Horsepower Vs. Torque
03-25-2006, 09:21 AM
#127
Unceasing Measure
Re: (hu)
I hope that I can address some things I've read in this thread without pissing in anyone's oatmeal, because that is surely not the reason I read through all of it.
1.) both horsepower and torque - as well as area under the curve - are important in going fast, be it off the line or at 120mph. Neither one is more important than the other as far as performance goes, and both depend on total weight, friction coefficients and moment-inertia when considering their value at any given point/unit time. Good examples of this last statement would be changing tire and suspension configurations on the same car at the drag strip: Car A with 190hp and 115tq might run a 13.8 @ 102 with a stockish configuration, but upgrading to a good set of dampers and some sticky compound rubber might change that time to 13.5 @ 106. Neither hp nor tq was changed (assuming tire diameters of equal value), but the car became "faster"
The only thing this illustrates is the delivery systems are as important as the raw numbers in determining speed.
2.) rod/stroke and the nitty gritty thereof. Anything that increases displacement - empty cylinder volume or combustable air/fuel - will increase torque unless something catastrophic happens in the flow characteristics of the head and combustion chambers as a result. Barring that unlikely circumstance, stroking is a great way to increase torque and, with enough extra flow to compensate for the added cylinder volume, horsepower.
The rod/stroke ratio is not a perfect determination of torque, be it peak or average. The rod/stroke ratio will dictate far more acurately where the torque peak occurs. Head and manifold design takes over largely from there, but the raw torque peak will shift significantly as the stroke is modified - shortened or lengthened.
3.) the whole Honda with 300hp versus 454 Chevy with 300hp etc. arguement. That whole thing is bullshit - as is most of what that member (Daver) has said in this thread. Sweeping generalizations based on life experiences should not be paraded as scientific fact. RWD versus FWD does not dictate victory at a dragstrip or a road course, nor does it determine which car will get out of the hole from a standstill faster. Yes, RWD cars tend to get better 60' times because weight transfer aides the traction of their drive wheels, but that doesn't mean that I didn't hole-shoot the **** out of my roommate's 335hp/345tq Firehawk a week ago with my girlfriend's automatic 2.0L Jetta. Did he swallow me as he shifted to second? Yes, of course, but his failure to launch properly allowed me a tiny, and comical, victory off the line.
Driver matters more than hp or tq or physics or divine intervention. If we're going to continue on the Daver track of broad and baseless generalizations, driver becomes every bit as important as the physics behind his observations.
4.) Redline and its relationship to power. A higher redline equals higher HP from the same amount of torque assuming a head that never loses efficiency. This is why Hondas are potent forces in both straight-line and road racing. Head design and RPM are complimentary to a fault. From a physics standpoint - assuming nothing of the longevity or practicality of a situation - increasing RPM will increase horsepower assuming a constant torque curve...which would be a line in this example.
Does that mean that winding your D16A6 to 12,000rpm is a good idea? Hell no. Revs don't equal hp without torque - read: head and rotational mass design - therefore your average B16A2, as Daver continues to bring up, will indeed not make more hp the higher you rev it because, in a stock configuration, the torque falls off hideously after about 7600rpm and you begin to face the law of diminishing returns. Put cams and a nice valvetrain in the little demon and it'll sing to 10,000, but that's not stock and therefore moot.
In the end, your car will be as fast as the synergy of the parts. HP, TQ and their locations on a graph determine nothing but potential: it's the driver and the suspension that determine the actualized goals regarding lap times or ET's at a given mph.
This is a wonderful thread and I would love to see it continue to flourish, but we must all be aware that generalizing with little scientific backing will do nothing but sew confusion in those who have yet to learn the physics of going fast.
1.) both horsepower and torque - as well as area under the curve - are important in going fast, be it off the line or at 120mph. Neither one is more important than the other as far as performance goes, and both depend on total weight, friction coefficients and moment-inertia when considering their value at any given point/unit time. Good examples of this last statement would be changing tire and suspension configurations on the same car at the drag strip: Car A with 190hp and 115tq might run a 13.8 @ 102 with a stockish configuration, but upgrading to a good set of dampers and some sticky compound rubber might change that time to 13.5 @ 106. Neither hp nor tq was changed (assuming tire diameters of equal value), but the car became "faster"
The only thing this illustrates is the delivery systems are as important as the raw numbers in determining speed.
2.) rod/stroke and the nitty gritty thereof. Anything that increases displacement - empty cylinder volume or combustable air/fuel - will increase torque unless something catastrophic happens in the flow characteristics of the head and combustion chambers as a result. Barring that unlikely circumstance, stroking is a great way to increase torque and, with enough extra flow to compensate for the added cylinder volume, horsepower.
The rod/stroke ratio is not a perfect determination of torque, be it peak or average. The rod/stroke ratio will dictate far more acurately where the torque peak occurs. Head and manifold design takes over largely from there, but the raw torque peak will shift significantly as the stroke is modified - shortened or lengthened.
