USAF-Vette

Just had my car aligned. Tell me what you think of these post-alignment numbers. The car drives very nice and smooth and does not pull; however, the steering wheel is not centered. That drives me a bit crazy.

The tech used the numbers I gave him:
Caster: 7.5 (front)
Camber: -0.45 (all around)
Toe: 0.0 (all around)

He said the numbers I gave him would cause excessive wear. From our conversation, he thinks there is too much negative camber and not enough toe-in.

Ric

Gearhead Jim

A slight amount of toe-IN will make the car feel more stable on the highway, and might help even out the wear that you get from negative camber.

Every time you go around a corner, the outside edge of the outside tire, takes the greatest load. If you have 0 camber, that edge will tend to wear quicker; so a little negative camber doesn't seem to cost anything in tire wear. Unless you drive like a total grandma...

EDIT:
On most (but not all!) alignment machines, a - toe in dicates toe-OUT and you don't want that. It wears the inner edges of your tires in a hurry, more than negative camber; and can make the car twitchy.
It looks like both of your right side tires have some toe-OUT, I wouldn't want that. The amount is small, but if there is going to be any toe then it should be toe-IN.

Your car is certainly driveable and you might not notice any unusual tire wear, but tires are expensive.
The steering wheel centering can be adjusted without changing the other numbers, but drive on different roads and different crosswinds to be sure you actually need an adjustment.

If the wheel is indeed off-center, I'd take it back and courteously ask for the toe and steering wheel changes.

USAF-Vette

So is the camber decent? Should I just have the tech adjust toe-in only?

Thank you!

By the way....another comment he made was: This is a "high speed" set up...not a "handling" setup.

BEZ06

with Jim.

Overall, your alignment looks fine for the street.

0° toe is okay, but a little toe-in both front and rear works good. For a street driven car toe-in up front also helps stability driving down the highway. Toe-in for the rear helps when accelerating out of a turn.

Here's Pfadt's excellent recommendations, and you're very close to the top one (and, as Jim mentioned above, most "negative" toe #'s indicate toe-OUT, but the Pfadt sheet identifies toe-IN by a negative #):

http://www.pfadtracing.com/blog/wp-c...-9.12.2011.pdf


As far as straightening the steering wheel - take it back and tell them to straighten it!!!

Or DIY like I did - just takes a few minutes:

http://forums.corvetteforum.com/c6-t...mine-pics.html


Bob

Jim Barker

Look up old treads about tire wear and there is a lot of reading on the subject. Best handling and best tire wear do seem to compete with each other. Except for front caster I have tried to Zero mine out from the factory specs to eliminate inside front tire wear. But it doesn't seem to handle the ruts in the road as well. I am curious how well the electric steering will perform on these truck troughs for the C7

I think the caster setting causes a lot of front inside tire wear on C6's because the back doesn't do it with the same camber settings. They do not lay over on the turns like the fronts. Geometry problem created by big wide tires, I guess just a thought!

USAF-Vette

Bob,

wouldn't your procedure also affect toe in/out?

Jim Barker

That's why alignment is touchy, toe is affected by the other settings and done last in the procedure along with straightening the steering wheel

Jim Barker

Bouncing the car so changes take affect and so on makes it sensitive to the adjustments when you only want 1/2 degree change. The wider the tire the bigger change a 1/2 degree makes for the dreaded inside tire wear problem or cupping that occurs on C6 and resulting noise, roar.

Jim Barker

On my long gone C5 it was rear tire wear that forced new tire purchases

Boomer111

Left side rear toe needs to be less and I would like to see a tad more camber all around, at least .1 to .2 all around.

USAF-Vette

So you are saying, change the camber from -0.45 to -0.55 or -0.65?

USAF-Vette

I'll take my car back to the shop tomorrow, but just for giggles...how much turning (retracting) would it take for the tie rods to bring the toe back in...1/8...1/4 turn each?

USAF-Vette

car back on the rack...tech will adjust toe only.

BEZ06

I think that's all you need - just a touch of toe-in front and back. For handling I use a lot more camber, but for highway driving I think your minimal camber will be okay.

As far as straightening the steering wheel - all you're adjusting is the toe. If you adjust the EXACT same amount both sides (one side in and the other out) you won't do anything to the overall toe spec.

Bob

USAF-Vette

Bob,

Here are the new numbers. He adjusted the toe, but also messed with the caster and camber. I know there is a range where the numbers can fall in, but how come he changed the camber and caster settings from the previous numbers (first post)?

I'm a bit irritated about that! Please let me know what you think.

USAF-Vette

One more thing....notice on the first print out it says 2009 Corvette (top left), but on the second print out it says 2007-2008 Corvette. Does that even matter?

Gearhead Jim

Specs are probably identical. Even if not, the ones you are using are good for your car and your driving.

USAF-Vette

Any other comments on the last print out?

Boomer111

More camber and less toe.

Google: Pfadt Street alinement specs for Corvette

I use this and am very happy with the handling and tire wear.

hungryhippo

The fronts should have more negative camber than the rears.