Originally Posted by radio_car_racer
adjust the camber turnbuckle until your happy that the gap between the rim and the straight edge is the minimum you can get after spinning the wheel a few times.
Adjusting front camber to eliminate coneing is a pretty basic part of setting up any pan car. This is not what most would call uneven tire wear -- the term used is coneing. The target is with a small amount of negative camber -- as the tires wear, the amount of negative camber required is reduced.
Uneven tire wear happens on most race tracks (Suzuka in Japan is an exception) because there's more turns one way than the other way. In general, road course races are run in a clockwise direction, while oval races are run counterclockwise. It's pretty basic coming to the realization that on oval cars, the tires on the right hand side of the car wear quicker than the tires on the left. Similarly, on road course cars, the left side tires generally wear quicker than the tires on the right.
Simply rotating the tires from one side to the other every race will tend to even out the tire wear, but nonetheless, they will not wear entirely evenly. Also, the placement of gear on the chassis will affect the cross-weight, which is what the tweak adjustment controls.
One of the important lessons I've learned in my years of racing 1/12 scale cars is to always check the tweak after adjusting the ride height. Adjusting the shims in the front, no matter what shims you use, will cause a slight change in the cross-weight of the car. Swapping out rear bearing excentrics will also cause a slight change, since no two parts are truely identical. If you're used to a car that handles well, throwing your car on the track after adjusting the ride height and not tweaking the tweak is sure cause for a 3rd place finish at best.
Pardon me for being skeptical, but the above is just my experience running a few T-bar cars (Associated 12L and Revolver), as well as the CRC Carpet Knife. True, I didn't throw my 1st 1/12 scale car (an Associated 12i) on the board much, but since it didn't have provisions for adjusting tweak, there wasn't much point. It's also true that a Carpet Knife could run circles around a 12i. Although I've never run a Corally, one advantage of that chassis is the lack of tweak adjustment.
If the BMI truely doesn't benefit from a tweak adjustment, that's pretty cool. However, unless the chassis is laid out in a way different than how I think it's laid out (I've yet to see one in person), it seems to me that this may come back to haunt the design. As mentioned previously, this adjustment is critical in my experience for fine tuning the adjustment of the chassis after changing ride height. Not only that, but on some track lay-outs, it can be advantageous to run a little wedge (the term used when you intentionally run a little bit of tweak). If there's no provision for adjustment, than this go-fast tuning trick just doesn't apply.
Besides, rotating tires every race is a pretty big pain in the butt when you're running the race day as well. Not only that, but this technique definately will NOT work if you're runnnig two classes with the same chassis -- you'd need one set per class, and it would be a major inconvenience (not that I do that).