This seems like a really bad way to DIY alignment

[matthew1]

Two accuracy failure points: the contraptions' straightness and the car's bumpers' straightness.

Manual Alignment.jpg (143.71 KiB) Viewed 835 times

Manual Alignment2.jpg (206.81 KiB) Viewed 835 times

[vtl]

It's alright, this is how it was done for decades, right? Some trigonometry formulas, and the method even works with non-parallel strings. Just measure everything as best as you can.

I did a spreadsheet with those forumlas a few year back, it worked fine for my AWD P2 unless the subframes were misaligned (which was the case with mine). The process is very tedious as it requires to setup and remeasure everything after a failed test-drive, so at the end I started to align the thrust vector be feel in many small adjustments and finally toe-in on both axles. Car never pulls anywhere, tire wear is even.

Of course that DIY alignment was a fallback after multiple incorrect (and expensive, hello Boston) shop alignments. I wish I've had their equipment in my garage...

[BlackBart]

Two accuracy failure points: the contraptions' straightness and the car's bumpers' straightness.

Exactly, I never trusted that stuff. It's ok to get it rolling straight enough to get it to a good alignment shop. I'm happy to pay the 80 bucks.

[vtl]

Exactly, I never trusted that stuff. It's ok to get it rolling straight enough to get it to a good alignment shop. I'm happy to pay the 80 bucks.

$80? Locals take $125, dealer was $170 a few years back. Nobody did it right.

[BlackBart]

I think that's a basic front end at my neighborhood tire shop. They have an old school guy who just does alignments.
But yes, I've had issues with them as well - couple of trips back to discuss the numbers on his printout.

[matthew1]

I'd look to anchor those parallel lines off something besides the bumper. It just seems like that would be one of the last pieces of a car I'd expect to be a plum 90°, especially on something 15+ years old... or 35 years old like in the pictured example.

P2 cars' front bumper covers are always suspect because they catch on parking blocks and pull off a bit.

[vtl]

The guy had to center it by measuring the distance from wheel hubs/caps before he even pretended he's doing alignment. This is written in instructions to any alignment rack of such design/principle.

[XC70Rider]

I've done multiple string alignments but only on 2WD vehicles. String was attached on jack stands. Nothing on the vehicles. You have to find the full span of the axles from right to left.