The start of a new year and a new diary – like always, the old diary has been moved to the Old Diaries page, use the above link.
Finally got time to tick some things off the to-do list, fortunately which didn’t require driving the car, what with all the rain we’ve been (finally) getting.
First was checking and setting rear camber and toe. When the rear rod ends were upgraded, the new ones were screwed in the same number of turns as the old ones, so I figured they’d be plenty close and didn’t bother checking alignment. During later drives though, the car definitely felt less stable – not a good feeling when your hands involuntarily tighten on the steering wheel. Another related issue is that the car had always required a constant bit of left-steer which seems a little odd. Regardless how the front toe is set, the steering wheel should be able to be turned to balance out any differences left-to-right, so there shouldn’t be any consistent pull in the steering (caster was fine). This is brought up because if the rear toe isn’t identical left and right, it applies a constant steering input that has to get countered by the steering wheel.
The first thing was to measure rear camber; the right rear was about -0.7 degrees which is about right, but the left rear camber was slightly positive… Not sure how it could have migrated so far. The lower A-arm was adjusted outward about 0.25″, which by chance resulted in the same camber as the right side.
Next was checking and setting toe, which is deceivingly simple. How hard can it be: measure the distance between two similar grooves on the tire, both on the forward and rear side of the tire. Turns out that it’s not that simple at the rear of the car. Depending the sequence of steps, rear toe may end up exactly “correct”, yet be totally wrong. How? Unlike at the front of the car where steering balances left and right toe, the rear is fixed. This means there are actually three dimensions that have to be set: total toe AND left and right toe off centerline. Unless toe from centerline is correct, the rear suspension will forever apply a steering vector which has to be corrected by steering. What a pain; due to the nature of suspension in general, I came this close to taking the car to an alignment shop. Not because the actual adjustments were difficult, but because the results were so squirrel. Setting total toe took hours because it would be adjusted, yet didn’t appear to change, so it was adjusted a bit more, then it changed too much. I’m fully aware of stiction and play, but the rod ends are all new and have no discernibly play, plus the car was rocked and the suspension resettled after each adjustment, but it was still elusive. Anyhow, at the end of an annoying day, rear total toe is 0.125″ and equal left and right.
Next was mounting the fire extinguisher. While I always intended to have one onboard, where to put it was a problem; every place was either deemed too accessible for seedy people, or it fowled my feet, or it was too inaccessible to be of any immediate use. I finally settled on attaching it to under the glove box. Haven’t decided whether to leave it there all the time or only for track events. Have to see how much it interferes with passengers’ legs.