[Z06] Steering/Stability problem
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Joined: Apr 2006
Posts: 63
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From: Florida
Steering/Stability problem
I took my Z on my first extended drive this weekend. About 200 miles of flat 4-lane road. Had a couple of safe opportunities to take it up to about 120-130 mph and was surprised to find the car pretty unstable at speed. Lots of wandering, required constant steering input to keep her going straight. I noticed this to a lesser degree even at slower speeds, closer to the legal limit.
I haven't checked the tire pressure yet, but the front end seems tight, no play in the steering. Tires are relatively new (Firehawk Wide Ovals), I'm guessing less than 5,000 miles on them and they don't make noise like you would notice if the plies were separating.
The car has 22,000 miles on it. I've had it for a week. Any guesses/suggestions?
I haven't checked the tire pressure yet, but the front end seems tight, no play in the steering. Tires are relatively new (Firehawk Wide Ovals), I'm guessing less than 5,000 miles on them and they don't make noise like you would notice if the plies were separating.
The car has 22,000 miles on it. I've had it for a week. Any guesses/suggestions?
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Very common. Remeber your car is set up for legal street highway speeds not above 90 mph.
Ok Roads are crowned too allow water to run off. SO if your in the right lane the car will drift to the right or down the crown. If your left lane, the same the car will drift to the left or down the crown of the road.
if the road is bumpy or lots of cracks in the pavement that are running in the direction of the car, the car will fall to the lower level, again the car drifts.
Now taking the road out of the equation a few things to look at:
1- alginment. Do you have a stock alignement, agressive street or road racing alignment??? agressive street will help stabilize the car at higher speeds. Agressive street is the maximum of the standard street range.
alginment MUST BE EQUAL on both sides, not with in a range
2. tire pressure as you have mentioned.
3. Rake of your car. C5s and C6s need a 4-5mm rake, lower front then rear for proper aerodynamics at high speeds. Cars that are slammed may look cool but handle for chit. anyone who tells your differnt does not consistly drive at above 100 mph. I do all the time on a road race cirucit, but not on the public streets.
4. tire width - wider tires drift more on bumpy, crowned or roads with lots of cracks in the pavement.
HTH a bit
Ok Roads are crowned too allow water to run off. SO if your in the right lane the car will drift to the right or down the crown. If your left lane, the same the car will drift to the left or down the crown of the road.
if the road is bumpy or lots of cracks in the pavement that are running in the direction of the car, the car will fall to the lower level, again the car drifts.
Now taking the road out of the equation a few things to look at:
1- alginment. Do you have a stock alignement, agressive street or road racing alignment??? agressive street will help stabilize the car at higher speeds. Agressive street is the maximum of the standard street range.
alginment MUST BE EQUAL on both sides, not with in a range
2. tire pressure as you have mentioned.
3. Rake of your car. C5s and C6s need a 4-5mm rake, lower front then rear for proper aerodynamics at high speeds. Cars that are slammed may look cool but handle for chit. anyone who tells your differnt does not consistly drive at above 100 mph. I do all the time on a road race cirucit, but not on the public streets.
4. tire width - wider tires drift more on bumpy, crowned or roads with lots of cracks in the pavement.
HTH a bit
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Joined: Aug 2001
Posts: 5,364
Likes: 38
From: King George VA
Lots of good info from AU N EGL above.
I'll emphasize that the aggressive alignment, primarily the negative camber on the front coupled with the fairly wide front tires, makes the car really prone to hunting on rutted roads as many freeways are due to trucks tires. If your road isn't really flat, this is likely the main cause.
I'll add one thing to what he said above, and that is front toe. If your front ride height or camber has changed slightly your toe will change also. If the toe isn't correct the car can dart as the weight transfers slightly from side to side and the two tires aren't pointed in the same direction. A good alignment will fix this if it is the problem.
I'll emphasize that the aggressive alignment, primarily the negative camber on the front coupled with the fairly wide front tires, makes the car really prone to hunting on rutted roads as many freeways are due to trucks tires. If your road isn't really flat, this is likely the main cause.
I'll add one thing to what he said above, and that is front toe. If your front ride height or camber has changed slightly your toe will change also. If the toe isn't correct the car can dart as the weight transfers slightly from side to side and the two tires aren't pointed in the same direction. A good alignment will fix this if it is the problem.
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Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,821
From: Charlotte, NC (formerly Endicott, NY)
My 97 with Run Flats tended to hunt around a lot although a good wheel alignment tended to reduce the reaction to pavement seams, etc. My 03 Z with stock alignment settings (not in range but set right on with a touch of toe in on the front) doesn't wander at all. Its planted on the road at some very high speeds and it is shod with WOs also.
Bill
Bill
Team Owner
Joined: Sep 2003
Posts: 43,084
Likes: 33
From: Raleigh / Rolesville NC
Originally Posted by Bill Dearborn
My 03 Z with stock alignment settings (not in range but set right on with a touch of toe in on the front) doesn't wander at all. Its planted on the road at some very high speeds .....
Bill
Bill
