Car center line
 

Working on a DIY alignment and wondering if anyone has found a good way to find the car's centerline? If not, what are you using to reference?

(I know this should probably go in suspension but I figure most of the people doing DIY alignments are the autocrossers and trackers. Feel free to move it if you want)

I am having no luck trying to align my car using the classic string method on this car. Anyone else having any luck?

Create a box.

Take two poles and notch them on each end and put them in front and behind the car on jack stands. Measure the center of the wheel to the string and make sure the distance of the center of the wheel to the string is the same on each side of the car both front and back. This will define your "box". You can then measure the distance of the front of the wheel and the rear of the wheel in relation to the string and measure your toe.

I just did this to verify my normal "body-stringing" method was accurate on my race car. When I get a chance I will upload pictures to show you what I'm talking about.

Here's a good tutorial to illustrate what I'm trying to say. (This is not mine)

http://www.elantragtclub.com/id554.html

http://img405.imageshack.us/img405/3...52eclubul7.jpg

http://img409.imageshack.us/img409/5...54eclubfi4.jpg

http://img444.imageshack.us/img444/1...57eclubzw8.jpg

Thanks for the response. Curious on how you account for the difference in track between the front and rear?

So just to be clear, you have two perfectly equal distance notches in each of the poles on the front and rear of the car leaving you with a parallelogram and then you move the bars so that the distance from the hub on the front right and front left wheels are equi-distance to the string and then same for the two rears?

I could definitely see how this would be a fool proof method if you can accurately notch the two bars. It must take forever getting all four wheels to have the proper distance.

I was using difference in track given in the manual to measure the distance from the strings to the hubs but that is clearly not going to give me parallel lines especially with the addition of about 1* of camber in the front.

Any thoughts on how to accurately make those notches?

If your car has a wider track in the rear than the center of the rear wheels will just be closer or further away from the string but in an equal amount side for side.

Example:
Front Right=2.26" from string
Front Left=2.26" from string
Rear Right=2.66" from string
Right Rear=2.66" from string

Front rear delta = .40"
Difference in side to side = 0.00"

What you have is still a "box" because it shows an equivalency in the delta between string distance front-rear/side-side.

Some cars will use spacers on their rear or front to widen or narrow the track but this method, with the bars, is still effective.