For clay you have 2 picks, come to thousand oaks and take ALL the clay soil you want (
) OR you can go find a building supply place and beg and plead and see if they got any
. As for track designs, ooh boy leme call up some old pics (BTW not my pictures..... for everyones information), the designs are varied, someone (TechHead) had a great method of designing using circles..... half of the fun is designing and then the other quarters are building and RUNNING
If you want (im not the fastest but....) I can draw up a few designs if you want on graph paper and scan the images in if I know what your specifications are like:
Lane Width
Distance between lanes (i say about 1' or so to allow for piping.......)
How much area you have to goof around with
And lastly what kind of track do you want, a "bumpy one," a smooth one...... ya it helps
As for jump building:
Compactors + Water + Good dirt (no sticks.......) = good jumps if well taken care of [8D] Just make sure there are no watering restrictions for your area so you don't get slapped with a huge fine/may get on the page of your paper for bad reasons [>:]