I have been rather curious lately at the wheel torque of a built Toyota with Low gears,
I have done equations for this kinda stuff and it doesn't calculate up right. My Question is, Given:
85' 22R with 129 Ft.-Lbs or torque,
G52 Transmission with a 1st gear ratio of 3.928:1
Low Range with 4.70:1
Crawl box with 2.28:1
Diff Ratio of 5.29:1
33 inch tires
Does anyone know how to calculate the wheel torque given these numbers? If I am right,
wouldn't these gears give you torque greater than that of a 350 Chevy to the wheels?
The simple answer is yes, with the dual ultimate gearing you're more than capable of putting more torque to the rear tires than a 350 Chevy.
If you assume 129 ft-lbs of torque @ 2,800 rpm
The theoretical torque to the rear wheels in low low 1st, ignoring losses, would be the following:
129 ft-lbs x 3.928 (1st gear in transmission) x 2.28 (low crawl box) x 4.70 (low t-case) x 5.29 (ring & pinion) = 28,724.3 ft-lbs
BigMike has done a write up on this in the past. The question is why don't things break and the answer seems to be that the torque is potential torque that is never realized. We know this because our axles have been proven to break at a much lower torque. Something always breaks long before the engine puts out that much torque. Also, the fact that we're geared so low pretty much eliminates impact loading from the drivetrain when the torque potential is that high. I'm fairly certain that if you had beadlocks and could lock your tires in place you could torque your front tires off the ground at idle if nothing in the drivetrain where to break.
I attached an old picture from Longfield that showed his axles and D60 35-spline axles breaking at under 8,000 ft-lbs of torque. If you don't break one then you have not exceeded this torque in your drivetrain.
