best way to get the most sparks

Add weight to your vehicle if you want more sparks. Make sure it lays so you are not a foot off of the ground with alot of crap hanging down that will fall off easily and hurt someone.
New grooved concrete is the best. Draggin on a road that has alot of seperations between the sections will rip welded/ bolted blocks off of your truck in a hurry.

Think about being safe before you go out and rail your ride. If you put another persons life or possessions in danger to have fun, you are doing it wrong.