3.) the whole Honda with 300hp versus 454 Chevy with 300hp etc. arguement. That whole thing is bullshit - as is most of what that member (Daver) has said in this thread. Sweeping generalizations based on life experiences should not be paraded as scientific fact. RWD versus FWD does not dictate victory at a dragstrip or a road course, nor does it determine which car will get out of the hole from a standstill faster. Yes, RWD cars tend to get better 60' times because weight transfer aides the traction of their drive wheels, but that doesn't mean that I didn't hole-shoot the **** out of my roommate's 335hp/345tq Firehawk a week ago with my girlfriend's automatic 2.0L Jetta. Did he swallow me as he shifted to second? Yes, of course, but his failure to launch properly allowed me a tiny, and comical, victory off the line.
Driver matters more than hp or tq or physics or divine intervention. If we're going to continue on the Daver track of broad and baseless generalizations, driver becomes every bit as important as the physics behind his observations.
4.) Redline and its relationship to power. A higher redline equals higher HP from the same amount of torque assuming a head that never loses efficiency. This is why Hondas are potent forces in both straight-line and road racing. Head design and RPM are complimentary to a fault. From a physics standpoint - assuming nothing of the longevity or practicality of a situation - increasing RPM will increase horsepower assuming a constant torque curve...which would be a line in this example.
Does that mean that winding your D16A6 to 12,000rpm is a good idea? Hell no. Revs don't equal hp without torque - read: head and rotational mass design - therefore your average B16A2, as Daver continues to bring up, will indeed not make more hp the higher you rev it because, in a stock configuration, the torque falls off hideously after about 7600rpm and you begin to face the law of diminishing returns. Put cams and a nice valvetrain in the little demon and it'll sing to 10,000, but that's not stock and therefore moot.
In the end, your car will be as fast as the synergy of the parts. HP, TQ and their locations on a graph determine nothing but potential: it's the driver and the suspension that determine the actualized goals regarding lap times or ET's at a given mph.
This is a wonderful thread and I would love to see it continue to flourish, but we must all be aware that generalizing with little scientific backing will do nothing but sew confusion in those who have yet to learn the physics of going fast.
03-25-2006, 10:02 AM
#128
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Re: (Archidictus)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Archidictus »</TD></TR><TR><TD CLASS="quote">
3.) the whole Honda with 300hp versus 454 Chevy with 300hp etc. arguement. That whole thing is bullshit - as is most of what that member (Daver) has said in this thread. Sweeping generalizations based on life experiences should not be paraded as scientific fact. RWD versus FWD does not dictate victory at a dragstrip or a road course, nor does it determine which car will get out of the hole from a standstill faster. Yes, RWD cars tend to get better 60' times because weight transfer aides the traction of their drive wheels, but that doesn't mean that I didn't hole-shoot the **** out of my roommate's 335hp/345tq Firehawk a week ago with my girlfriend's automatic 2.0L Jetta. Did he swallow me as he shifted to second? Yes, of course, but his failure to launch properly allowed me a tiny, and comical, victory off the line.
Driver matters more than hp or tq or physics or divine intervention. If we're going to continue on the Daver track of broad and baseless generalizations, driver becomes every bit as important as the physics behind his observations.
</TD></TR></TABLE>
i'm wondering if i insulted your favourite engine or somthing as your post seems to revolve around ragging on my previous posts. You didn't really disput anything except indicate that i forgot about "driver ability" when comparing configurations. Of course i mentioned it, its rule number one when attempting to compare hp vs. torque into a real life explanation to HELP people understand without putting them to SLEEP with the usual formulas.
The fact that you can hole shot your girlfriend 2.slo jetta to beat a firehawk doesn't help explain hp vs. torque now does it?
I really don't know what your post was about other than to vent and reiterate what been said.
3.) the whole Honda with 300hp versus 454 Chevy with 300hp etc. arguement. That whole thing is bullshit - as is most of what that member (Daver) has said in this thread. Sweeping generalizations based on life experiences should not be paraded as scientific fact. RWD versus FWD does not dictate victory at a dragstrip or a road course, nor does it determine which car will get out of the hole from a standstill faster. Yes, RWD cars tend to get better 60' times because weight transfer aides the traction of their drive wheels, but that doesn't mean that I didn't hole-shoot the **** out of my roommate's 335hp/345tq Firehawk a week ago with my girlfriend's automatic 2.0L Jetta. Did he swallow me as he shifted to second? Yes, of course, but his failure to launch properly allowed me a tiny, and comical, victory off the line.
Driver matters more than hp or tq or physics or divine intervention. If we're going to continue on the Daver track of broad and baseless generalizations, driver becomes every bit as important as the physics behind his observations.
