AutoCross Tire Width

[JayR]

A very good basic rule of thumb is to not have too big of a disparity from front to rear when prepping a car for serious cornering.

For instance, a mini-tubbed car with 335s out back that can only accommodate a 245 in front and maybe an iron headed BBC sitting over those 245s is pretty much guaranteed to "push" or understeer at the limit because the 335s will stay hooked and if the car wants to slide the fronts will be doing all the sliding which makes steering difficult at best. There's exceptions to every rule which is why I prefaced that sentence with "for instance" but it illustrates what you should be wary of when planning and building. You can tune out some of those characteristics with sway bars and spring rates, etc but physics are physics.