Maybe this is why our beasts run so well !
#1
01-20-2005, 07:49 AM
Maybe this is why our beasts run so well !
Was nosing around www.myford.fordvehicles.com and ran across this interesting tidbit that I "knew from seat of the pants" but hadn't verified ....
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Tough Talk: Understanding Torque versus Horsepower
Horsepower is the stuff legends are made of--think screeching tires and checkered flags--but unless you're a NASCAR driver, horsepower has little to do with your everyday driving experience. Fact is, torque should matter more to the real-world motorist.
Why is that? Horsepower is the measure of your engine's peak power output at a relatively high engine speed (RPMs or revolutions per minute). It dictates how fast your vehicle can go. Torque, however, measures your engine's efficiency at a lower RPM. Torque figures show how much actual work (accelerating, hauling, towing) your engine can do in normal operating conditions.
So what? Ford research shows that most motorists rarely reach the engine speed needed for peak output (about 5,000 RPMs). In fact, drivers usually operate their engines at less than 2,500 RPMs 95% of the time. Because of this, it's torque statistics--not horsepower--that are the best measure of your vehicle's power and efficiency.
First published on: 2004-06-01
*************************************
Tough Talk: Understanding Torque versus Horsepower
Horsepower is the stuff legends are made of--think screeching tires and checkered flags--but unless you're a NASCAR driver, horsepower has little to do with your everyday driving experience. Fact is, torque should matter more to the real-world motorist.
Why is that? Horsepower is the measure of your engine's peak power output at a relatively high engine speed (RPMs or revolutions per minute). It dictates how fast your vehicle can go. Torque, however, measures your engine's efficiency at a lower RPM. Torque figures show how much actual work (accelerating, hauling, towing) your engine can do in normal operating conditions.
So what? Ford research shows that most motorists rarely reach the engine speed needed for peak output (about 5,000 RPMs). In fact, drivers usually operate their engines at less than 2,500 RPMs 95% of the time. Because of this, it's torque statistics--not horsepower--that are the best measure of your vehicle's power and efficiency.
First published on: 2004-06-01
#2
01-20-2005, 08:50 AM
#4
01-20-2005, 10:09 AM
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Yeah torque is definately important. A big part of the 5.0L mustang legacy and the ability to get off the line quick. It makes me laugh all the little ricers who all do intake and exhaust mods and just destroyed their low end TQ. Now sure the motor runs great at 6000-7500 rpms, but by the time they get there they are already choking on PSD emissions.
Most modifications would be good for the track but are impractical for the street.
Most modifications would be good for the track but are impractical for the street.
#5
01-20-2005, 10:45 AM
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True, but not the whole story.
Yes torque is definitely what gives you the ability to accelerate - what gives you that feeling in the seat of your pants when you stomp the go pedel. But if a motor has great torque but runs out of it after a few thousand RPM you'd better have a transmission with a bunch of extra gears if you want to get any work done at a real rate.
Given two motors of nearly equal torque, you want to pick the one that is able to carry the torque out to the highest RPM. So if you had a Cummins that makes the same torque - or even a tad more - than a PSD, but it tops out at 2800 RPM or what ever their limit is, you'd want the PSD because it is able to rev on out to 3600 RPM in stock trim. It is those extra revs, even if at lower torque output, that let us out pull a Cummins up a grade with trailer in tow.
Torque down low is what makes the vehicle more driveable around town and when you're trying to move a trailer off the line. Being able to carry that torque out to the broadest RPM range (highest HP) is what lets you get a lot of work done.
HP is torque times RPM divided by a constant scaling factor.
Yes torque is definitely what gives you the ability to accelerate - what gives you that feeling in the seat of your pants when you stomp the go pedel. But if a motor has great torque but runs out of it after a few thousand RPM you'd better have a transmission with a bunch of extra gears if you want to get any work done at a real rate.
Given two motors of nearly equal torque, you want to pick the one that is able to carry the torque out to the highest RPM. So if you had a Cummins that makes the same torque - or even a tad more - than a PSD, but it tops out at 2800 RPM or what ever their limit is, you'd want the PSD because it is able to rev on out to 3600 RPM in stock trim. It is those extra revs, even if at lower torque output, that let us out pull a Cummins up a grade with trailer in tow.
Torque down low is what makes the vehicle more driveable around town and when you're trying to move a trailer off the line. Being able to carry that torque out to the broadest RPM range (highest HP) is what lets you get a lot of work done.
HP is torque times RPM divided by a constant scaling factor.
#6
01-20-2005, 09:15 PM
#7
01-20-2005, 09:22 PM
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Originally Posted by tn mac
DARYL guess you have never been to a truck pull, the cummins will out pull a psd every time and that is a fact. also the 6.0 is terrible getting the load moving, because of the turbo, which is why ford is scraping the vvt and going to twins in 07 no low end on the 6.0.
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#9
01-20-2005, 09:38 PM
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Originally Posted by Fastest1
I must be a Nascar driver then because I always drive with it wound up. Of course in Houston traffic I see people who must idle because they dont really want to get home at that pace! I guess I have more to come home to!
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01-20-2005, 09:39 PM
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Originally Posted by tn mac
DARYL guess you have never been to a truck pull, the cummins will out pull a psd every time and that is a fact. also the 6.0 is terrible getting the load moving, because of the turbo, which is why ford is scraping the vvt and going to twins in 07 no low end on the 6.0.
#11
01-20-2005, 09:42 PM
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Originally Posted by tn mac
DARYL guess you have never been to a truck pull, the cummins will out pull a psd every time and that is a fact. also the 6.0 is terrible getting the load moving, because of the turbo, which is why ford is scraping the vvt and going to twins in 07 no low end on the 6.0.
and twin turbos is the worst thing in the world of diesels for low end torque.
lets have a link to the twins.
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01-20-2005, 10:53 PM
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#14
01-21-2005, 08:18 AM