</TD></TR></TABLE>
i'm wondering if i insulted your favourite engine or somthing as your post seems to revolve around ragging on my previous posts. You didn't really disput anything except indicate that i forgot about "driver ability" when comparing configurations. Of course i mentioned it, its rule number one when attempting to compare hp vs. torque into a real life explanation to HELP people understand without putting them to SLEEP with the usual formulas.
The fact that you can hole shot your girlfriend 2.slo jetta to beat a firehawk doesn't help explain hp vs. torque now does it?
I really don't know what your post was about other than to vent and reiterate what been said.
03-25-2006, 01:50 PM
#129
Unceasing Measure
Re: (daver)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by daver »</TD></TR><TR><TD CLASS="quote">i'm wondering if i insulted your favourite engine or somthing as your post seems to revolve around ragging on my previous posts. You didn't really disput anything except indicate that i forgot about "driver ability" when comparing configurations. Of course i mentioned it, its rule number one when attempting to compare hp vs. torque into a real life explanation to HELP people understand without putting them to SLEEP with the usual formulas.</TD></TR></TABLE>
You didn't insult me at all, but you posted a bunch of misinformed incorrect crap and I wanted to clear the water and make sure that people weren't taking your opinion as gospel. Your "observations" as to horsepower and torque and the importance of one over the other are completely incorrect and easilly disproven.
Sorry if my vocabulary isn't jazzy enough for you. I wasn't aware that I needed to dumb it down here.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">The fact that you can hole shot your girlfriend 2.slo jetta to beat a firehawk doesn't help explain hp vs. torque now does it?</TD></TR></TABLE>
Obviously you have the reading comprehension of a third grader. That example was a counterpoint to your little quip about "rear wheel drive cars will win off the line every time!". Of course it doesn't prove anything: neither does anything you said, hence the majority of my post regarding how completely incorrect you are.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I really don't know what your post was about other than to vent and reiterate what been said. </TD></TR></TABLE>
I summed up a lot, cleared up a lot and basically made sure to say aloud that you don't really know what you're talking about. Is that less confusing?
You didn't insult me at all, but you posted a bunch of misinformed incorrect crap and I wanted to clear the water and make sure that people weren't taking your opinion as gospel. Your "observations" as to horsepower and torque and the importance of one over the other are completely incorrect and easilly disproven.
Sorry if my vocabulary isn't jazzy enough for you. I wasn't aware that I needed to dumb it down here.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">The fact that you can hole shot your girlfriend 2.slo jetta to beat a firehawk doesn't help explain hp vs. torque now does it?</TD></TR></TABLE>
Obviously you have the reading comprehension of a third grader. That example was a counterpoint to your little quip about "rear wheel drive cars will win off the line every time!". Of course it doesn't prove anything: neither does anything you said, hence the majority of my post regarding how completely incorrect you are.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote »</TD></TR><TR><TD CLASS="quote">I really don't know what your post was about other than to vent and reiterate what been said.
</TD></TR></TABLE>I summed up a lot, cleared up a lot and basically made sure to say aloud that you don't really know what you're talking about. Is that less confusing?
03-25-2006, 04:29 PM
#130
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Re: (Archidictus)
i don't know who you think you are, or how you got your panties in such a bunch about me, but your completely guilty of what your accusing me of here.
"Obviously you have the reading comprehension of a third grader. That example was a counterpoint to your little quip about "rear wheel drive cars will win off the line every time!". Of course it doesn't prove anything: neither does anything you said, hence the majority of my post regarding how completely incorrect you are."
that's NOT what i said, that's you rewriting what i said, AND completely misinterpreting what i MEANT for some unknown hellbent reason. Obviously driver skill, or lack of, will make or break any "rule." Even your third grade friends could tell you that that. <U>Then</U> add in the million other variables that will influence a scenerio, then go write you phd thesis on hp vs. tq and present to us laymen here on honda-tech.
Anyhow, you may believe what you wish, but i plan to move on. Have some better things to do that have stupid twisted aguments with some kid.
d
"Obviously you have the reading comprehension of a third grader. That example was a counterpoint to your little quip about "rear wheel drive cars will win off the line every time!". Of course it doesn't prove anything: neither does anything you said, hence the majority of my post regarding how completely incorrect you are."
that's NOT what i said, that's you rewriting what i said, AND completely misinterpreting what i MEANT for some unknown hellbent reason. Obviously driver skill, or lack of, will make or break any "rule." Even your third grade friends could tell you that that. <U>Then</U> add in the million other variables that will influence a scenerio, then go write you phd thesis on hp vs. tq and present to us laymen here on honda-tech.
Anyhow, you may believe what you wish, but i plan to move on. Have some better things to do that have stupid twisted aguments with some kid.
d
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What is the best way to compare cars in terms of who would win in a race....HP? Torque? HP/LBS ratio
drsues02
Acura Integra
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