Bloody long day... Prepare for an episode of suspension setting DIY style.
To set the suspension correctly, all 4 wheels have to be at equal height. At very least left-to-right levels have to match, otherwise there will be funny diagonal tensions and that will mess everything up. So first step was to insure that floor is flat. For that I used a trick I saw in youtube, this is how it works.
It's a bucket of water, a clear tubing with one end in the water and another one taped to a ruler. If you don't move the bucket, the gravity will make sure that the level in the other end of the tube always matches the water line in the bucket. And because it's taped to a ruler, I can put the ruler anywhere on the floor and read the difference in height! It's genius in its simplicity.
Results of my measurements
Since the tubing was rather short, I did four measurements, comparing both sides back-to-front and both axles left-to-right. The result I got was that the front was pretty much level (right side 1mm higher), the rear is about 2cm lower, with right side 0.5cm higher than the left.
To roughly level the car I used some leftover parts from IKEA
Board for the right wheel I got from their crap corner for 50c, and the thicker one for the left wheel was a leftover from my speaker stand
project.
With the car level, I adjusted the ride height. Ideally, this should be done with someone in the driver's seat, but my goal was to do toe-in and camber today, so I can tune height at a later point without affecting wheel angles when I have someone to weight the car down. So for now the car is leveled dry.
Another little patent for measuring height, an adjustable furniture leg with a bolt
I slide it under the car, turn the bolt until I hit the chassis rail, remove my gauge and measure it. Then compare to the other end. Height is varied by adjusting the spring platform on the shocks.
That sorted, it was time for wheel angles. The rear is obviously fixed, being a live-axle. So I used rear wheels as a reference to set up the fronts. I ran a piece of string stretched alongside the car, and adjusted it so that it's strictly parallel to the rear wheel.
Using the string I can adjust toe-in, but for camber I needed vertical reference. For that I bought a cheap laser line level.
here it is aligned with the string, making a wall of laser beam, so to speak. Obviously, it's not visible here until I put the ruler in its path.
And that's how I measure the angle. Take distance from the string or laser beam to the one end of the rim and then the other. One trigonometric operation later the wheel angle is obtained. For toe-in it's front to back, for camber it's top to bottom.
Toe-in is easy, just rotate the shaft of the steering rack, and lock it with a bolt. Done. But the camber needs to be adjusted by rotating the endpiece of the top wishbone with a balljoint. For that, the balljoint has to be popped out of the upright that wheelhub is bolted to. The bolt is a conical shape, such that when the nut is tightened, it's forced throught the ear of the upright and stays in there by friction. Which leads to a problem of removing it, because the thing is STUCK there. Normal way of solving the problem is a big hammer, but mine was either not big enough, or I'm too much of a pussy to swing it hard enough. Which is why I fashioned this tool for popping out the bold of the top balljoint:
It fits nicely between the centre of the wheel axle and the bolt of the top balljoint, and then I just unscrew it until the balljoint bolt is forced out. Here's the picture when it's already popped out:
Immediately I noticed a problem, the rubber boot on the balljoint was fucked. Luckily, I have a second set of top wishbones! The one on the left was destroyed in the crash, so I bought a full set, and only used the left side of it. But the right side balljoint was perfectly fine, so I swapped them.
That tape there is just to hold the nut in place, it's marking a position for the correct camber setting.
Top link disconnected, adjustment in progress:
And the left side I did about 4 times faster
The values I've chosen after reading through dozen of threads on blatchat were 1deg negative camber and 20min toe-in.
Overall, I think the toe-in is accurate enough, but camber is a little unsure. The laser level is, well, crap. 10 euros, what can one expect. The precision of bubble indicator is quite poor, and it affects the angles a lot. So I probably will bring the car to a shop to have all angles measured at some point, with me in the seat. Using that data I can accurately make corrections myself. But at least I'm in the right ballpark now.
Then... I had a few hours left in this day, so I thought I'll trim the exhaust exit a bit.
And after an hour of filing, this is the result. I might come back to it after the exhaust leakage is fixed, and maybe trim it a bit into a more natural shape, to have equal gap all around the tubes. For now, as long as exhaust clears the bodywork I'm happy.
Yes, the bimmer is HUEG
Getting there, getting there....