Why does torque decrease as RPM increase?
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3rd Gear
Joined: Dec 2002
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From: San Francisco
Why does torque decrease as RPM increase?
Hi Everyone - wondering if someone can give me a hand... I'm one of those guys who can drive a car, but lift the hood and say "yep... that's an engine allright..."
Why does torque decrease as RPM increases? Does it have to do with volumetric efficiency or decreasing Mechanical Efficiency?
Happy holidays, all.
Why does torque decrease as RPM increases? Does it have to do with volumetric efficiency or decreasing Mechanical Efficiency?
Happy holidays, all.
Racer
Joined: Apr 2002
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From: Long Island, NY
[quote]Originally posted by Dave Thomas:
<strong>It doesn't always. Torque has a curve and horsepower has a curve. They both increase to the point that the curves cross.</strong><hr></blockquote>
Not exactly. The curves will always cross around 5200rpm (5252 to be exact). At that time either curve can be going up or down.
<strong>It doesn't always. Torque has a curve and horsepower has a curve. They both increase to the point that the curves cross.</strong><hr></blockquote>
Not exactly. The curves will always cross around 5200rpm (5252 to be exact). At that time either curve can be going up or down.
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Rennlist
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From: CT
[quote]Originally posted by Vinny '98 3.8 C2S:
<strong>
Not exactly. The curves will always cross around 5200rpm (5252 to be exact). </strong><hr></blockquote>
I've never noticed that - is it a function of physics/mechanics/math, or from the convention of how torque/hp are graphed?
<strong>
Not exactly. The curves will always cross around 5200rpm (5252 to be exact). </strong><hr></blockquote>
I've never noticed that - is it a function of physics/mechanics/math, or from the convention of how torque/hp are graphed?
Racer
Joined: Apr 2002
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From: Long Island, NY
[quote]Originally posted by Matt:
<strong>
I've never noticed that - is it a function of physics/mechanics/math, or from the convention of how torque/hp are graphed?</strong><hr></blockquote>
It's simply a function of the way Torque and HP are calculated. They are always directly related.
The formula for HP, as related to torque, is:
Horsepower = (Torque)(RPM)/5252
Therefore, at 5252 rpm:
HP = (Torque) 5252/5252 or HP = Torque times 1.
<strong>
I've never noticed that - is it a function of physics/mechanics/math, or from the convention of how torque/hp are graphed?</strong><hr></blockquote>
It's simply a function of the way Torque and HP are calculated. They are always directly related.
The formula for HP, as related to torque, is:
Horsepower = (Torque)(RPM)/5252
Therefore, at 5252 rpm:
HP = (Torque) 5252/5252 or HP = Torque times 1.
R.I.P.
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From: New London, NH & Naples
This might help.
<a href="http://www.howstuffworks.com/question622.htm" target="_blank">http://www.howstuffworks.com/question622.htm</a>
or start at <a href="http://www.howstuffworks.com" target="_blank">www.howstuffworks.com</a> and start witht he internal combustion engine. If nothing else it makes good reading.
<a href="http://www.howstuffworks.com/question622.htm" target="_blank">http://www.howstuffworks.com/question622.htm</a>
or start at <a href="http://www.howstuffworks.com" target="_blank">www.howstuffworks.com</a> and start witht he internal combustion engine. If nothing else it makes good reading.
