I finally hooked the video camera up to the big screen today to watch my H/C runs. Well what felt to me like the tires spinning the first 8-12 feet turned out to be a totally different scenario.
While watching in slomo we saw that the car was hooked up tight for about the first 1 rotation of the tire then it starts spinning for about 10 feet then hooks up again. It almost seemed that it was hooked while the front was rising then came loose as the front traveled as high as it would go (tires still on the ground) then as the front started dropping it would hook back up and go netting 1.589-1.63 sixtys.
Now as to theories.
1. Stock torque arm flexing as it tries to lift the front tires off of the ground loosing pinion angle and traction.
2. motor achieving rpm enough to hit torque peak overpowering the tires.
Or something else? Let me know what you think.

 

The first thing that happens is the rim drops into the tire as the sidewall windsup and the footprint expands, then forward movement is exereted into the LCA then the axle housing trys to wrap and pulls on the torque arm. The angle of the LCA's determines the mecahnical advantage intersect point which determines the amount of lift on the front end. Since the angle is not highly adjustable in a factory suspension band-aids if you will help the chassis work better such as spring rates, shock valving and engine height. Whats happening in your case is hook and spin, when front end rise ends it unloads the tire. In my experience spin and hook is the fastest. I dont mean uncontrollable spin just 1.5-2 revolutions. Since your 60 foot times are good your combination seems to work well but needs some minor tweeking. I suggest working with tire pressure first. I would raise the pressure and get the tire to spin first, as the tire hooks it wont yank on the chassis as hard and front end rise and weight trasnfer will be more gradual therefore wont unload the tire. Go up 1/2lb at a time and keep the burnout consistant.

Kevin

 

thanks.