Comment:

Lowering unsprung weight is the correct answer for the wheel cutouts.  In chassis design you have both sprung and unsprung weight.  The weight of the car is supported by the springs (or torsion bars), the action of the springs is controlled by the shocks.  All weight bearing on the spring plus half the weight of the spring and half the weight of the shock are sprung weight.  The axle, wheels, brakes, tires, and half the weight of the spring and shock are all unsprung weight.  Look at the suspension of race and even street cars.  Notice the body of the shock is always attached to the chassis.  Why?  Attaching the body of the shock (the majority of the weight) to the chassis makes that weight sprung weight.  If you had the body attached to the axle it would be unsprung weight.  So actually slightly more than half the weight of a shock is sprung weight.

Between the spring and the shock one can control how the weight of the car affects control.  I was a winged sprint driver so I have a better (but by far not perfect) idea of how it works on a sprint than a mod, but the basic theory is the same.  When you pitch the car in centrifugal force will throw the weight to the outside, simple physics.  Anyone who has swung their child in a circle can feel that action.  The car, just like the child, tries to increase the radius of the swing in an attempt to find the balance point where speed and centrifugal force allow a smooth arc.  Depending on track conditions you set spring rate and shock valving to bite into the dirt (side bite) stopping the slide (decreasing the radius).  At the same time you want the car to throw the weight to the inside tire to generate forward bite to get off the turn.  All this happens in just a few seconds but if the car is balanced you do not need to lift off the throttle (or maybe just burp it) to go through a turn.

By now you are saying, okay Fick, you're running your mouth but what are you saying?  We have controlled the sprung weight and have made it behave to our advantage, but the unsprung weight we have no control over.  As I recall from my days in the stands at The Square, the track stayed fairly tacky but had a tendency to get a little rough.  On such a track you would soften the spring rates as much as possible to allow the car to follow the ruts adjusting your shock valving to compromise between the soft jounce you would like to run against handling in the turns.  In other words you want to control the car with the weight.  However, the unsprung weight is not controlled, it hangs below the spring out of the control of the spring and shock package.  So when that unsprung balloon (tire) hits a rut it will act just like a ball rolling across a rough field.  In a turn the unsprung weight wants to leave the park instead of turn sharply.

Granted, the unsprung weight pushes against the sprung weight but it is doing so in an uncontrolled manner with unpredictable results.  Physics dictates that the greater the mass the more force it takes to move it and also the greater the momentum once in motion.  Less unsprung weight means less weight we have no control over, fewer variables making our car do what it wants as opposed to what we want it to do.

I hope this helps.  If you think about it at some point I promise the light will turn on.  A caveat, those who read this and have set up cars can pick holes through the entire thing because there are many more issues to consider which is what makes car set up far more important than horsepower.  I have no idea how many books I read on the subject of handling, engineering, and driving, how many chassis guys I talked to, and the volumes of advice given to me by Gambler.  So just be advised the story is much longer than this piece (and it is too long) but you get the idea.