High speed stability is very good. I notice no discernible wobble. I regularly do 80+ without high stability issues. It is important to torque any wheel spacer down so that is centered.
I must be missing something. You gained stability and gained oversteer? Please explain.
That's what I felt. Below is a more detailed response form someone smarter than me...
3) A wider track will lower the roll center at that end of the car, thus making it softer in roll. This is because the car's CG will not change, and thus the vertical distance between the CG and the roll center at that end of the car will increase, kind of like using a torque-wrench with a longer handle that pivots at the roll center. So a wider track at the front will make the front softer in roll which will once again tend to reduce understeer.
4) A wider track will tend to reduce the load transfer to the outside when cornering, which in general will increase cornering power since you'll be able to get more traction from the inside tires. So once again, increasing the track at the front will tend to reduce understeer.
So in general, making the track wider will increase cornering power -- but -- it is important to maintain an optimum ratio between the front and rear tracks as a means to managing the load transfer from the front to the back, and thus the resulting balance between the two ends of the car.
Now, widening the track using spacers also does a number of other things to the geometry...
1) It increases the front scrub radius, which can increase the steering effort and affect the feel and kickback.
2) It can increase the load on the bearings since the load will be cantelivered further out then the suspension designer may have intended.
3) Without working out the geometry, I'd also be concerned about causing the suspension to pick up a tendency to change track under bump/rebound which can cause all sorts of sudden strangeness in the handling as the suspension loading is changed.
