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Spud Demon
Guest
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 Posted:
Mon Sep 26, 2005 8:32 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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TLittle <mail@mail.net> writes in article <432D1CDA.E029CA73@mail.net> dated Sun, 18 Sep 2005 07:52:40 GMT:
| Quote: | What's the point of the tachometer on a vehicle with an automatic
transmission?
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So you can detect a stall at a traffic light without turning the stereo
down. :^)
| Quote: | Seriously, based on my understanding of WHY the tachometer exists, why
are there tachs on vehicles with automatic transmissions?
|
Most automatic transmissions have low-gear settings. It would be a good
thing to know when you're at the upper range of one of these.
-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.
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~^Johnny^~
Guest
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| Posted:
Tue Sep 27, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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On Sun, 18 Sep 2005 13:03:39 -0700, "Alan Johnson" <ajisok@nospam.com>
wrote:
| Quote: |
"tom" <tjctransport@optonline.net> wrote in message
news:%O9Xe.7626$IC3.6900@fe12.lga...
(fucking idiot text snipped)
I drive in Montana. It's nice to know when I'm approaching redline on the
tach when I have my foot to the floor.
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Modern cars have rev limiters.
....NEXT!!!
--
-john
wide-open at throttle dot info |
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~^Johnny^~
Guest
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| Posted:
Tue Sep 27, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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On Mon, 19 Sep 2005 09:20:14 -0500, Steve <no@spam.thanks> wrote:
| Quote: | Hell- go out and get in many new cars (one
I know for certain- Ford Expedition) and floor it in neutral and see
what happens. OK, I'll tell you- the throttle-by-wire revs it up to
about 3600 RPM and it sits there happy as a clam.. Some aren't quite as
graceful- a GM 3800 I had as a rental didn't have throttle-by-wire, so
it just cuts the fuel and the engine will "surge" around 4000 RPM.
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My old '87 T-Bird "redlines" at 5000, and the rev limit is factory
set to 5500. I'm not kidding.
BUT: I could buy a PROM chip which would crank it up to about 5700
RPM and modify the VE mapping, to give me about 9% more horsepower.
Hmmm........
So, what is redline, anyway? 500 RPM before it blows up? :-)
It's kind'a like the torque on Honda motorcycle cylinder head bolts.
No torque wrench, or can't get the damn torque wrench in there?
No problem! The correct torque is: "a quarter turn before it strips".
--
-john
wide-open at throttle dot info
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~^Johnny^~
Guest
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| Posted:
Tue Sep 27, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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On Mon, 19 Sep 2005 21:31:40 -0700, "Alan Johnson" <ajisok@nospam.com>
wrote:
| Quote: | Yeah, but an electronic auto trans will force a shift before "redline"
no matter what you do ANYWAY.
Of course not. I was referring to redlining when approaching top end. Like
at 130 mph in my IROC
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I thought you were referring to my Enzo. Never mind.
--
-john
wide-open at throttle dot info |
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Alan Baker
Guest
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| Posted:
Tue Sep 27, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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In article <kuohj194f5ip2ig7bhkkls07f93lhkq4j8@4ax.com>,
~^Johnny^~ <nospam@gyrogearloose.com> wrote:
| Quote: | On Mon, 19 Sep 2005 09:20:14 -0500, Steve <no@spam.thanks> wrote:
Hell- go out and get in many new cars (one
I know for certain- Ford Expedition) and floor it in neutral and see
what happens. OK, I'll tell you- the throttle-by-wire revs it up to
about 3600 RPM and it sits there happy as a clam.. Some aren't quite as
graceful- a GM 3800 I had as a rental didn't have throttle-by-wire, so
it just cuts the fuel and the engine will "surge" around 4000 RPM.
My old '87 T-Bird "redlines" at 5000, and the rev limit is factory
set to 5500. I'm not kidding.
BUT: I could buy a PROM chip which would crank it up to about 5700
RPM and modify the VE mapping, to give me about 9% more horsepower.
Hmmm........
