seconds). Of the three modes, this one also provides the least amount of clamping power. (7) (12)
https://www.evolutionm.net/forums/ev...everybody.html
Thread Starter
Evolving Member
Joined: Feb 2009
Posts: 116
Likes: 2
From: Aloha, Oregon
Wow, thanks for the link and for setting me straight on that point. I don't remember where I got the idea that the ACD provides a 60/40, 50/50, 40/60 torque split. I must have read it somewhere and just made it a "sticky" in my brain. Does anyone know how this misinformation got out, because I am sure I saw it in several places. But back to my original prob, is the chattering (ie skipping) normal in the snow setting? Does anyone else see this behavior?
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