Traction Bars

[Goatman]

Ok let's see.

250 lb/ft of torque (stroker motor going in within the month, no full throttle)

x 3.93 low gear x 4.0 t-case x 5.13 rear end x .85 = 17137 lb/ft

Nice to have 35 spline shafts, since I run mostly in 2low.

Rarely, if ever, get on the gas in 2low, so 17137 divided by 2 for both axles and then by 3 for the traction bar is 2856. How do you come up with a factor of 1/3 for the traction bar. If these calcs are remotely acurate, that is likely more than the ultimate axial load rating of that 3/4" rod end. Of course, in the real world I'm never close to full throttle, and there is usually tire slippage when I am on the gas a little, but it only takes one good bounce. Might look at moving it over closer to center and putting both rod ends in static load, although I've thrown plenty at it since it's been in there.

 

[MaXJohnson]

How do you come up with a factor of 1/3 for the traction bar.

The 1/3 is based on the length of the hypothetical traction bar in the example (36"). Your 8,568 ft/lbs = 8,568 pounds at 12" (1 foot) radius. for a 24" bar you would figure 1/2, 48" bar = 1/4, etc. You are dividing by the length(in feet for ft/lbs) of the lever arm applying the force to the chassis.

 

[Goatman]

The 1/3 is based on the length of the hypothetical traction bar in the example (36"). Your 8,568 ft/lbs = 8,568 pounds at 12" (1 foot) radius. for a 24" bar you would figure 1/2, 48" bar = 1/4, etc. You are dividing by the length(in feet for ft/lbs) of the lever arm applying the force to the chassis.

foot...pounds. So simple. :doh: