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Old 02-16-2009, 07:09 PM   #21
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Originally Posted by kotomile View Post
That's far too simple and concise for this crowd.

Sav and Pat - FWIW - When I mentioned what it is you "feel", I was answering a specific question asked by the OP. No need to whip out the slide rules.
I know. You feel the torque at the wheels that pushes against the road, causing an acceleration. But when Sav said you feel the change in acceleration, I thought I would clarify. You're right, torque is what you "feel".
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Old 02-16-2009, 07:36 PM   #22
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I was kind of hoping someone would ask "What's a slide rule?"
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Old 02-16-2009, 07:49 PM   #23
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I have a slide rule.
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Old 02-16-2009, 08:00 PM   #24
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Originally Posted by patsmx5 View Post
Yall call it whatever you want. I've had college level physics and calculus, so I define things the way I was taught to. You say you "feel" something when full boost hits. What do you think you feel? What's happening when you feel this? Is your velocity changing at a very fast rate? Change in velocity with respect to time? Is that acceleration? What?

My first post tried to explain this a bit and it went over the OP's and other's respective heads.
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Velocity is a function of speed and time. The function of velocity and time is acceleration.

What they are feeling is the change in the moment of inertia.
A friend of mine has taken a few physics classes as well.
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Old 02-16-2009, 08:03 PM   #25
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A friend of mine has taken a few physics classes as well.
Nice avatar.
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Old 02-16-2009, 08:07 PM   #26
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Nice avatar.
Read it and know it. You'll eventually learn.

Incase you didn't understand...someone else changed the avatar, but it certainly applies to alot of the people who read it on this forum. You would be one of them. It's ok to be GAY. I've given up trying to change you, so continue with the gayness.
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Old 02-16-2009, 08:13 PM   #27
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Originally Posted by patsmx5 View Post
Yall call it whatever you want. I've had college level physics and calculus, so I define things the way I was taught to. You say you "feel" something when full boost hits. What do you think you feel? What's happening when you feel this? Is your velocity changing at a very fast rate? Change in velocity with respect to time? Is that acceleration? What?

My first post tried to explain this a bit and it went over the OP's and other's respective heads.
Actually, your explanation of what torque is was spot-on - absolutely no quibbles there. I was merely observing that a changing rate of acceleration ('Jerk', or v/s/s/s) is more entertaining than a constant rate of acceleration (v/s/s). Rollercoasters (which most of us will agree are great fun) constantly accelerate, but in different directions and at different rates.

People undergo something called "accomodation", whereby we get used to an experience and it no longer captures the brain's attention (getting into a hot bath may initially take your breath away, but you get used to it quickly). This characteristic is why cocaine addicts eventually OD.

As to what happens when boost hits, of course we undergo acceleration. However, look at the torque curve of a typical turbocharged car, which is bell-shaped. As boost ramps up, we experience acceleration, but because the torque curve is increasing, we also experience a change in the rate of acceleration (Jerk). A car with a very flat torque curve may throw your head against the headrest upon throttle application (whee!) but once the curve plateaus, so do the thrills. This outlines the main reason I went the route I did with my build and discounted a V8 conversion.
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Old 02-16-2009, 08:34 PM   #28
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Quote:
Originally Posted by DeerHunter View Post
Actually, your explanation of what torque is was spot-on - absolutely no quibbles there. I was merely observing that a changing rate of acceleration ('Jerk', or v/s/s/s) is more entertaining than a constant rate of acceleration (v/s/s). Rollercoasters (which most of us will agree are great fun) constantly accelerate, but in different directions and at different rates.

People undergo something called "accomodation", whereby we get used to an experience and it no longer captures the brain's attention (getting into a hot bath may initially take your breath away, but you get used to it quickly). This characteristic is why cocaine addicts eventually OD.

As to what happens when boost hits, of course we undergo acceleration. However, look at the torque curve of a typical turbocharged car, which is bell-shaped. As boost ramps up, we experience acceleration, but because the torque curve is increasing, we also experience a change in the rate of acceleration (Jerk). A car with a very flat torque curve may throw your head against the headrest upon throttle application (whee!) but once the curve plateaus, so do the thrills. This outlines the main reason I went the route I did with my build and discounted a V8 conversion.
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Where the torque curve is flat your moment of inertia is 0.
My friend said you are spot on, and he likes the way you explain it.
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Old 02-16-2009, 08:41 PM   #29
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Uh, if torque is holding flat, then power is increasing as is torque to the wheels. In such case acceleration would be increasing.
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Old 02-16-2009, 08:52 PM   #30
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Originally Posted by patsmx5 View Post
Uh, if torque is holding flat, then power is increasing as is torque to the wheels. In such case acceleration would be increasing.
If the torque is holding flat, then the torque is NOT increasing.
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Old 02-16-2009, 08:54 PM   #31
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Pat, everyone is accelerating at all times since we're in orbit around the sun (among other reasons). We don't "feel" that acceleration since we're used to it. Constant acceleration would be just slightly more than enough horsepower to overcome the drag at a certain speed, and it would be terribly boring. The fun in a fast car comes from the rapid increase in the rate of acceleration.
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Old 02-16-2009, 09:25 PM   #32
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Originally Posted by ray_sir_6 View Post
If the torque is holding flat, then the torque is NOT increasing.
You didn't read what I typed. Let me clarify though. If torque at the engine is holding flat while RPMs are increasing, then power is increasing, as is torque to the wheels. Therefore the acceleration is increasing.

Sav- acceleration due to gravity? Pretty sure we feel that all the time.
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Old 02-16-2009, 09:27 PM   #33
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Originally Posted by Savington View Post
Pat, everyone is accelerating at all times since we're in orbit around the sun (among other reasons). We don't "feel" that acceleration since we're used to it. Constant acceleration would be just slightly more than enough horsepower to overcome the drag at a certain speed, and it would be terribly boring. The fun in a fast car comes from the rapid increase in the rate of acceleration.
Constant positive acceleration would be insane. I dare say boring.
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Old 02-16-2009, 10:09 PM   #34
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I think what the above posters are arguing is called impulse. Jerk and surge are good descriptions though.
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Old 02-16-2009, 10:33 PM   #35
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Originally Posted by gospeed81 View Post
I think what the above posters are arguing is called impulse. Jerk and surge are good descriptions though.
See:
http://en.wikipedia.org/wiki/Jerk_(physics)
Third derivative of position

Interestingly, I first heard the term during an interview with a Mazda engineer who helped develop the powertrain for the NA. He said that they aimed for a rising torque curve since the resulting "jerk" force increased the fun-to-drive factor.

Found the reference with a quick Google search:
http://books.google.com/books?id=gLA...um=1&ct=result
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Old 02-16-2009, 10:38 PM   #36
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Quote:
Originally Posted by linkz
So far yank (symbol Y) has been suggested for rate of change of force, tug (symbol T) for rate of change of yank, ****** (symbol S) for rate of change of tug and shake (symbol Sh) for rate of change of ******. Needless to say, none of these are in any kind of standards, yet. We just made them up on usenet.
I prefer the term ****** whenever possible.
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Old 02-16-2009, 10:48 PM   #37
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Originally Posted by patsmx5 View Post
Sav- acceleration due to gravity? Pretty sure we feel that all the time.
centripetal acceleration. from the sun whipping us around the galaxy in a large circle.
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Old 02-16-2009, 11:58 PM   #38
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horsepower is how fast you're going when you hit the wall, torque is how far you take it with you.

in all seriousness, torque is a weird thing. look at diesels, 1000 ft/lb, 500hp, revs to 4k max. lol. from what i understand, typically the longer the stroke, the more torque you usually have, i may be wrong though.
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Old 02-17-2009, 12:10 AM   #39
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The longer the stroke, the greater the mechanical advantage, yes.
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Old 02-17-2009, 10:33 AM   #40
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Originally Posted by Toddcod View Post

Basically when old timers are throwing out the slang, torque motor and HP motor. They are basically refering to the above instance. Like if the motor just blast out but runs out of snuff quick. It is considered torque'y. And if you have to have the rpms up to get the power you want they call that a hp motor.
Amazing. My dad has been talking about motors like this since I could remember, never could clearly understand what he meant until now.
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