Lets do the math:
Ex. 3000lb car that has 50/50 wt. distribution and produces 400 ft. lb. of torque. The car has a Powerglide with a 1.82 low gear and a 4.88 rear gear.Torque multiplying factor is 2:1 (normal for a stock converter). Center of gravity is 19" and the whee base is 108"
Will the car wheel stand? First find the Drive Wheel Torque:
1) DWT= (engine torque x converter multiplication x first gear ratio x rear gear ratio x .85 (accounts for friction loss))
400ft lbs. x 2.0 x 1.82 x 4.88 x .85 = 6039.488 ft lbs (lets call it 6040)
2) Need to now know drive wheel thrust: wt.= DWT/TRR (total rolling radius)
The car has a 32" tall tire so we take half the diameter 16/12 = 1.33ft
wt= 6040ft lbs./1.33ft. = 4541.35 lbs. So we have 4541.35 lbs. of force pushing the car off the line.
3) G-force applied= WT/car wt. G-force = 4541lbs./3000lbs. (Car wt.) = 1.51G's
4) Longitudinal wt transfer =
Vehicle wt. x Center of Gravity height x G Force/wheel base
3000lbs x 19 inches x 1.51G's/108WB = 796.94
So now we know that we have 798.94 lbs. of weight transfer from the front to the back; the car is 3000 lbs and has a 50/50 wt. distribution which is 1500 lbs on the front. With a weight transfer of 796.94 lbs we can predict this car will not wheel stand. I learned this at a Dave Morgan suspension class.
Jeff (I definitely have too much time on my hands. I need a 12 step program immediately)