help me understand torque and hp

[randay]

I like square engines. 700 hp AND 700 lb-ft torque from 2000 RPM to redline.

Why pick just one?

so 2000 rpm redline then...

... man there is so much wrong with this thread.

 

[randay]

Running full torque all the time? I think those are called trucks. No they don't fail every couple miles.

only an electric truck.

 

[arcenite]

so 2000 rpm redline then...

... man there is so much wrong with this thread.

You missed a word there. 2000 TO redline.

What's wrong with this thread is the armchair mechanics. WTF is "full torque"?. And no shit a "civic engine" doesn't have the same torque as a "truck engine". It's called: displacement.

Shawn, go away.

 

[Throckmorton]

People are making it too complicated.

Torque is the rotational force of the engine.

Horsepower is a product of that rotational force and rotation speed.

Forget about the peak values and equations and all that stuff that just makes it harder to understand the basic principles.

If one engine is spinning at 3000rpm making 200ftlb, and another is spinning at 6000rpm making the same 200ftlb, the faster spinning one is putting out twice the horsepower.

 

[randay]

You missed a word there. 2000 TO redline.

What's wrong with this thread is the armchair mechanics. WTF is "full torque"?. And no shit a "civic engine" doesn't have the same torque as a "truck engine". It's called: displacement.

Shawn, go away.

no i didnt miss the word, but i may have comprehended his sentence wrong. depends if he wants 700HP AND 700 torque. or if he meant he just wants torque from 2000 to redline.

 

[arcenite]

no i didnt miss the word, but i may have comprehended his sentence wrong. depends if he wants 700HP AND 700 torque. or if he meant he just wants torque from 2000 to redline.

My guess is exdeath was just yet again bragging about his amazingly flat torque curve. It makes him feel better than all of us, so just let him be.

 

[MotF Bane]

I like square engines. 700 hp AND 700 lb-ft torque from 2000 RPM to redline.

Why pick just one?

My goodness that'd be nice. You'd need rotating slabs of superglue to keep it under control.

 

[exdeath]

My guess is exdeath was just yet again bragging about his amazingly flat torque curve. It makes him feel better than all of us, so just let him be.

Just making a point that you can have both. Every time this discussion comes up, everyone makes out like you are forced to pick one or the other. Build an engine that does both and stop worrying about it.

Is like stupid racing games where you have bars that show a cars abilities and have to make trade offs. Like best top speed invariably has the worst acceleration, etc Screw that, build a car that has all the bars maxed at the same time.

 

[punjabiplaya]

People are making it too complicated.

Torque is the rotational force of the engine.

Horsepower is a product of that rotational force and rotation speed.

best example would be an electric motor:

maximum torque @ 0 rpm and pretty much linear until you reach the upper limits of the motor

then horsepower becomes a function of rpm

 

[futuristicmonkey]

so 2000 rpm redline then...

... man there is so much wrong with this thread.

No kidding!

Just wait till someone tells them that you actually control torque via the throttle and its actually the drivetrain friction + wind resistance + gravity (if traveling up a slope) that determines the output speed, and therefore the HP, of the engine.

Torque is the important quantity.

 

[Howard]

It's easier if you forget about the transmission. The amount of torque is usually proportional to the rate at which you accelerate a body (usually rotationally).

 

[DominionSeraph]

Just making a point that you can have both.

No, you can't. Torque x Engine speed / 5,252 = Horsepower. If your torque is flat your horsepower goes through the roof at high RPM's. You cannot have them both being the same as RPM goes up.

What you said nearly the same as saying, "I want it to take me an hour to go 60 miles all the way up to 200MPH."

700lb-ft of torque would be:
133HP at 1000RPM
266HP at 2000RPM
399HP at 3000RPM
533HP at 4000RPM
666HP at 5000RPM
700HP at 5252RPM <--- where HP and Torque cross
799HP at 6000RPM

This is why saying, "700lb-ft and 700HP from 2000RPM to redline," is retarded. If you have 700lb-ft you do not have 700HP at 2000RPM, 3000RPM, or anywhere else but 5252RPM.

 

[Elfear]

We already had this argument in the thread where I said diesel was the worst thing ever.

Aww. They're not that bad. 148mph & 38mpg sounds pretty good to me.

 

[exdeath]

No, you can't. Torque x Engine speed / 5,252 = Horsepower. If your torque is flat your horsepower goes through the roof at high RPM's. You cannot have them both being the same as RPM goes up.

What you said nearly the same as saying, "I want it to take me an hour to go 60 miles all the way up to 200MPH."

700lb-ft of torque would be:
133HP at 1000RPM
266HP at 2000RPM
399HP at 3000RPM
533HP at 4000RPM
666HP at 5000RPM
700HP at 5252RPM <--- where HP and Torque cross
799HP at 6000RPM

This is why saying, "700lb-ft and 700HP from 2000RPM to redline," is retarded. If you have 700lb-ft you do not have 700HP at 2000RPM, 3000RPM, or anywhere else but 5252RPM.

That's pretty obvious genius. I didn't say both at the same time, also notice emphasis on AND to establish word grouping:

700 hp AND 700 lb-ft torque from 2000 RPM to redline.

It's understood that most people in ATG are not dumbasses, know what a typical dyno sheet looks like (flat torque and climbing HP) and wouldn't mistake that for 700 HP at 2000 RPM. Only you.

Yes this does mean you can have an engine that puts out both low end torque and high horsepower. Most think you either get lots of torque but no revving or high end HP (diesel, old muscle cars, etc), or high revving high HP and no off the line grunt (M3, S2K, etc). You can have both, something that both lifts the front wheels off the ground off the line AND continues pulling like train at 7K+ RPM.

 

[darkswordsman17]

HP=how fast you punch
TQ=how hard you puch

Martin Brundle said that.

Yeah, the easiest way of thinking about this is, torque is the force, and horsepower is how quickly that force is applied.

 

[randay]

My guess is exdeath was just yet again bragging about his amazingly flat torque curve. It makes him feel better than all of us, so just let him be.

ah youre right....

back to the OP, to try and put it in a less technical way, you can think of torque as a baseline measurement of the engines power, and horsepower as an indication of how that torque is put to use.

so all other things being equal, you could say 50 torque, 100 hp = econobox. 100/150 = sports car, 150/100 = dump truck. But you dont necessarily want 700 torque and 700 horsepower... For example, an f1 engine has a measly 200 torque, but 800 hp.

 

[bommy261]

torque is similar to how much force is generated inside the engine after ignition per cycle.

horse power is similar to the summing of the torque forces per second.

for instance, a crotch rocket 600cc motorcycle. while they do not have alot of torque generated per ignition cycle due to their small displacement, they make up for the fact that this ignition cycle happens 12k rpms allowing for high horse power.

a diesel engine on the other hand generates huge torque values due to its high compression during ignition. however this does not happen that often rpm wise so it has less horse power

torque is how much force*distance is being applied to the crankshaft during ignition.

horse power is using those torque values over time to figure how much work is being done.

torque and horse power are related somewhat.. but the concept behind them is different

 

[DominionSeraph]

That's pretty obvious genius. I didn't say both at the same time, also notice emphasis on AND to establish word grouping:

700 hp AND 700 lb-ft torque from 2000 RPM to redline.

Poor phrasing on your part as you did not properly isolate from the prep phrase.

"700 peak horsepower along with 700lb-ft from 2000RPM to redline." would've been better, which puts your redline at 5252RPM.

It's understood that most people in ATG are not dumbasses,

"No one ever went broke underestimating the intelligence of the American public."

Yes this does mean you can have an engine that puts out both low end torque and high horsepower. Most think you either get lots of torque but no revving or high end HP (diesel, old muscle cars, etc), or high revving high HP and no off the line grunt (M3, S2K, etc). You can have both, something that both lifts the front wheels off the ground off the line AND continues pulling like train at 7K+ RPM.

