NV MY C5

So I went to get my Z aligned today. I was all prepaired and had all my specs written down. I gave them to the counter guy who returned a little while later. I was looking for about 3mm out in front and 2 mm in in the rear. He said their machine measures in degrees not mm's.
I made a quick phone call to a friend. He did some quick research and said 3 mms = 1 degree. I did the math and asked for -.5 degrees in front and +.3 degrees in the rear.
As they brought my car around he called back and told me that conversion was not right.
I brought the car home ( it drove very well!) and measured the toe. I have 1/4 inches out in the front and 3/16 in in the rear.
I dont drive the car on the street much, mostly autocross with race tires. Its more aggressive than I was looking for but what do you think? Is this going to cause any accessive tire wear?

Bill Dearborn

The spec is .1 degrees in the front with a +/- .2 degree tolerance. Your -.5 degrees is too aggressive for the street but may work out on an autocross course.

The rear spec is 0.00 degrees with +/- .2 degrees. At .3 degrees you may have a fair amount of outer tire wear. I had this setting on my 08Z for a few months. It helped settle the rear down when I was tracking the car. However, in 2K miles I wore out a brand new set of rear EMTs driving on the street. Even with -1.5 degrees of negative camber the outside edges of the tires wore out.

Run it at an autocross and see how it feels. You can make your own toe adjustments. The front isn't as critical as the rear since the steering wheel will turn to center the tires. In the rear you have to be more exacting in your adjustments as they affect thrust angle as well. Here is a toe graph that will help you go from inches to degrees at each wheel: http://www.smartracingproducts.com/p...e_settings.pdf .

To set thrust angle buy a 2 ft long Sears Digital Laser Level cost ~ $70. Set the level on the side of a rear wheel with the laser pointed to the front. Then have a helper insert a tape measure through the front wheel spokes so the end contacts the frame (I have some white paint on my frame right around the brake duct mount) and point the laser at the tape measure and write down the point where the beam hits it. Do the same on the other side of the car with the tape measure hitting the frame in a similar position and mark that measurement. Adjust the rear toe to get the toe in you want (I use toe plates) and to make the readings at the front equal. This will take some back and forth as toe affects thrust angle. You have to move the car between adjustments to settle it. Just make sure the last move is forward before taking any measurements.

Bill

sperkins

Way too much toe out for the front. You'll burn through the front tires in no time.

Kubs

My street setup I run 0.00" of toe in the front and 1/8" total toe (1/16 on each side) for track. I think 1/4" is way too much for the front.

NV MY C5

Thanks for the input guys! I adjusted each of the tie rods 2 flats and remeasured. Ive got 1/8 in the front and 1/16 in the rear. Im much happier with that. I am going to get a level from work and check the thrust as you suggested Bill.

Thanks again!

autoxer6

For autocross, 1/8" up front is a good setting.

You can play around with the rear setting depending on your set up and style. More rear toe in will keep the rear end more stable under power. Less rear toe will let you walk the rear around the corner more. Typical range is 0 to 3/8".

thehammer69

I have my toe set on my Autocross car at 3/32" OUT up front and 3/16" IN on the back. Running less than 1/8" toe IN in rear with stock rubber bushings is a recipe for that *** end of you car jumping out on you when you don't want it to. You should have left your rear toe where it was. My humble opinion of course.

naschmitz

Been there. Done that. It's true. Especially with r-compound tires.

mashinter

I watched a serious autocrosser adjust his toe at the event. He dialed in toe out up front for the event, dialed it out for the road. It is very easy on a C4.

Kubs

On my C4 I remove "x" amount of shims and not only does chamber change but it puts the toe where I want it. When I drive on the street the shims go in and the toe is 0 in the front. To do this I found what I wanted my race settings to be and then just added shims until I had zero toe for the street. The rear is easy thanks to Banski's kit. I just rotate the adjustable sleeve "x" amount of turns to get the same effect. I can go from street to race alignment in less than 5 min in the pits.