After lowering, is there alignment specs to give the tire person that's doing the alignment?

 

Have him do a 2004 Z06 spec allignment

 

Thanks!

 

Here are the base C5 specs:
C5 Specs:
Front Individual Toe: +0.04 degree +/- 0.10 degree
Front Sum Toe: +0.08 degree +/- 0.20 degree
Front Individual Caster: +7.4 degree +/- 0.50 degree
Front Cross Caster: within +/- 0.50 degree
Front Individual Camber: -0.20 degree +/-0.50 degree
Front Cross Camber: within +/-0.50 degree
Rear Individual Toe: -0.01 degree +/- 0.10 degree
Rear Sum Toe: -0.02 degree +/- 0.20 degree
Rear Individual Camber: -0.18 degree +/- 0.50 degree
Rear Cross Camber: within +/- 0.50 degree

What you should note is the wide variance in allowed values. Take front camber as an example, which is nominally -0.2 but can vary from -0.7 to +0.3 and still be "in" spec. It is not unreasonable for a decent alingment shop to hit a target you give them within a tenth or so. For example, you can say I want my front camber to be -0.5 (slightly more aggressive than the stock -0.2 but still "in" spec. FYI, the Z06 spec is -0.7 +/- 0.5) and they should be able to get camber pretty darn close to -0.5. But, if you just hand them these specs and say I want it "in" spec, you could get stuff all over the place.

 

Subdriver, while at it, could you please post the Z06 specs as well? Also, what do you think would be best for Street/AutoX setup?

 

Z06 Specs:
Front Individual Toe: +0.04 degree +/- 0.10 degree
Front Sum Toe: +0.08 degree +/- 0.20 degree
Front Individual Caster: +6.9 degree +/- 0.50 degree
Front Cross Caster: within +/- 0.25 degree
Front Individual Camber: -0.70 degree +/-0.50 degree
Front Cross Camber: within +/-0.25 degree
Rear Individual Toe: -0.01 degree +/- 0.10 degree
Rear Sum Toe: -0.02 degree +/- 0.20 degree
Rear Individual Camber: -0.68 degree +/- 0.50 degree
Rear Cross Camber: within +/- 0.50 degree

I don't auto-x so I'm probably not the best source for the answer to that. You might want to post that question in the Autocrossing and Roadracing forum (which is hidden in the General forum).

Based on what I've read, a good auto-x setup is even more aggresive than my track setup because the course is so short and the turns so tight. Thus I think a setup for auto-x/street will be a compromise for both - better handling equals faster tire wear on the street. Where you fall on that spectrum is really up to you. How much tire wear are you willing to live with to improve your time on auto-x?

For handling, you want as much negative camber as possible. I run over -2.0 as an example. I believe auto-crossers run toe out in front, and lots of toe in for the rear, neither of which is good for tire wear. I run very slight toe out in front, and a little bit of toe in for the rear.

My suggestion is to run near the edge of the stock Z06 specs, but realize this will result in more tire wear than average.

Here is a suggestion which is within Z06 specs for a combination auto-x/street setup:
Front Camber -1.2
Front Toe: +0.05 degree (out)
Front Caster: Max possible matched side to side as closely as possible
Rear Camber: -0.8
Rear toe: -0.1 degree (in)

 

After lowering I had mine put back to specs for non Z06. Hopefully the alignment man knew what he was doing.