Initial alignment settings (warning: noob?)

[Flyinglizard]

If you want zero scrub, the front toe should be 3mm out at 3* camber. The rear should be the same.
Zero toe is not zero scrub. Some toe out rolls better.
10mm out, in the back will turn much better. If it is all rights, toe out the LR..

"Zero scrub" is when the camber thrust does not work against the other side/ The car rolls clean.
To check the scrub, set the tires at the target pressure(race pressure), tape down one 5ft long sheet of masking paper on a smooth flat floor. Lay another piece, over the first, about 4in shorter. Tape down the end closet to the car only, making marks with a pen on both ends of the paper to mark the starting position of the upper paper over the taped down ,lower paper. Roll the car over the paper, watch the paper slide on the taped down reference paper. Set the toe, until the upper paper does not move RE to the lower sheet. You cant back the car over the papers, because it will not roll backwards with out ripping the papers. (It is zero scrub in one direction only.)
The Miata , with 15x 22.5in tires needs about 3-4mm out, the VW with 13x21 needs about 3,mm.
It does change with tire pressure. check at the target pressures, cold does not mean anything..
HTH. MM

[pfcs]

Interesting way to "see" it Michael. A "ouiga" board gives the same interesting response to negative camber and asks you to run large toe-out to zero the board. (imagine how a loose tire rolls across the paddock: if 0 camber, it goes straight; the more it cambers, the tighter it turns in that direction; if a pair is on an axle and we increase the toe out, will they be happy going straight; is the actual/dynamic/loaded drag or toe -0- when we run this large toe-out with 2 and 3 degree cambers?)
I'm not sure, but it was quite interesting when I first discovered it. My spin-
It gave me a good reason to try more toe out at both ends of the car.
Street cars with large (say -2*) cambers don't seem to feather the treads at 0 toe but do when toed in or out-doesn't compute/doesn't fit neg camber=toe out model.
I tried coast down tests on the street w/my A2 from 40mph and longest rolls were at half of the toe that zeroed the ouiga board.
I used about those numbers on the car: .040-.060" @apex of sidewalls, frt and less in the rear.

[shwah]

Thank you Mike and Phil. I have been sticking with a KISS principle on alignment setup, but you have inspired me to play with toe and consider tire 'scrub'.

Great info.

[Hoof Hearted]

thanks for the responses... ...I'll try Chris' KISS set-up (I believe he might know "the set-up" for BHF). Weren't you four for four last September?

[shwah]

I did drop one on Saturday. Ran the race with the fuel setting too lean, and had a GREAT battle with Mike in the Yellow Golf. Sunday got to practice driving the track with two blown left shocks...

Good luck out there. I was hoping to make it out, but grad school is really eating up my time right now. If things go really wrong and you need help, post up here. I am about 80 miles from the track.

[Hoof Hearted]

Thanks for the kind offer Chris... ...I hope I don't need it!