How would more or less unsprung weight effect handeling?
I'm not thinking about like going around a track, more along the lines of sudden up and down changes like hiting uneven section of road or drag launching with a car with all most enough power to lift the frount end.
What would puting lighter (or even heavier, more massive) parts in the suspention on the unsprung side of the suspention do?
I'm talking about parts like the frount LCA's, breaks, wheels, spindles and lighter rear end (saying if I could), you know the weight that the springs don't hold up.

 

This would probably get more response in Suspension, Chassis and Brakes discussion, but FWIW:


Less unsprung weight (mass) makes it easier for the spring/shock system to control the movements of those parts. Additionally, less massive wheels/tires mean less rotating inertia which improves acceleration/deceleration, as does the total lighter overall weight. There is almost no downside to reducing unsprung mass except for high cost, and a fairly low payback on the money spent.

If you want larger, more effective brakes and need a stronger axle to handle the power, and more massive tires to put it down, and maybe stronger suspension bits because you have higher g capabilities, you need to pay the price.

If you are talking about a street driven Camaro which is also raced on a road course, what makes it a good street car also makes it a lousy racecar. Overall mass (weight) whether sprung or unsprung is the enemy. Look at what GM goes thru to keep the Corvette, especially the upcoming 500 hp Z07 (or Z06) down to 3130 lbs.

If you are building an all-out racecar, concentrate on getting the suspension geometry right and at the same time making the suspension parts stronger AND lighter (and more costly). Otherwise, don't waste too much time and money on reducing unsprung weight, except for lightweight wheels, and perhaps brake discs with aluminum hats for your brake upgrade.

Better tires and more usable hp will probably drop you lap times more than most other things you can do.

My $.02

 

I had a local shop fabricate a complete front end suspension for my car. K-member, A-arms, etc.

Car was a lot nimbler and light on its feet. When going over bumps the wheels don't lose as much contact with the road as they would with heavier suspension pieces and higher rebound rates.