DavidNJ

The regular Solo thread in the competition section recommends -1.5° in the front. Various posters and Karcepts recommends over -3° in the front and around -2.5° in the rear for a 255 square STR setup.

However, for autocross the car will only see a couple of dozen miles on the race track and a few thousand on the street (the car doesn't go in the winter and most of the time I need by QX56 for other reasons).

What do those high negative camber settings do for tire wear on the street? Are they essential on the track (my gut and my experience says yes)?

Thanks,

David

From Karcepts under their adjustable ball joint: "

• Suggested SCCA STR Alignment: 3.3 degrees front camber, max caster, 0" front toe, 2.4 degrees rear camber, 1/8" rear toe in"

Karcepts

That's a really good question David!

From our experience, tire wear will be fairly even at those settings, AS LONG AS you are able to hit up at least 1 autocross for every 150-200 miles of street use. And this also assumes you are driving the car at it's limits at the autocross. If you put more miles between events than that, you will either want to decrease front camber or start flipping tires.

If you want every ounce of grip, you will want camber at those levels. Tire wear under race use only will also dictate similar camber settings.

DavidNJ

Then the other side of the question, how much is lost from backing off the camber settings? What would be a setting for a car that seems 500, 1000, or 2000 miles of street driving per mile of autocross (BTW, autocrosses don't have much distance).

For a car with stock tire sizes running B Stock instead of STR, what would be the best street oriented camber with an occasional autocross?

In all cases the tires would be UTOG 200 rated: V2SS, RE71R, Rival S, RS3, etc. In STR for autocrossing, isn't a square 275/35-17 Hoosier A7 needed?

Karcepts

The only way to get an answer your first question is to test, then inspect tire wear.

In the B Street class, you cannot use camber kits, so you are limited by the OEM eccentric alignment bolts. You can get plenty of range out of the rear, but the front will be limited to a maximum of 1.8-2 degrees. Personally, I would max it out, and I'm pretty sure most S2000's in B Street do so.

STR class is limited to 200TW tires as well (most run 255 square).

DavidNJ

That would probably make this the tool to have:



It cuts a very small groove across the tread. That groove can be quickly observed to determine wear. It was originally an alternative to tire temps which are frequently changed by the time the car breaks to get off the track and drives into the paddock (Saturday night oval racing typically doesn't have a bit lane).

However, with today's 4-wheel laser alignments changing camber can be quite a project...or at least an expensive exercise. In oval racing, it is usually a quick shim in the front, doesn't affect caster, and toe-in is quickly reset with tape measures and toe plates. Accurate enough for a stock cars but maybe not ideal for a street car with IRS and where a camber change may effect caster.