Alignment Sanity Check

[FRSFirestorm]

Guys,
I'm fixing to put new springs on my car. Before doing so I've researched and done a couple string alignment measurements for toe to familiarize myself with the process and see if I get repeatable results. Goal being to do the alignment myself after the spring install.

Anyway I'm coming up with -0.9mm of total toe in the front. Within factory spec. My total toe is coming in repeatable but each wheel toe is different. I'm assuming it's because the wheels aren't always exactly straight when I string it.

Rear tow and the one I'm concerned about from the factory.... but within spec is a total toe of 3.0mm. Factory target is 2.0mm with a +/- 3.0mm tolerance.

Rear track is 1539mm. Front track width is 1519mm so I'm squaring the string 10mm closer to the rear wheels. (1539-1519)/2. I keep trying to convince myself that is wrong for some reason but I just can't.

What total toe should I shoot for front/rear after I put the springs on? The factory settings. Basically a street car. No tracking involved. Factory targets are 0 front and 2.0mm toe out rear. The rear just doesn't seem right for a factory setting..

Here are some pics I took with the last setup.

String down the passenger side.


String down the drivers side.


Setting string distance to center of wheel. 100 mm front. 90mm rear.


Taking measurements left/right of wheel.




TIA for any input!

[grodenglaive]

It should be 2 mm toe in on the rear, not toe out. Toe out would make it very unstable on the highway.
The string method has too many variables to be super precise, but I guess you can get a reasonable measurement if you're careful. There are easier methods that are just as good though, that don't rely on the f/r track width.

[FRSFirestorm]

I went back and checked my alignment sheet I've made up. I need it to reflect a negative sign with a toe in condition. The rear does have toe in. I had some sort of blonde moment when I got done, and re-inforced with the factory alignment numbers also not expressed in a negative.

I agree stringing a car is difficulty and agurably not the best way to go about this but it's the path I've chosen. I'm confident I can measure within +/- 0.2 mm. If I hit the factory nominal specs, and set up correct I'll be well within tolernance.

[d1ck]

I did a strong alignment and set about 2.5mm toe in on each rear wheel. I'm thinking this might be a bit too much as I'm getting a little bit of understeer. I might try 1.5mm or something instead.