So, what is redline, anyway? 500 RPM before it blows up? :-)
It's kind'a like the torque on Honda motorcycle cylinder head bolts.
No torque wrench, or can't get the damn torque wrench in there?
No problem! The correct torque is: "a quarter turn before it strips".
|
Isn't that usually quoted: "Torque it until it strips and then back off
a quarter turn"?
:-)
--
Alan Baker
Vancouver, British Columbia
"If you raise the ceiling 4 feet, move the fireplace from that wall
to that wall, you'll still only get the full stereophonic effect
if you sit in the bottom of that cupboard." |
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John S.
Guest
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| Posted:
Tue Sep 27, 2005 6:13 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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Spud Demon wrote:
| Quote: | TLittle <mail@mail.net> writes in article <432D1CDA.E029CA73@mail.net> dated Sun, 18 Sep 2005 07:52:40 GMT:
What's the point of the tachometer on a vehicle with an automatic
transmission?
So you can detect a stall at a traffic light without turning the stereo
down. :^)
Seriously, based on my understanding of WHY the tachometer exists, why
are there tachs on vehicles with automatic transmissions?
Most automatic transmissions have low-gear settings.
|
Yes, most automatic and manual transmissions have a low gear setting.
| Quote: | It would be a good
thing to know when you're at the upper range of one of these.
|
An automatic transmission takes care of that automatically.
| Quote: |
-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer. |
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Ted B.
Guest
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| Posted:
Tue Sep 27, 2005 6:37 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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| Quote: |
An automatic transmission takes care of that automatically.
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You do know that all auto trannies allow you to shift down, right? -Dave |
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John S.
Guest
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| Posted:
Tue Sep 27, 2005 6:50 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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Ted B. wrote:
| Quote: |
An automatic transmission takes care of that automatically.
You do know that all auto trannies allow you to shift down, right? -Dave
|
Yes, as do manual transmissions. And your point is...... |
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Ted B.
Guest
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| Posted:
Tue Sep 27, 2005 8:29 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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| Quote: | You do know that all auto trannies allow you to shift down, right? -Dave
Yes, as do manual transmissions. And your point is......
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That RPMs can get awfully darn high when you downshift. While a tachometer
isn't absolutely necessary (regardless of transmission), it is useful
(regardless of transmission) -Dave |
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~^Johnny^~
Guest
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| Posted:
Wed Sep 28, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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On Tue, 27 Sep 2005 06:35:41 GMT, Alan Baker <alangbaker@telus.net>
wrote:
| Quote: | In article <kuohj194f5ip2ig7bhkkls07f93lhkq4j8@4ax.com>,
~^Johnny^~ <nospam@gyrogearloose.com> wrote:
The correct torque is: "a quarter turn before it strips".
Isn't that usually quoted: "Torque it until it strips and then back off
a quarter turn"?
:-)
|
But by then, it's too late, you see...
....it's already been stripped! ;->
I'd hate to tell you how they test fuses...
--
-john
wide-open at throttle dot info |
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Guest
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| Posted:
Thu Sep 29, 2005 4:50 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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haven't read the entire thread but looks like this is the first
"correct" answer:
When descending a hill, with the automatic transmission selector lever
in low gear, like "L" or "2", the tachometer can be used to insure you
do not exceed redline and incur engine damage, which when locked
manually in the lower gear is possible. |
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Steve
Guest
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| Posted:
Thu Sep 29, 2005 7:07 pm Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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nospampls2002@yahoo.com wrote:
| Quote: | haven't read the entire thread but looks like this is the first
"correct" answer:
When descending a hill, with the automatic transmission selector lever
in low gear, like "L" or "2", the tachometer can be used to insure you
do not exceed redline and incur engine damage, which when locked
manually in the lower gear is possible.
|
True for older purely hydro-mechanical transmissions. But name me an
automatic transmission currently made that won't upshift at or before
redline REGARDLESS of what gear is selected. There are probably a few
still out there, but not many. |
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John S.
