[Don]

Comment regarding ballast weight from Grassroots Motorsports:

" If your under the minimum weight " " some teams use sheets of ballast as part of the floor design " " in the lowest portion of the chassis "

" Lead is a cheap and effective ballast weight at 708 pounds per cubic foot, but tungsten is a better and more dense alternative at 1224 pounds per cubic foot. However, tungsten comes at a price: It's sold for about $30 per pound, while lead is under $2 per pound "

First time I had seen a comparison on the physical characteristics of the two metals.