launch rpm with cal tracs

68 dart with 440,foot braking launching at 2500 hooks than spins 4 to 5 feet out.Changed pre-load, shock settings,tire pressure to no change

Weird because i'm launching off the foot brake at 3200 on a 29.5 x 10.5 slick, shocks set on 5, 1/4 turn preload, and on 200 spray and no spin at all.

The "hook then spin" problem w/ my car went away when I reset my front suspection for 5"+ of extension from the static ride height, as per Calvert instructions were when I explained what the problem was. Hasn't done it once since.

captain,I have 5" of front travel with calvert front shocks

What rear spring and shock combo. sounds like hitting tire real hard and then unloading. What hole is the bar in?

Jake,rancho shocks set at 5,stock 6cyl leafs,bar in upper hole.

Try the lower hole and add 2 clicks more rebound damping to see if that keeps the "hop" under control better.