Ricky,
You will want to first determine the natural frequency of your chassis. there are a few very good books on race char chassis design that will help you with that.
The racing surface is constantly changing, like a dirt road but more variable. If you imagine that on one dirt road there are humps every 1 foot and on the next road there are humps every 1.5 foot and the amplitude of the humps varies by 1 inch as well. Going from one course to the next or even the same course throughout a day can offer similar variations, though perhaps not to the magnitude in the example. As your vehicle changes speed, the frequency of the road bed humps remains the same but the response frequency of your vehicle is constantly changing.
The point is, you need to first work on developing a suspension that will work with the natural frequency of your chassis, regardless of minor variations in the road bed.