What am I doing
Hi everyone my first post. I have a 2002 Chevy 2500HD 3/4 ton 4.10 gears that pulls our 4,000lb (fully loaded) 18' expandable trailer like a dream. On all but the steepest grades I'm able to keep arou...
Forum Discussion
Torque is the twisting force...normally referred to in Ft/Lb (foot pound)
HP, Horse Power, is what work that torque can do. Components are torque, RPM and
a simple algebraic formula: HP = torque x RPM / 5252 (torque multiplied by RPM
divided by 5252
A transmission multiplies or changes the input RPM to whatever ratio to the
output. Can be higher or lower depending on the ratio
So if the ICE develops, say 100 ft/lbs at the flywheel...it can have more or less
ft/lbs accordingly to which gear the tranny is in
That ft/lb of torque then goes to the drive shaft (am leaving out 4x4 here) to
go to the diff
At the diff (a transmission) there is another gear ratio and will normally
increase that ft/lb torque by the ratio number
That then goes to the axle shafts, that turn the wheel, that turns the tires
to finally put that ft/lb torque to pavement
Example:
100 ft/lb to tranny in first gear ratio of 6:1. Meaning the tranny output shaft
will have 600 ft/lbs to the drive shaft
100 ft/lb to the tranny in OD gear ratio of 0.7:1. Meaning the tranny output
shaft will have 70 ft/lbs to the drive shaft
The drive shaft is connected to the input shaft of the diff. Above 600 ft/lbs
in 1st gear will have the diff ratio multiply it to the axles
If a 4.1 diff ratio, that 600 ft/lbs will be 2,460 ft/lbs to the axle shafts
If a 3.73 diff ratio, that 600 ft/lbs will be 2,238 ft/lbs.
Notice that most all diff ratios are about 10% steps going up or down from each
other
The main reason why diesel's can have lower diff ratios, as they have very high
ft/lbs at low RPMs
Why gassers need higher ratios (not just at the diff, but also at today's close
ratio trannies) and spin faster to attain similar ft/lbs
Then there the various other diesel's and gassers...that has big block
gassers not able/designed to run at high RPMs.
My 7.4L gasser has a red line starting with dashed red at around 3.8K RPM
and would blow up above that & where small blocks can run all day at
Since more and more folks do not or did not go through that during
their boy racer/gear head/wrench teen days...the OEM's have removed
the human decision(s) to manage the RPMs of ICE's to the computers,
which are then highly integrated to other computers and systems
Like the automatic, ABS, traction control, torque control, etc, etc, etc
So and again...wonder why folks need to be worried about this. You all
(most) have driven the OEMs to take that decision away from you and
left it all to the computer
If watching the RPMs and controlling it for whatever driving condition
is that important...then order a manual the next time you purchase a TV...
HP, Horse Power, is what work that torque can do. Components are torque, RPM and
a simple algebraic formula: HP = torque x RPM / 5252 (torque multiplied by RPM
divided by 5252
A transmission multiplies or changes the input RPM to whatever ratio to the
output. Can be higher or lower depending on the ratio
So if the ICE develops, say 100 ft/lbs at the flywheel...it can have more or less
ft/lbs accordingly to which gear the tranny is in
That ft/lb of torque then goes to the drive shaft (am leaving out 4x4 here) to
go to the diff
At the diff (a transmission) there is another gear ratio and will normally
increase that ft/lb torque by the ratio number
That then goes to the axle shafts, that turn the wheel, that turns the tires
to finally put that ft/lb torque to pavement
Example:
100 ft/lb to tranny in first gear ratio of 6:1. Meaning the tranny output shaft
will have 600 ft/lbs to the drive shaft
100 ft/lb to the tranny in OD gear ratio of 0.7:1. Meaning the tranny output
shaft will have 70 ft/lbs to the drive shaft
The drive shaft is connected to the input shaft of the diff. Above 600 ft/lbs
in 1st gear will have the diff ratio multiply it to the axles
If a 4.1 diff ratio, that 600 ft/lbs will be 2,460 ft/lbs to the axle shafts
If a 3.73 diff ratio, that 600 ft/lbs will be 2,238 ft/lbs.
Notice that most all diff ratios are about 10% steps going up or down from each
other
The main reason why diesel's can have lower diff ratios, as they have very high
ft/lbs at low RPMs
Why gassers need higher ratios (not just at the diff, but also at today's close
ratio trannies) and spin faster to attain similar ft/lbs
Then there the various other diesel's and gassers...that has big block
gassers not able/designed to run at high RPMs.
My 7.4L gasser has a red line starting with dashed red at around 3.8K RPM
and would blow up above that & where small blocks can run all day at
Since more and more folks do not or did not go through that during
their boy racer/gear head/wrench teen days...the OEM's have removed
the human decision(s) to manage the RPMs of ICE's to the computers,
which are then highly integrated to other computers and systems
Like the automatic, ABS, traction control, torque control, etc, etc, etc
So and again...wonder why folks need to be worried about this. You all
(most) have driven the OEMs to take that decision away from you and
left it all to the computer
If watching the RPMs and controlling it for whatever driving condition
is that important...then order a manual the next time you purchase a TV...
