I would suggest the following numbers as a good starting point for "spirited" driving.
Camber: -0.5 to -1.0 degrees
Caster: +2.0 to +3.0 degrees
Toe-in: 1/16"
The negative camber will provide additional "stick" at the front end, without literally peeling the rubber off the inside of the tires as you do the daily commute. That's not to say you can forget tire rotation... invest a few bucks in a tire depth guage if you don't already have one, and keep a close eye on wear.
The additional positive caster will generate more negative camber on the outside wheel, especially in lower speed (sharper) turns, with only a little additional steering effort. The positive caster also tends to stabilize the car on the straight bits.
I tend to believe that toe-in is mostly personal preference... more about how the car feels than how it actually corners... but suffice to say that for most cars (street or race, for that matter) I like fairly small toe numbers, be they in OR out. IMO, someone that's running a whole load of toe-in or toe-out (1/8" or more) and claiming it makes the car "handle better", is most likely compensating for some other problem in alignment, tires, or setup.
For calibration purposes, I can tell you the numbers above are actually quite conservative, depending on your perspective. On the ITB 142E racecar, I'm running -3.25 camber, +4.0 caster, and 1/32" toe-in. This is with stock suspension geometry, but Hoosier racing radials, 675 lb/in front springs, a 1.375" front bar and very stiff Carrera shocks. Extensive tire temperature data and tire wear patterns (not to mention laptimes!), tell us we must be very close to ideal for that particular car and driver.
Gary L.
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1971 142E ITB racer, 1973 1800ES, 2002 S60 T5
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