Guest
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| Posted:
Sat Oct 01, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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nospampls2002@yahoo.com wrote:
| Quote: | haven't read the entire thread but looks like this is the first
"correct" answer:
When descending a hill, with the automatic transmission selector lever
in low gear, like "L" or "2", the tachometer can be used to insure you
do not exceed redline and incur engine damage, which when locked
manually in the lower gear is possible.
|
If you don't know what will happen prior to moving the shift lever a
tachometer won't solve that problem. You would be much better off
leaving the car in drive if you can't avoid overrevving an engine by
dropping to the next lower gear.
A tach is for the most part low grade visual entertainment - watch the
moving needle. |
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John S.
Guest
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| Posted:
Sat Oct 01, 2005 8:12 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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Ted B. wrote:
| Quote: | You do know that all auto trannies allow you to shift down, right? -Dave
Yes, as do manual transmissions. And your point is......
That RPMs can get awfully darn high when you downshift. While a tachometer
isn't absolutely necessary (regardless of transmission), it is useful
(regardless of transmission) -Dave
|
Please don't take this personally, but if you don't have a good idea
what will happen to engine speed when you downshift a tachometer will
not do much to solve that problem. If you drop it into an
inappropriately low gear the tach will only tell you after the fact
that you screwed up and overrevved the engine. Engine noise will tell
you roughly the same thing. I would strongly suggest that you just
leave the transmission in Drive and let brakes do the work of slowing
the car. |
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Agave
Guest
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| Posted:
Sun Oct 02, 2005 6:57 am Post subject:
Re: Why do cars with automatic transmissions have tachometer |
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<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
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<head>
<meta content="text/html;charset=ISO-8859-1" http-equiv="Content-Type">
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Spud Demon wrote:
<blockquote cite="middh9lt4$3ad$2@newslocal.mitre.org" type="cite">
<pre wrap="">TLittle <a class="moz-txt-link-rfc2396E" href="mailto:mail@mail.net"><mail@mail.net></a> writes in article <a class="moz-txt-link-rfc2396E" href="mailto:432D1CDA.E029CA73@mail.net"><432D1CDA.E029CA73@mail.net></a> dated Sun, 18 Sep 2005 07:52:40 GMT:
</pre>
<blockquote type="cite">
<pre wrap="">What's the point of the tachometer on a vehicle with an automatic
transmission?
</pre>
</blockquote>
<pre wrap=""><!---->
So you can detect a stall at a traffic light without turning the stereo
down. :^)
</pre>
<blockquote type="cite">
<pre wrap="">Seriously, based on my understanding of WHY the tachometer exists, why
are there tachs on vehicles with automatic transmissions?
</pre>
</blockquote>
<pre wrap=""><!---->
Most automatic transmissions have low-gear settings. It would be a good
thing to know when you're at the upper range of one of these.
-- spud_demon -at- thundermaker.net
The above may not (yet) represent the opinions of my employer.
</pre>
</blockquote>
I offer the following; it hasn't to do with why or when to use a tach
with an automatic transmission, but rather why there's a tach in an
automobile with an automatic transmission at all.<br>
<br>
It's more cost effective for the manufacturer to include a tach in all
models where a tach would otherwise be an option. As I postulate, it's
cost effective from the design, manufacturing, procurement, assembly,
and all other aspects for the manufacturer, not necessarily the
consumer. All consumers pay a small price for a gauge few will ever
use, even those with a manual transmission.<br>
<br>
This is especially apparent when you consider the similarities (i.e.,
cost effectiveness) among models, not only with the gauges, but also
the supporting electronics as well.<br>
<br>
Similar to, but different than...why are automatic transmissions even
offered in certain vehicles, for example: Jeep Wrangler, Corvette, and
4x4 Trucks. I already know the answer, but it still makes me laugh a
bit when I pull up next to a "sports car" and look down and see an
automatic shifter.<br>
<br>
<div align="left"><i><font color="#009900">Agave</font></i><br>
</div>
<i><font color="#009900">Salud, dinero, amor y tiempo
para disfrutarlos<br>
01 F350 PSD Crew Dually</font></i><br>
</body>
</html> |
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