Is Torque King?

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273

273

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I keep seeing people give misguided advise base on don't build engine A cause engine B will make more torque eg. . 340 vs 360 or 360 vs 408. For the most part torque is a useless number once HP curve is found from it.

There is a lot of reason to build HP at low rpm (torque engine) instead of high rpm thats why the factory kept going with larger engines over high rpm ones but a 400 hp engine is a 400 hp engine no matter if it's build with lots of torque at a low rpm or little torque at an high rpm both can do the same amount of work in the same amount of time eg... Accelerate your car (weight) in a certain amount of time ( E.T. ).

I think the problem is its easy for us to see HP and Torque as units of power or potential power but not RPM. But if you look at it like *this you want to move a 1000 tons of dirt a hundred miles away. And there's two trucks to do it (500 tons each) and one can move a 100 tons at 50 mph and the second truck can move 50 tons at a 100 mph. Both will move 500 tons in the same amount of time of 20 hrs but one will take 5 trips and the other 10 trips but both will do the same job. Trucks=engines......... Tons = torque....... Mph = rpm.........both are needed in some ratio to do the job moving 1000 tons a 100 miles in a certain amount of time 20hrs = Horsepower.

So when people ask about 318 vs 340/360, 340 vs 360 etc... Tell about gearing, stall speed, drive ability etc... Instead of 360 will make 30 lbs ft more than a 340 so a 340 is always doomed to lose cause it isn't true that's why they invent different gear ratios. And the main reason I wrote this a guy with a mild 360 wanted to know if his next step should be invest his money in the top end (heads) or bottom end (408 ) for more power and almost everyone agreed with the 408 and stock J heads instead of 360 and eddy rpm heads like it's magically gonna make more Power because it's larger.
 
273 said:
I keep seeing people give misguided advise base on don't build engine A cause engine B will make more torque eg. . 340 vs 360 or 360 vs 408. For the most part torque is a useless number once HP curve is found from it.

There is a lot of reason to build HP at low rpm (torque engine) instead of high rpm thats why the factory kept going with larger engines over high rpm ones but a 400 hp engine is a 400 hp engine no matter if it's build with lots of torque at a low rpm or little torque at an high rpm both can do the same amount of work in the same amount of time eg... Accelerate your car (weight) in a certain amount of time ( E.T. ).

I think the problem is its easy for us to see HP and Torque as units of power or potential power but not RPM. But if you look at it like *this you want to move a 1000 tons of dirt a hundred miles away. And there's two trucks to do it (500 tons each) and one can move a 100 tons at 50 mph and the second truck can move 50 tons at a 100 mph. Both will move 500 tons in the same amount of time of 20 hrs but one will take 5 trips and the other 10 trips but both will do the same job. Trucks=engines......... Tons = torque....... Mph = rpm.........both are needed in some ratio to do the job moving 1000 tons a 100 miles in a certain amount of time 20hrs = Horsepower.

So when people ask about 318 vs 340/360, 340 vs 360 etc... Tell about gearing, stall speed, drive ability etc... Instead of 360 will make 30 lbs ft more than a 340 so a 340 is always doomed to lose cause it isn't true that's why they invent different gear ratios. And the main reason I wrote this a guy with a mild 360 wanted to know if his next step should be invest his money in the top end (heads) or bottom end (408 ) for more power and almost everyone agreed with the 408 and stock J heads instead of 360 and eddy rpm heads like it's magically gonna make more Power because it's larger.[/QUOT
I always looked at the budget,what equipment I have to work with/buy, & what I want it to do. For instance,my Scamp has 3:55's out back & a 727/3200 honest rated converter.(I built the Magnum,to work with those). What you're saying,makes complete sense. Why build a 408 & feed it with 210 c.f.m. heads? I believe a lot of that ,comes with a eye towards street drive able(less gear & converter needed usually) & the "bigger is better" theory. My nickel.....
Click to expand...
 
"Is torque king?" I think for a street car, yes. Torque and horse power are the same thing read differently. They are both measurements of exerted force. I would much rather have a higher torque lower horse power engine for the street than the other way around.
 
From what I understand, torque can be multiplied like thru a trans, but horsepower can not.
 
spl440 said:
From what I understand, torque can be multiplied like thru a trans, but horsepower can not.
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Thats why two engines with the same HP have the same potential eg.. 1/4 mile time even if one engine has 300 lbs ft vs one with 600 lbs ft the one with half the torque would require twice as deep gear set eg... 300 X 6:1=1800
600 X 3:1=1800 both are having the 1800 lbs ft going to the tires.
 
273 said:
Thats why two engines with the same HP have the same potential eg.. 1/4 mile time even if one engine has 300 lbs ft vs one with 600 lbs ft the one with half the torque would require twice as deep gear set eg... 300 X 6:1=1800
600 X 3:1=1800 both are having the 1800 lbs ft going to the tires.
Click to expand...


