 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Jim Henderson wrote:
> There isn't a linear relationship between the rotational speed of the
> wheels and the speed of the engine.
There is, in a (relatively primitive) manual transmission. There is not,
however, a linear relationship between engine RPM and gasoline usage.
> Similarly, if I apply the brakes to a full stop, the engine doesn't die,
> it idles.
When did you last drive a manual transmission? :-)
--
Darren New / San Diego, CA, USA (PST)
"That's pretty. Where's that?"
"It's the Age of Channelwood."
"We should go there on vacation some time."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 16 May 2008 15:20:56 -0700, Darren New wrote:
> Jim Henderson wrote:
>> There isn't a linear relationship between the rotational speed of the
>> wheels and the speed of the engine.
>
> There is, in a (relatively primitive) manual transmission. There is not,
> however, a linear relationship between engine RPM and gasoline usage.
How many cars use a transmission that would count as "relatively
primitive"? But I do agree that there's not a linear relationship
between RPM and MPG.
>> Similarly, if I apply the brakes to a full stop, the engine doesn't
>> die, it idles.
>
> When did you last drive a manual transmission? :-)
D'oh! I was thinking automatic - I learned to drive on a stick....
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 16 May 2008 21:27:22 +0100, Orchid XP v8 wrote:
> Jim Henderson wrote:
>
>> There isn't a linear relationship between the rotational speed of the
>> wheels and the speed of the engine.
>
> Well that's news.
>
>> If I take my foot off the gas, the engine revs drop. The car may or
>> may not slow down (depending on the road and the landscape).
>
> Not true. The engine revs depend on the speed of the vehicle.
>
> If you don't believe me, try rolling down a hill at 30, and then stick
> the car into 1st gear. Watch the revs go through the roof, even though
> you haven't touched the gas.
>
>> Similarly, if I apply the brakes to a full stop, the engine doesn't
>> die, it idles.
>
> Um, yes it does. Unless...
>
>> Then of course if you put the car in neutral, you've completely
>> disengaged the engine from the wheels.
>
> ...you disenguage the engine from the wheels. Then there really isn't
> any relationship. But as long as the car stays in the same gear, there
> is a fixed relationship.
Perhaps in a manual transmission - in my automatic, though, I'll stick
with what I indicated....I s'pose I could ask my father-in-law when I
talk to him next, since his life's work has been working on cars....
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Jim Henderson wrote:
> Perhaps in a manual transmission - in my automatic, though, I'll stick
> with what I indicated.
Sure. But the automatic has a clutch built into it. That's why you only
have two pedals.
--
Darren New / San Diego, CA, USA (PST)
"That's pretty. Where's that?"
"It's the Age of Channelwood."
"We should go there on vacation some time."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Jim Henderson wrote:
> How many cars use a transmission that would count as "relatively
> primitive"?
One that has distinct manually-shifted gears without synchromesh. Lots
of newer cars have things like variable transmissions.
--
Darren New / San Diego, CA, USA (PST)
"That's pretty. Where's that?"
"It's the Age of Channelwood."
"We should go there on vacation some time."
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 16 May 2008 16:06:35 -0700, Darren New wrote:
> Jim Henderson wrote:
>> Perhaps in a manual transmission - in my automatic, though, I'll stick
>> with what I indicated.
>
> Sure. But the automatic has a clutch built into it. That's why you only
> have two pedals.
True....
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
On Fri, 16 May 2008 16:08:15 -0700, Darren New wrote:
> Jim Henderson wrote:
>> How many cars use a transmission that would count as "relatively
>> primitive"?
>
> One that has distinct manually-shifted gears without synchromesh. Lots
> of newer cars have things like variable transmissions.
Yeah, that's what I'm thinking of, just didn't know the name of it...
Jim
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
>> Given that I'm not sure which whacky units miles are divided into,
>> I'll just convert those to more understandable units, so 75/(3500*60)
>> miles is approximately 57.5 centimeters.
>
> That's the number I arrived at too.
Sure, 1.885 feet per revolution.
> Google also tells me that 75 mph = 33 m/s. Which frankly seems really
> damned fast. (!) I mean, my car is only, like, 4 m long or something...
> That means the car covers almost 10x its own length in 1 second! o_O
>
> No wonder hitting anything is an instant fatality...
Hmm, yeah, 110 feet per second, wear your seatbelt.
0.0027 tsp of gas per cylinder. (other factors ignored).
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Darren New wrote:
> Jim Henderson wrote:
>> Perhaps in a manual transmission - in my automatic, though, I'll stick
>> with what I indicated.
>
> Sure. But the automatic has a clutch built into it. That's why you only
> have two pedals.
>
http://en.wikipedia.org/wiki/Variomatic
just plugging dutch technology that never really caught on.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
> Perhaps in a manual transmission - in my automatic, though, I'll stick
> with what I indicated...
Oh, well, yeah. Automatic transmission basically means it can change
gear and lock/unlock the clutch at will. And doing both of those things
changes the relationship. ;-)
My car has manual transmission.
--
http://blog.orphi.me.uk/
http://www.zazzle.com/MathematicalOrchid*
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
