Quote:
Originally Posted by okiranger
BUT!!!! what is the torque to the wheels when 4low is engaged.

The total torque to the wheels will be what the engine actually puts out times every torque multiplier minus the drivetrain friction.
Making some arbitrary assumptions about the drivetrain will allow us to do sample torque calculations. Note that these numbers aren't necessarily true for a Ranger or for any other vehicle. They are just assumptions of possibles used to demonstrate the method:
 total frictional loss in the drive train of 15% for a 4x4 manual and 25% for a 4x4 automatic.
 torque converter factor of 1.8
 the RPM at which the engine torque peak occurs can be made to coincide with the RPM that yields the converter's peak torque multiplication (this may not be realistic because the stall speed and peak engine torque often occur at different RPMs).
Examples:
Automatic:
238 lbft. advertised torque peak
2.47:1 first gear
1.8 peak converter multiplication
2.48 transfer case reduction
4.10 axle ratio
75% drivetrain efficiency
Max torque in 1st gear and low range:
(238 x 2.47 x 1.8 x 2.48 x 4.10) x 0.75 =
8069 lbft.
Manual:
238 lbft. advertised torque peak
3.40:1 first gear
2.48:1 transfer case reduction
4.10:1 axle ratio
85% drivetrain efficiency
Max torque in 1st gear and low range:
(238 x 3.40 x 2.48 x 4.10) x 0.85 =
6994 lbft.