POLL: Is Torque Important?

[Sled Puller]

Pretty good discussin in another thread, but it was hijacked.

 

[fox]

Nothing else compares! The 'Girley Guys' over at the other poll just don't understand.

 

[klenger]

I am going to be in the minority on this one. I personally believe that all the discussion about diesel torque misses the point to a degree. HP is everything. What makes a diesel like the Cummins work so well is that it developes it's HP much earilier in the RPM range because it creates so much low end torque, but it's the HP that, in the end, gets the work done. There is an online calculator that calculates the power required to move a loaded truck and trailer under various conditions. You input weights, frontal area, grade and speed. The calculator outputs the HP needed to operate under those conditions. The HP can come from any source, diesel, gas, electric, or steam, but in the end, it's HP that gets the job done. Again, what makes the Cummins so great is that it developes HP at low RPM's because it can develope torque at low RPM's. Flame on.

 

[fox]

Just for some more thought- can you tell me why I can go to Sears and buy a Torque Wrench, but cannot buy a Horsepower wrench?

 

[rbattelle]

To me, Hp is just an expression of rate of work output. Torque is actually work output (notice torque and work have the same units). Who cares how fast you can work if your maximum work output won't pull a bicycle down the street? I've always said, if I could change my engine to get 250 hp and 800 lb-ft I'd do it.



Klenger - be careful... your engine doesn't make peak Hp until 2900 RPM... too late to be of any real use, IMHO!



-Ryan



On edit:

I just thought of an analogy. Let's say as a human you had a TON of Hp but no torque capacity (work). And let's say you had 500 lb of earth to move from 1 pit to another. Well, your only choice would be to run really fast (since you've got lots of Hp) between each pit with a little shovel (since you have little torque) and move the dirt that way. If, on the other hand, you had no Hp and tons of torque capacity (work), you'd just move the entire 500 lb of dirt in 1 slow trip. That's how I think of it. Am I wrong?

 

[sfr1047]

Clydesdales and Shetlands

Clydesdales and Shetlands are both horses but one has alot more torque.

A Dodge Ram and a Honda both may have 300 HP but put them on a hill with 15,000# in tow and see which one continues up.

 

[GIT-R-DONE]

Why is it that my Cummins makes 274 HP and 687 TQ and a friend of mine makes 380 HP and only 700 TQ (Ford). Lets see, he make approx 105 more HP but has equal torque? OH, these numbers are off the same dyno BTW. I dont understand that...

 

[rbattelle]

Why is it that my Cummins makes 274 HP and 687 TQ and a friend of mine makes 380 HP and only 700 TQ (Ford). Lets see, he make approx 105 more HP but has equal torque? OH, these numbers are off the same dyno BTW. I dont understand that...

You can both do the same amount of work, but he can do it a lot faster than you.

 

[GIT-R-DONE]

You can both do the same amount of work, but he can do it a lot faster than you.

Well, if thats the case a friend of mine with his Duramax makes 245 horse and only 410 TQ ( yes, same dyno) and I walk all over him at will, towing, but yet we are very close to the same HP. Whats up with that?

 

[Wiredawg]

My twist

About 100 years ago, a physics teacher I had used this simple explantaion: torque is the force used to get a load moving and horse power is a force that keeps it moving. Both are important: Torque to get it rolling and HP to move it down the road.



Wiredawg

 

[rbattelle]

Well, if thats the case a friend of mine with his Duramax makes 245 horse and only 410 TQ ( yes, same dyno) and I walk all over him at will, towing, but yet we are very close to the same HP. Whats up with that?

In that example, you can both work at about the same rate but you're capable of doign a lot more work than him. So if you're both pulling 12k he's at his maximum work load and you're just barely breathing, leaving you room to move faster.

 

[Sled Puller]

About 100 years ago, a physics teacher I had used this simple explantaion: torque is the force used to get a load moving and horse power is a force that keeps it moving. Both are important: Torque to get it rolling and HP to move it down the road.



Wiredawg

WD,

I said almost that very thing on another thread, and was told in no uncertain terms, torque is NOT a force.

 

[rbattelle]

WD,

torque is NOT a force.

That is absolutely true: torque is not a force. Torque is a force applied across an arm, also known as a moment.

 

[GIT-R-DONE]

Well, the only real thing I know to be true is " I LOVE MY TRUCK "



The Torque / Horespower issue I may never really understand because of different things in life that I have seen/experienced. It is weird that some say horsepower is where its at while others think (like myself) that torque is a good thing but is not a direct result of how much horsepower you have. By watching too many dyno runs, thats proven to me that the amount of horsepower you have does not determine what torque you make.



If "x" amount of horsepower made "x" amount of torque and it was all the same no matter what you were driving, then it would be true that the horsepower is the direct source of torque, ie: the above example of the 300 horse honda pulling a 15 K load, aint gonna happen.



Sleddy, what other thread was discussing this? Didnt find it.





rbattelle said:

To me, Hp is just an expression of rate of work output. Torque is actually work output (notice torque and work have the same units). Who cares how fast you can work if your maximum work output won't pull a bicycle down the street? I've always said, if I could change my engine to get 250 hp and 800 lb-ft I'd do it.



I dont know about you guys but I can really feel torque, but its harder to feel HP. I too would like a 300 horse 1000 ft lb truck, I am getting there, slowly...

 

[smokejunkie]

Torque Is Horsepower

 

[Sled Puller]

GIT:

https://www.turbodieselregister.com/forums/showthread.php?t=101272&goto=newpost

 

[Mad Bomber]

Got torque

Just for some more thought- can you tell me why I can go to Sears and buy a Torque Wrench, but cannot buy a Horsepower wrench?

I belive it's a VERY big part :-laf

 

[Sled Puller]

Again, what makes the Cummins so great is that it developes HP at low RPM's because it can develope torque at low RPM's. Flame on.

Klenger, reread that again.

 

[Cummins4Life]

Did the good Doctor get the boot or is he just not participating?



I always thought Wiredawg's explanation sumed it up nicely.

 

[klenger]

Klenger, reread that again.

<b>I don't need to reread it... I wrote it and I stand by it. </b> I never said that torque was not important. In fact it is one of the three ingrediants of the HP formula, the other two being RPM and a constant.



As to my needing to run my engine at 2900 RPM to get max HP, well DUH. If torque is more imprtant than HP then let's see our fellow members pull 20,000 lbs up a 15 mile 7% grade at 60 MPH at 1600 RPM, which is where the Cummins 600 reaches max torque.



Looking at it another way, if you are traveling at 1600 RPM at max torque, why does the truck go faster when you add more fuel? Could it be,... . drum roll here... more HP as RPMs increase.