HP vs Torques for dummies like me

[noteven]

The green machine demonstrates HP

The rusty machine demonstrates torques

Clicky

[BenK]

Yup and the one hooked up 'higher' also has a better chance at that
kind of butt to butt tug-a-war...

Lost twice in my life time...both times in the mid 70's with my 73 K5
in my sig

First time at the secret place in the Idaho Panhandle. An old, old
guy drove up after we had setup camp. Getting ready to grill our
steaks...he must have been one of the care takers...after my BiL said
he was dating Simplots granddaughter...he relaxed and made that bet

An even older than him Green Powerwagon...but he put his draw bar
upside down with the ball up..thought he was a bit off... He advised me to
let off the gas if it started bouncing...thought what an arrogant
thing to say before we started...he let me spin my tires a bit then
pulled me where ever he wanted...he did enjoy that T-Bone...

A couple years later at Pismo...another Green Powerwagon made the
same bet after we setup and started cooking our clams, corn and
steaks...he was almost as old as the first Powerwagon guy...and
he too had his drawbar turned upside down

After losing to him both the tug-a-war and the steak...he laughed
while telling us 20 year olds that the one with the higher connection
point will lift the other guy's rear end and place more weight on
his...this to a young 26 years engineer thinking he knew EVERYTHING.... :S

rjstractor wrote:
Like others said it's all about tractive force in a tug of war. I used to have a little diesel 4WD tractor with just 15 hp. Someone with a 24 hp gas lawn tractor challenged me to a tug of war. I told him he didn't stand a chance due to him having much less weight and traction. He insisted, so we hooked up and went. I stood on the brakes and let his tires spin for a few seconds. I then put it in low gear, let out the clutch, advanced the throttle to about 1200 rpm and then very slowly proceeded to drag him across the gravel parking lot, the whole time my tractor's engine producing maybe 6 or 7 hp.

[copeland343]

https://www.edmunds.com/car-technology/the-twist-on-torque.html

[rjstractor]

Like others said it's all about tractive force in a tug of war. I used to have a little diesel 4WD tractor with just 15 hp. Someone with a 24 hp gas lawn tractor challenged me to a tug of war. I told him he didn't stand a chance due to him having much less weight and traction. He insisted, so we hooked up and went. I stood on the brakes and let his tires spin for a few seconds. I then put it in low gear, let out the clutch, advanced the throttle to about 1200 rpm and then very slowly proceeded to drag him across the gravel parking lot, the whole time my tractor's engine producing maybe 6 or 7 hp.

[wilber1]

4x4ord wrote:
I like to think of torque as the amount of fuel an engine can burn per revolution.

Horsepower is the amount of fuel an engine can burn per unit of time.

That's not bad. I like that.

[BenK]

I've over heard engineers on my staff argue over this...

Torque is the twisting force on a shaft...say drive shaft for this discussion

HP is the work that drive shaft does...or...work it can do

When the drive shaft has 1,000,000 ft/lbs of torque on it and the drive shaft
does *NOT* turn...there is *NO* HP...

Once it turns, whether a fraction of a turn or whole turns...there is HP being
developed

Because the formula for HP is:

HP = torque x RPM divided by 5252

And shows the relationship between torque and HP...why there can be tons
of torque and no HP if that shaft does NOT turn...

Guess which engineer was my fav and which I transferred to another
design team... :B

PS...guess which was the one inherited and which I had hired... :C

They were designing wind-generator gear boxes...main input shaft
was IIRC ~8 inches in dia...and the output shaft about 16 inches
in dia...made from heat treated 4160 and Timken's dia around 20" or so...

[RCMAN46]

VernDiesel wrote:
I got one you might like;

Torque is how much work it can do at a given rpm
Horsepower is how fast it can do that work at that rpm

It a simple way to help non motor heads understand the relationship between HP & TQ.

As soon as you tie rpm to torque you have defined horsepower.

Torque in it self does not define work. But horsepower does define work.

[VernDiesel]

I got one you might like;

Torque is how much work it can do at a given rpm
Horsepower is how fast it can do that work at that rpm

It a simple way to help non motor heads understand the relationship between HP & TQ.

[4x4ord]

Turtle n Peeps wrote:

Dave H M wrote:
Well so much for those mean looking pickups with the shag nasty looking tires on them. :W

The second set of pulls was really an eye opener for me.

And only 2 horsepower to boot! :B

You mean only two horses to shoe.

[Turtle_n_Peeps]

Dave H M wrote:
Well so much for those mean looking pickups with the shag nasty looking tires on them. :W

The second set of pulls was really an eye opener for me.

And only 2 horsepower to boot! :B

[srt20]

Dennis M M wrote:
In the sports car racing world the explanation is:

horsepower determines how FAST you hit the wall,

torque determines how HARD you hit the wall!

In the circle track world its:

HP is how fast you hit the wall

TQ is how far you take the wall with you...

[Dave_H_M]

Well so much for those mean looking pickups with the shag nasty looking tires on them. :W

The second set of pulls was really an eye opener for me.

[Turtle_n_Peeps]

That demonstrates neither.

As Trans said, this whole video demonstrates traction. Hook the steamer to a 4' tree stump and try to pull it out of the ground. Does the tree stump have more torque by not going anywhere? No, it has more traction to stay put and be anchored into the ground.

Talk to any puller or drag racer and the holy grail is traction and with the weight of the steamer, it had a LOT of traction.

Look at the 5 minute mark. You think the pickup wins because he has more torque? No, he wins because he has more traction.

Horses, with their small foot print have a lot of traction too!

[boshog]

Torque is the amount of twist that is applied, horsepower is how fast the torque is applied.

[4x4ord]

I like to think of torque as the amount of fuel an engine can burn per revolution.

Horsepower is the amount of fuel an engine can burn per unit of time.