I respectfully disagree. Your concept (and initial statements starting the thread) only make some sense if you remove all the other variables that make up a complete car and elapsing time. you're applying a snapshot in terms of power and acceleration rate to the movie that really represents them both. The power curves and more importantly the application of that power are not linear, so the performance potential, or more precisely the time required to realize that potential is not identical.
 
I have seen quite a few motors that don't cross hp and tq at 5252 rpm??
Though usually a race motor, but I've always heard they cross.
 
I think another thing that needs to be considered is the width of the torque curve. High horsepower isn't very useful if it is a very steep & sharp curve(peak) that only last for a few RPM. A broader torque curve will accelerate a car better throughout the whole run. HP #s are more about bragging rights. Torque is what accelerates the car.
 
Its about area under curve, and where in that curve your transmission/gearing keeps you.

for example new car with about 150hp can beat 300hp muscle car, even if muscle car has way more torque.
Why because of gearing and trans keeps that 150hp on tires right from start.

other simple example.
I had 50cc dirt bike at kid, we tuned it and it would rew 18000rpm. that thing was fast even when 0-14000rpm was useless, it made all power 14000-18000rpm.
But with good clutch operating i could keep that thing on that power curve.


But anyways torque is more fun on street car, makes tires go away :)
 
Lonewolf3165 said:
I think another thing that needs to be considered is the width of the torque curve. High horsepower isn't very useful if it is a very steep & sharp curve(peak) that only last for a few RPM. A broader torque curve will accelerate a car better throughout the whole run. HP #s are more about bragging rights. Torque is what accelerates the car.
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lonewolf is right on this one! take your 400 horse 300 ft lbs of torque small block and put it in a 3800 lb car, then take a 500" big block and put it in that same car, changing nothing else, with equal traction, and see which one gets to the end of an 1/8 mile first.-been there done that---bob
 
Horsepower is the ability to do work over time.


Torque is how much force that it can exert.
 
krazykuda said:
Horsepower is the ability to do work over time.


Torque is how much force that it can exert.
Click to expand...


That is absolutely correct, and HP is quite simply a mathamatical representation of torque and time, simple, end of story.

If you don't want to believe that, simply look at what the dyno uses to GET those figures............what amounts to a load device, something to measure force, (torque) and a tachometer
 
I had typed up a whole response to this thread but after I read it I thought it sounded like I was bashing the author of the thread..
So in not so many words..I do this for a living,40 years..almost everyday in the summer I build and tune on perf cars..small blocks with 5.57 gears big blocks with no gear, all kinds.
If you have a street car..you want TQ..!!
At the drag strip you can use 7.17's if you need tq.
Just my take on it..
 
At least for me - torque is the king. Torque is what is best when the engine is in a compromise vehicle. Like a street car, or a street/strip car, or a street/road racing car. The reason most curves cross at 5200 or so is a combination of the mathematical formual that calculates horsepower from torque and it's constant, and the way a dyno calculates. The reason not every engine does that is differences in local dyno calibration, data sampling rates, and the software that crunches the numbers.
 
Diesel trucks with low HP and high Torque are
winning at the strip on a daily basis.
Give me torque over hp any day.
 
Torque is king, a motor that makes 400 ft-lbs at 3000 rpm accelerates a car exactly the same as 400 ft-lbs at 6000 rpm even though the second is making twice the horsepower. So twice the horsepower but exactly the same force. Where the high HP is effective is if you make the torque early and hold it to those high rpms. But if you are just going to make 400 ft-lbs from say 2000-4000 or 4000-6000 they will perform the same even though one motor has much higher hp. So you are right you could put a ton of gear in the big hp motor and then drive around at 4000 rpm getting 3 mpg.
 
Hersbird said:
Torque is king, a motor that makes 400 ft-lbs at 3000 rpm accelerates a car exactly the same as 400 ft-lbs at 6000 rpm even though the second is making twice the horsepower. .
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No, it's not. "The Same Thing." Some of you guys need to get to the basics of what torque and HP IS

Torque IS HP and HP IS torque. HP is simply a mathematical representation of torque and time. PERIOD

The two are not disconnected from each other
 
67Dart273 said:
That is absolutely correct, and HP is quite simply a mathamatical representation of torque and time, simple, end of story.

If you don't want to believe that, simply look at what the dyno uses to GET those figures............what amounts to a load device, something to measure force, (torque) and a tachometer
Click to expand...



Our high school physics teacher had us measure our own horsepower.

We ran up and down a set of stairs (you have to work against gravity) and he timed how long it took. We then converted the time it took with our weight to calculate our horsepower.

So basically, if you were the same weight, the faster you could run the stairs, the more horsepower that you "put out"...


I guess another way to look at it is:

Torque is how much strength you have (how much weight you can lift).

Horsepower is how fast you can move it.


You can be weaker than someone else, but if you can climb the stairs faster (per pound that you weigh) than the other guy, you have more horsepower. That is the difference between horsepower and torque. Torque is strength, horsepower is how fast you can move the weight.


You need more torque to get a heavier mass moving. Your ability to make it move is horsepower. That is why a heavier car needs more torque to get it moving.
 
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