DIY Strings Alignment Setup Options

[yeahmag]

This was built using 80/20 hardware and a friend of mine on the mill:

[sww914]

I've done hundreds of alignments with computerized laser machines. About 80% of the time when I'd test drive the car the steering wheel would be crooked and I'd have to jack the car up and move the tie rods again to center the wheel. That's a bad sign. I've done a hundred alignments with strings and in 100% of the cases when I was certain that my measurements were perfect the steering wheel was straight when I test drove the car.
To set up the box around the car you measure to the hub of each wheel and make certain that the 2 front measurements are exactly the same and that the 2 rears are exactly the same and that the strings are perfectly parallel. If that's true and the car's suspension isn't bent you have a perfect box around the car to measure the toe. I also measure between the string and the chassis (not the body) of the car to make sure that my box that is parallel to the hubs is also parallel to the chassis.

It does matter if the floor is level. It really matters. If you set the camber and the floor is 1 degree slanted to the side it will change all of your measurements by 1 degree. Let's say the car is sitting at a 1 degree angle and you want your front camber to be -1 degree. You set your camber 1 degree negative on both sides using gravity as a horizontal plane. Now you move the car to somewhere where it really is level and you have 0 camber on one side and -2 degrees camber on the other side. Front to rear level is a lot less important but side to side is critical because every bit of difference in the floor will translate exactly into suspension inaccuracies. You can shim the ca's wheels with thin pieces of plywood to get it sitting level. Before I had a rack for alignments I had 2' X 4' sheets of 1/4" & 1/8" plywood that I could put in the same places on my floor every time to level the car. 4 feet is long enough to have plenty of room to roll the car after you make adjustments so the suspension can settle again.

I could get a vendor to roll an expensive computerized alignment machine into my shop on Monday but I don't want one. If you want perfect, strings are better.