No news to we Bandit 1200 owners.

 

[Bartman39]

"No one ever went broke underestimating the intelligence of the American public."

Now I realize your not just an idiot... Got some antagonistic azzhole-izum built in too... (yea I provoke when I see stupid crap, almost like another bozo with his trailer towing Corolla):hmm:


Dont screw with exdeath he could pull 3 plug wires off his Stang and still "torque twist" your little rice ride in to Saki... I could use it for fuel system cleaner for my 398HP/760ftlb little diesel truck...


In the real world to put it simple a light car works good with high HP and moderate torque with proper gearing and an efficient transmission standard or auto... Likewise a heavy truck can also be quick but it requires high torque to move its mass but needs the HP to make this happen quickly... Also turbo`s and superchargers make engines much more efficient with both HP and TQ and with advances in electronic controls on them the flat power curves can be accomplished... Just a hint... Look up the term VVT with respect to turbo tech...

 

[IcePickFreak]

Poor phrasing on your part as you did not properly isolate from the prep phrase.

"700 peak horsepower along with 700lb-ft from 2000RPM to redline." would've been better, which puts your redline at 5252RPM.

"No one ever went broke underestimating the intelligence of the American public."

No news to we Bandit 1200 owners.

I think you need to stick to your pony thread, what he said was pretty clear to anyone not trolling.

 

[Viperoni]

The amount of torque is usually proportional to the rate at which you accelerate a body (usually rotationally).

You can think of torque as a baseline measurement of the engines power, and horsepower as an indication of how that torque is put to use.

Finally somebody said it.

Torque is what actually accelerates a car, and your acceleration can be determined by how much torque the motor is putting out.

Horsepower is a measurement of how much torque there is to accelerate a car at a particular rpm. This is because HP is calculated from torque.


When I look at dyno graphs I dont look at HP curves at all because the torque curve tells you everything you need to know, and as stated by Howard, is the rate at which you will be accelerating.

 

[DrPizza]

Let's say that you can lift 10 kilgrams 5 meters in 2 seconds. Your average power output is approximately 250 watts.

And, let's say that someone else can lift 20 kilograms 2.5 meters in 2 seconds. Their average power output is also 250 watts.

The amount of power needed to lift 1000 kilograms 5 centimeters in 2 seconds is also 250 watts. But, while I'm capable of generating well over 250 watts of power, I'm not capable of lifting 1000 kilograms 5 centimeters in 2 seconds.... I can't generate enough torque.

(Not a perfect explanation, and I didn't put much thought into the math, so there might be a careless mistake; the point is the same though, and I used 10m/s&#178; for g, not 9.8.)

 

[OS]

best example would be an electric motor:

maximum torque @ 0 rpm and pretty much linear until you reach the upper limits of the motor

then horsepower becomes a function of rpm

I don't believe every electric motor behaves like that, the torque/power output depends on the motor type
just saying

 

[punjabiplaya]

I don't believe every electric motor behaves like that, the torque/power output depends on the motor type
just saying

it doesn't, I was using it to explain what effect rpm has on torque and hp.

 

[Throckmorton]

Finally somebody said it.

Torque is what actually accelerates a car, and your acceleration can be determined by how much torque the motor is putting out.

Horsepower is a measurement of how much torque there is to accelerate a car at a particular rpm. This is because HP is calculated from torque.


When I look at dyno graphs I dont look at HP curves at all because the torque curve tells you everything you need to know, and as stated by Howard, is the rate at which you will be accelerating.

Not true. The torque at the wheels is what accelerates the car. If the engine makes the same horsepower at higher RPM with less torque, gear it shorter, and the car doesn't know the difference.

You can put a truck diesel engine with 1000ftlb in a car, but the low RPM makes it necessary to gear it up so the car doesn't accelerate any faster than a lower torque gas engine.