I had to think about if for a while, but I think I'm seeing it this way now...although I'm not sure how much toe effect it really has (obviously depends on how compliant your bushings are)...certainly more under acceleration/braking than cruising down the highway

 

How do you do camber/caster? I bought the camber unit as toe in with a big lifted truck is as easy as measuring to the same point tread on the front and rear of the tires.

I will use your method for toe in/ toe out on the car, but I was more worried about camber for the vette. Good description However, nobody does a better job then yourself.

 

Based upon my reading of posts on the alignment subject over the past couple of years, most members seem to have experienced problems when having Dealers do alignments. IMHO, solution is to use a performance shop that has good Corvette experience. You're in NJ like me & I've used Phoenix Competition in Palm PA....not too far from you in Long Valley. On my '05, on the front they set caster at 7.85 degrees; camber at -0.45 degrees; toe at 0.02" (both sides). Rear camber at -0.48 degrees & toe at 0 (both sides). I've found these settings to be perfect for my driving style. Replaced the original GY Supercars at 18K miles with good tread depth remaining & now have around 5000 miles on Invo's with again, excellent wear pattern. Sounds like you already committed to your Dealer, but this approach is something to consider.

 

A couple of ways you can do camber, but caster requires special equipment which I have not fooled with.

Here is another DIY way:

http://www.pelicanparts.com/techarti...ome_toe_in.htm

Here a better explanation on theory:

http://www.ozebiz.com.au/racetech/theory/align.html

 

I got the same suggestion of using Phoenix from AO Roads after he read this post. I am definitely setting up an appointment with them after two recommendations.
Got the car back yesterday. The twitching on turn in is gone now but I can't wait to see if they solved the tire wear issue due to the cost of the tires. I'm getting a second look at the alignment.

Thanks for the inputs.

 

If you can measure camber, you can measure caster. Caster is just the amount of camber change as the wheel is turned. In other words, if you were to turn the wheel 90° to where it's now parallel to the axle (pointed to the side), the camber would now equal what caster was when the wheel was pointed straight ahead and caster would now be what camber was...the measurements flip-flop. Try to visualize it in your mind by looking at the ball joints and their position relative to the spindle and it'll become clear as you start turning the wheel.

We can use that to measure caster by turning the wheel XX°, measure the camber change, then multiply it by 90°/XX°. Let's say we turn the wheel 20° to the right then 20° to the left and measure a camber change of 3° between the two points. Our multiplier will be 90°/40°=2.25. This gives 3°*2.25=6.75°...pretty simple. There are also some tools out there that do the same thing allowing you to directly read caster off a scale that's already been factored or has a digital readout.
http://advantagewheelalignment.com/camber_gauge.html

There are many more companies with camber/caster tools and of course you can always make your own. I use the carpenters square like in your link above with a dial caliper to measure the distance to the rim then do the math myself using the inverse sine function. I haven't been to an alignment shop in over 30 years and certainly don't miss them. I like knowing what the settings are and being able to make small adjustments whenever I want to "tweak" the handling or tire wear. I can also change back and forth from race to street alignment in 30 minutes as many times as I want for FREE so I don't have to live with a "compromise" alignment.