Wheel alignment specs for street
Thread Starter
Melting Slicks
Joined: Mar 2001
Posts: 2,233
Likes: 5
Wheel alignment specs for street
My 98 cp has 20K miles. Tires have minor cupping on the front on the inside. What are good specs to have the shop set the front end for street/highway driving. Is stock G.M. what to use or ? Thanks, Skip :chevy
Burning Brakes
Joined: Oct 1999
Posts: 920
Likes: 2
From: Rogers, AR, USA
Re: Wheel alignment specs for street (skip89)
Here's my thoughts on alignment. I too had tire wear problems and was running on my third set of front tires by the time I acquired enough information about the C5 alignment to get things figured out, (I think). I set my own alignment in my home shop so I can try lots of settings with little expense.
First off, keep this in mind, you're driving a high performance car and a little aggressive tire wear is not out of line for a performance car running neg. camber, which is necessary to attain the cornering G-force ratings GM advertises.
According to GM document #776629, which gives alignment specs for the C5 & Z06, the (Preferred Front Camber is -.20 degree) for the C5 with FE1 & FE3 suspension. The (Camber Tolerance is +/- .50 degree). So if your front camber is anywhere between (-.70 degree to +.30 degree), you are within GM specs. You hardly need an alignment machine to get camber within that tolerance, that's easy hand level and eyeball range.
The Good Year run flat tires have a wide, square shoulder tread and a very hard sidewall which will put much more pressure on the edges of the tread, due to a small camber angle, and will result in what seems to be aggressive tread wear on the edges of the tread, usually the inside due to the neg. camber. Non-runflat tires have a much softer more compliant sidewall and is part of the reason the Z06 runs more negative camber.
The more square (0 degree camber) you set a wide tread tire, like the runflat, with the road, the less abnormal tread wear you will see.
I think it would be a wise move for GM to provide a set of "performance specifications" for aggressive driving, and another set of "touring specifications" for normal highway driving. They would need to provide a brief pro & con statement of the two specs and let the driver decide which way he wants his car set up.
So, back to the question as to what to use for good tire wear. Following is what I am currently running and with 11000 miles on the Stone RFT’s , there is no measurable wear variation in the tread.
Front
Camber: 0.0 degree, (error to the pos. side less than .10 degree if not exactly 0)
Caster: 5.0 degree, (steers a little easier and not nearly as important for street as it is for performance)
Total Toe: 0.1 degree pos.
Rear
Camber: 0.0 degree, (error to the neg. side less than .10 degree if not exactly 0)
Total Toe: 0.0 degree to neg. 0.1 degree
First off, keep this in mind, you're driving a high performance car and a little aggressive tire wear is not out of line for a performance car running neg. camber, which is necessary to attain the cornering G-force ratings GM advertises.
According to GM document #776629, which gives alignment specs for the C5 & Z06, the (Preferred Front Camber is -.20 degree) for the C5 with FE1 & FE3 suspension. The (Camber Tolerance is +/- .50 degree). So if your front camber is anywhere between (-.70 degree to +.30 degree), you are within GM specs. You hardly need an alignment machine to get camber within that tolerance, that's easy hand level and eyeball range.
The Good Year run flat tires have a wide, square shoulder tread and a very hard sidewall which will put much more pressure on the edges of the tread, due to a small camber angle, and will result in what seems to be aggressive tread wear on the edges of the tread, usually the inside due to the neg. camber. Non-runflat tires have a much softer more compliant sidewall and is part of the reason the Z06 runs more negative camber.
The more square (0 degree camber) you set a wide tread tire, like the runflat, with the road, the less abnormal tread wear you will see.
I think it would be a wise move for GM to provide a set of "performance specifications" for aggressive driving, and another set of "touring specifications" for normal highway driving. They would need to provide a brief pro & con statement of the two specs and let the driver decide which way he wants his car set up.
So, back to the question as to what to use for good tire wear. Following is what I am currently running and with 11000 miles on the Stone RFT’s , there is no measurable wear variation in the tread.
Front
Camber: 0.0 degree, (error to the pos. side less than .10 degree if not exactly 0)
Caster: 5.0 degree, (steers a little easier and not nearly as important for street as it is for performance)
Total Toe: 0.1 degree pos.
Rear
Camber: 0.0 degree, (error to the neg. side less than .10 degree if not exactly 0)
Total Toe: 0.0 degree to neg. 0.1 degree
