hai1206vn wrote:I thought I'd add another explanation for final drive. Think of the RWD drivetrain - the easiest to understand.
engine ---> tranny ----> differential ---> wheels
(By 'differential' I'm referring to the pumpkin block at the rear, which is not exactly what the term means.)
Engine drives tranny, which multiplies engine speed by a certain factor in each gear. (usually the output rev is less than input rev, but means more output torque). Let say your 1st gear ratio is 3:1. That means at the tranny output, your torque is tripled (but spinning at 1/3 the input rev)
What comes out of the tranny goes into the diff. In the diff, there one set of gear (ring & pinion) that again reduces rev and increases torque. The teeth ratio of the ring vs pinion gear is your final drive ratio. If your final drive ratio is 4:1, your input torque into the diff has been multiplied by 4. In total, your engine torque is multiplied by 3 x 4 = 12.
Finally whatever comes out of the diff drives your wheels directly. So in 1st gear the wheel is spinning at 1/12 the engine rev, but has 12 times the engine torque.
Ok this actually helped me. So what you're saying, is if my 1st gear has a ratio of 4:1, and my Final Drive Ratio (Which never changes?) is at 4:1, then my Torque would be 4x4=16 times what the engine is giving.
If ^^ is true, then that also means the Wheels are spinning 1/16th the Rev's of what the engine is spinning at?
Edit: Ok, I re-read your post, I think I just made up new #'s and used the same explanation